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new owner questions [message #320092] Fri, 07 July 2017 11:33 Go to next message
joewilly is currently offline  joewilly   United States
Messages: 40
Registered: April 2016
Location: Victor,Ia
Karma: -1
Member
Hello all, I just purchased my first GMC last week. 1978 Royale rear twin and had a good trip back to Iowa from Wyoming (850 mi) with no issues. So now I have been going over everything and have found a few things that need attention and would appreciate any advice all you experts can give me.
the first is I have a split cv boot on the drivers side, cv joint not making any noise yet.
Is it best to R & R it with a rebuilt axle or try to remove old boot and replace with new boot.
How time consuming and challenging is this job for a newbie?
I see that some have used the split boot option with good and bad results.any opinions on this?
question #2 - It has a 4 bag rear suspension, Leigh Harrison 1999 (I think) and the bag pressure is 110 psi on the driver side and 100 psi on the pass. side. does this sound normal for this system? it seems high to me, and do you adjust the pressure at the air compressor? it's at 112 psi

any info is greatly appreciated.
thanks, Joe


Joe Williams 1978 Royale rear twin
Re: new owner questions [message #320093 is a reply to message #320092] Fri, 07 July 2017 11:49 Go to previous messageGo to next message
lqqkatjon is currently offline  lqqkatjon   United States
Messages: 2324
Registered: October 2010
Location: St. Cloud, MN
Karma: 5
Senior Member
Welcome.

I dont believe you need to replace the axle. You should be just fine installing a new boot. Like you said there are
Both success
Stories and failures of split boots, but I have also had my own failures of non-split boots.

The job itself is messy, but not at all impossible. I have done a few, and I just remove tire/rim and axle nut, pop the tie rod off the knuckle and I can muscle the outer cv ut and over to be able to install a boot. It takes some muscle to flex it to come out, but do-able. I personally have only installed non-split boots and I like the dorman one now. Have had failures on some others, but the dorman one has been good now for 3-4 years.

I know a few that have a year or two and longer on some dorman split boot as well.

I do not know about your airbag system, but coach is heavier on driver side due to onan generator, so i am just guessing it is normal pressures.



Jon Roche 75 palm beach EBL EFI, manny headers, Micro Level, rebuilt most of coach now. St. Cloud, MN http://lqqkatjon.blogspot.com/
Re: [GMCnet] new owner questions [message #320094 is a reply to message #320092] Fri, 07 July 2017 11:41 Go to previous messageGo to next message
jimk is currently offline  jimk   United States
Messages: 6734
Registered: July 2006
Location: Belmont, CA
Karma: 9
Senior Member
Joe,
Depending on the milage on the coach, one might just replace the boot.
Two piece is ok, but I suggest a one piece.
Give me a so we can discuss.
On the Harrison system,it does require high pressure, just set the height
correctly.
I can also give you that info.

On Fri, Jul 7, 2017 at 9:33 AM, Joe williams wrote:

> Hello all, I just purchased my first GMC last week. 1978 Royale rear twin
> and had a good trip back to Iowa from Wyoming (850 mi) with no issues. So
> now I have been going over everything and have found a few things that
> need attention and would appreciate any advice all you experts can give me.
> the first is I have a split cv boot on the drivers side, cv joint not
> making any noise yet.
> Is it best to R & R it with a rebuilt axle or try to remove old boot and
> replace with new boot.
> How time consuming and challenging is this job for a newbie?
> I see that some have used the split boot option with good and bad
> results.any opinions on this?
> question #2 - It has a 4 bag rear suspension, Leigh Harrison 1999 (I
> think) and the bag pressure is 110 psi on the driver side and 100 psi on the
> pass. side. does this sound normal for this system? it seems high to me,
> and do you adjust the pressure at the air compressor? it's at 112 psi
>
> any info is greatly appreciated.
> thanks, Joe
>
> --
> jwilly
> 1978 Royale rear twin
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>



--
Jim Kanomata
Applied/GMC, Newark,CA
jimk@appliedairfilters.com
http://www.appliedgmc.com
1-800-752-7502
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Jim Kanomata
Applied/GMC
jimk@appliedairfilters.com
www.appliedgmc.com
1-800-752-7502
Re: [GMCnet] new owner questions [message #320095 is a reply to message #320092] Fri, 07 July 2017 12:18 Go to previous messageGo to next message
bdub is currently offline  bdub   United States
Messages: 1578
Registered: February 2004
Location: Central Texas
Karma: 5
Senior Member

Hi Joe
Welcome to the family.
Just replace the boot and add more grease. Jim will sell you what you need.
Call him at 800 752 7502. www.appliedgmc.com

The rear air springs are to control the ride height. Pressure doesn't matter
much.

bdub

76 Palm Beach in Central Texas
www.bdub.net/GMCLinks.html
www.gmcmotorhomemarketplace.com
https://www.facebook.com/groups/classicgmcmotorhomes/
https://www.facebook.com/groups/gmcmm/

GMCnet email list - http://www.gmcnet.org/
GMCnet forum mirror http://gmc.mybirdfeeder.net/GMCforum/

-----Original Message-----
From: Gmclist] On Behalf Of Joe williams
Sent: Friday, July 7, 2017 11:34 AM
Hello all, I just purchased my first GMC last week. 1978 Royale rear twin and
had a good trip back to Iowa from Wyoming (850 mi) with no issues. So now I have
been going over everything and have found a few things that need attention and
would appreciate any advice all you experts can give me.
the first is I have a split cv boot on the drivers side, cv joint not making any
noise yet.
Is it best to R & R it with a rebuilt axle or try to remove old boot and replace
with new boot.
How time consuming and challenging is this job for a newbie?
I see that some have used the split boot option with good and bad results.any
opinions on this?
question #2 - It has a 4 bag rear suspension, Leigh Harrison 1999 (I think) and
the bag pressure is 110 psi on the driver side and 100 psi on the pass. side.
does this sound normal for this system? it seems high to me, and do you adjust
the pressure at the air compressor? it's at 112 psi



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bdub
'76 Palm Beach/Central Texas
www.bdub.net
www.gmcmhphotos.com
www.gmcmotorhomemarketplace.com
www.gmcmhregistry.com
www.facebook.com/groups/classicgmcmotorhomes
www.facebook.com/groups/gmcmm
Re: [GMCnet] new owner questions [message #320097 is a reply to message #320092] Fri, 07 July 2017 12:25 Go to previous messageGo to next message
Emery Stora is currently offline  Emery Stora   United States
Messages: 959
Registered: January 2011
Karma: 4
Senior Member
I would suggest raising the pressure a bit — perhaps 120 to 130 psi. This will allow the bags to raise higher when leveling at a campsite and allow the system to fill the bags slightly faster.
Most single OEM bag systems are around 90 psi for ride height but I think I read once that the Harrison system needs more pressure to level the GMC.

Emery Stora
77 Kingsley
Frederick, CO

> On Jul 7, 2017, at 10:33 AM, Joe williams wrote:
>
> Hello all, I just purchased my first GMC last week. 1978 Royale rear twin and had a good trip back to Iowa from Wyoming (850 mi) with no issues. So
> now I have been going over everything and have found a few things that need attention and would appreciate any advice all you experts can give me.
> the first is I have a split cv boot on the drivers side, cv joint not making any noise yet.
> Is it best to R & R it with a rebuilt axle or try to remove old boot and replace with new boot.
> How time consuming and challenging is this job for a newbie?
> I see that some have used the split boot option with good and bad results.any opinions on this?
> question #2 - It has a 4 bag rear suspension, Leigh Harrison 1999 (I think) and the bag pressure is 110 psi on the driver side and 100 psi on the
> pass. side. does this sound normal for this system? it seems high to me, and do you adjust the pressure at the air compressor? it's at 112 psi
>
> any info is greatly appreciated.
> thanks, Joe
>
> --
> jwilly
> 1978 Royale rear twin
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org


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Re: new owner questions [message #320100 is a reply to message #320092] Fri, 07 July 2017 13:26 Go to previous messageGo to next message
Matt Colie is currently offline  Matt Colie   United States
Messages: 8547
Registered: March 2007
Location: S.E. Michigan
Karma: 7
Senior Member
Joe,

Welcome to the group, family, cult, asylum.....

A friend that sometimes writes here is now running 2 split boots. He has not been able to use the coach as much as he might have liked, but the boots have not been an issue. They are bags easier to get on than the usual boot, but it is still a mess. He did do one without even getting the axle clear of the hub. I would say that if you want to put on a usual boot, it is worth your while (including new screws and Loktite) to get the drive axle out where you can wrestle with it standing up.

After having cars with axle boots for about 40 years, I can say that taking care of it sooner beats buying a replacement joint.

You have already found the value of this community, and that puts you out ahead of many new owners. I would like to ask you to add your location to your sigfile. This forum started out as a e-mail list and many still read it that way, so they don't see the header where your location is published.

About this community, it is like few others. I have seen it rally to aid of an owner more times than I can count (yours truly is included there), and it is a thing of beauty. The only other community that I know of like this is that of the watermen that are my world. For this reason, I like to welcome new owners much as a new owner or vessel is welcomed there. So,

May the Good Lord bless this coach and all those that set forth within her.

Welcome Joe

Matt


Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit
Re: [GMCnet] new owner questions [message #320101 is a reply to message #320097] Fri, 07 July 2017 13:37 Go to previous messageGo to next message
jimk is currently offline  jimk   United States
Messages: 6734
Registered: July 2006
Location: Belmont, CA
Karma: 9
Senior Member
The pressure is one of the main reason Jim Bounds of Coop Mtrs consulted
with us to come up with a system that would give same control performance
in the rear suspension and have lower air pressure requirement.
Tha is when we developed the Quadra Bag System that stabilizes the rear and
run on 80-85 psi .

On Fri, Jul 7, 2017 at 10:25 AM, Emery Stora wrote:

> I would suggest raising the pressure a bit — perhaps 120 to 130 psi. This
> will allow the bags to raise higher when leveling at a campsite and allow
> the system to fill the bags slightly faster.
> Most single OEM bag systems are around 90 psi for ride height but I think
> I read once that the Harrison system needs more pressure to level the GMC.
>
> Emery Stora
> 77 Kingsley
> Frederick, CO
>
>> On Jul 7, 2017, at 10:33 AM, Joe williams wrote:
>>
>> Hello all, I just purchased my first GMC last week. 1978 Royale rear
> twin and had a good trip back to Iowa from Wyoming (850 mi) with no issues.
> So
>> now I have been going over everything and have found a few things that
> need attention and would appreciate any advice all you experts can give me.
>> the first is I have a split cv boot on the drivers side, cv joint not
> making any noise yet.
>> Is it best to R & R it with a rebuilt axle or try to remove old boot and
> replace with new boot.
>> How time consuming and challenging is this job for a newbie?
>> I see that some have used the split boot option with good and bad
> results.any opinions on this?
>> question #2 - It has a 4 bag rear suspension, Leigh Harrison 1999 (I
> think) and the bag pressure is 110 psi on the driver side and 100 psi on the
>> pass. side. does this sound normal for this system? it seems high to me,
> and do you adjust the pressure at the air compressor? it's at 112 psi
>>
>> any info is greatly appreciated.
>> thanks, Joe
>>
>> --
>> jwilly
>> 1978 Royale rear twin
>>
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>



--
Jim Kanomata
Applied/GMC, Newark,CA
jimk@appliedairfilters.com
http://www.appliedgmc.com
1-800-752-7502
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Jim Kanomata
Applied/GMC
jimk@appliedairfilters.com
www.appliedgmc.com
1-800-752-7502
Re: [GMCnet] new owner questions [message #320102 is a reply to message #320094] Fri, 07 July 2017 13:54 Go to previous messageGo to next message
James Hupy is currently offline  James Hupy   United States
Messages: 6806
Registered: May 2010
Karma: -62
Senior Member
Anything over 100 psi is not advised by either Firestone or the
manufacturer of the 72000 controller. They are both adamant in their
opposition to higher pressures and limit their remote controllers to
100psi. I have been in contact with both of them and requested that they
allow me to reprogram their systems to allow higher pressures. Both refused
to do so. As Firestone makes the bags, they probably know the safe high
limits. On single bag systems, you can add extenders to the bogie that
lowers the pressure quite a bit, that will get the system to full
extension. I don't know why you would need it to pump any more air than
that. I suspect it might be the old horsepower thing."You can never have
too much money, a girlfriend too pretty, or too much horsepower". Same
applies to air pressure, I suspect.
Jim Hupy
Salem, Or
78 GMC ROYALE 403

On Jul 7, 2017 11:38 AM, "Jim Kanomata" wrote:

The pressure is one of the main reason Jim Bounds of Coop Mtrs consulted
with us to come up with a system that would give same control performance
in the rear suspension and have lower air pressure requirement.
Tha is when we developed the Quadra Bag System that stabilizes the rear and
run on 80-85 psi .

On Fri, Jul 7, 2017 at 10:25 AM, Emery Stora wrote:

> I would suggest raising the pressure a bit — perhaps 120 to 130 psi. This
> will allow the bags to raise higher when leveling at a campsite and allow
> the system to fill the bags slightly faster.
> Most single OEM bag systems are around 90 psi for ride height but I think
> I read once that the Harrison system needs more pressure to level the GMC.
>
> Emery Stora
> 77 Kingsley
> Frederick, CO
>
>> On Jul 7, 2017, at 10:33 AM, Joe williams wrote:
>>
>> Hello all, I just purchased my first GMC last week. 1978 Royale rear
> twin and had a good trip back to Iowa from Wyoming (850 mi) with no
issues.
> So
>> now I have been going over everything and have found a few things that
> need attention and would appreciate any advice all you experts can give
me.
>> the first is I have a split cv boot on the drivers side, cv joint not
> making any noise yet.
>> Is it best to R & R it with a rebuilt axle or try to remove old boot and
> replace with new boot.
>> How time consuming and challenging is this job for a newbie?
>> I see that some have used the split boot option with good and bad
> results.any opinions on this?
>> question #2 - It has a 4 bag rear suspension, Leigh Harrison 1999 (I
> think) and the bag pressure is 110 psi on the driver side and 100 psi on
the
>> pass. side. does this sound normal for this system? it seems high to me,
> and do you adjust the pressure at the air compressor? it's at 112 psi
>>
>> any info is greatly appreciated.
>> thanks, Joe
>>
>> --
>> jwilly
>> 1978 Royale rear twin
>>
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>



--
Jim Kanomata
Applied/GMC, Newark,CA
jimk@appliedairfilters.com
http://www.appliedgmc.com
1-800-752-7502
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Re: [GMCnet] new owner questions [message #320105 is a reply to message #320102] Fri, 07 July 2017 14:24 Go to previous messageGo to next message
emerystora is currently offline  emerystora   United States
Messages: 4442
Registered: January 2004
Karma: 13
Senior Member
Well, I've owned my motorhome for 36 years now and the air tank pressure has been set at 130 psi most of that time.
When traveling the bags are at approximately 90 psi.
When parking on a non-level campsite they have occasionally been pumped up as high as 130. No adverse effects. The original bags lasted for over thirty years.
You say you don't know why anyone would need over 100 psi. You might consider being able to level it better at a campsite as a reason.

By the way take a look at the GMC Maintenance manual X7725. Page 4A9-4A10 says the compressor will shut off at 120 psi. Also on page 4A10 in the paragraph PRESSURE SWITCH it says " The air pressure switch is designed to maintain air pressure in the wet tank between 100 and 120 psi. Switch activates at 100 psi and opens at 120 psi.
You might want to go back to Firestone and your manufacturer of the 72000 controller and point out to them that GM used 120 psi in the bags, NOT 100 psi.

Emery Stora
77 Kingsley
Frederick, CO

> On Jul 7, 2017, at 12:54 PM, James Hupy wrote:
>
> Anything over 100 psi is not advised by either Firestone or the
> manufacturer of the 72000 controller. They are both adamant in their
> opposition to higher pressures and limit their remote controllers to
> 100psi. I have been in contact with both of them and requested that they
> allow me to reprogram their systems to allow higher pressures. Both refused
> to do so. As Firestone makes the bags, they probably know the safe high
> limits. On single bag systems, you can add extenders to the bogie that
> lowers the pressure quite a bit, that will get the system to full
> extension. I don't know why you would need it to pump any more air than
> that. I suspect it might be the old horsepower thing."You can never have
> too much money, a girlfriend too pretty, or too much horsepower". Same
> applies to air pressure, I suspect.
> Jim Hupy
> Salem, Or
> 78 GMC ROYALE 403
>
> On Jul 7, 2017 11:38 AM, "Jim Kanomata" wrote:
>
> The pressure is one of the main reason Jim Bounds of Coop Mtrs consulted
> with us to come up with a system that would give same control performance
> in the rear suspension and have lower air pressure requirement.
> Tha is when we developed the Quadra Bag System that stabilizes the rear and
> run on 80-85 psi .
>
>> On Fri, Jul 7, 2017 at 10:25 AM, Emery Stora wrote:
>>
>> I would suggest raising the pressure a bit — perhaps 120 to 130 psi. This
>> will allow the bags to raise higher when leveling at a campsite and allow
>> the system to fill the bags slightly faster.
>> Most single OEM bag systems are around 90 psi for ride height but I think
>> I read once that the Harrison system needs more pressure to level the GMC.
>>
>> Emery Stora
>> 77 Kingsley
>> Frederick, CO
>>
>>> On Jul 7, 2017, at 10:33 AM, Joe williams wrote:
>>>
>>> Hello all, I just purchased my first GMC last week. 1978 Royale rear
>> twin and had a good trip back to Iowa from Wyoming (850 mi) with no
> issues.
>> So
>>> now I have been going over everything and have found a few things that
>> need attention and would appreciate any advice all you experts can give
> me.
>>> the first is I have a split cv boot on the drivers side, cv joint not
>> making any noise yet.
>>> Is it best to R & R it with a rebuilt axle or try to remove old boot and
>> replace with new boot.
>>> How time consuming and challenging is this job for a newbie?
>>> I see that some have used the split boot option with good and bad
>> results.any opinions on this?
>>> question #2 - It has a 4 bag rear suspension, Leigh Harrison 1999 (I
>> think) and the bag pressure is 110 psi on the driver side and 100 psi on
> the
>>> pass. side. does this sound normal for this system? it seems high to me,
>> and do you adjust the pressure at the air compressor? it's at 112 psi
>>>
>>> any info is greatly appreciated.
>>> thanks, Joe
>>>
>>> --
>>> jwilly
>>> 1978 Royale rear twin
>>>
>>> _______________________________________________
>>> GMCnet mailing list
>>> Unsubscribe or Change List Options:
>>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>>
>>
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>>
>
>
>
> --
> Jim Kanomata
> Applied/GMC, Newark,CA
> jimk@appliedairfilters.com
> http://www.appliedgmc.com
> 1-800-752-7502
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org

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Re: [GMCnet] new owner questions [message #320107 is a reply to message #320105] Fri, 07 July 2017 14:32 Go to previous messageGo to next message
Keith V is currently offline  Keith V   United States
Messages: 2337
Registered: March 2008
Location: Mounds View,MN
Karma: 0
Senior Member
I would bet a dollar of James' money that the limit Firestone is worried about is not the bags, but the internal valves. Especially since they really don't know what bags we are running.

That and they don't want to deal with managing a new sku for relatively low volumes. I'm sure if you put in an order for 1,000,000 you'd get your change.

________________________________
From: Gmclist on behalf of Emery Stora
Sent: Friday, July 7, 2017 2:24:41 PM
To: gmclist@list.gmcnet.org
Subject: Re: [GMCnet] new owner questions

Well, I've owned my motorhome for 36 years now and the air tank pressure has been set at 130 psi most of that time.
When traveling the bags are at approximately 90 psi.
When parking on a non-level campsite they have occasionally been pumped up as high as 130. No adverse effects. The original bags lasted for over thirty years.
You say you don't know why anyone would need over 100 psi. You might consider being able to level it better at a campsite as a reason.

By the way take a look at the GMC Maintenance manual X7725. Page 4A9-4A10 says the compressor will shut off at 120 psi. Also on page 4A10 in the paragraph PRESSURE SWITCH it says " The air pressure switch is designed to maintain air pressure in the wet tank between 100 and 120 psi. Switch activates at 100 psi and opens at 120 psi.
You might want to go back to Firestone and your manufacturer of the 72000 controller and point out to them that GM used 120 psi in the bags, NOT 100 psi.

Emery Stora
77 Kingsley
Frederick, CO

> On Jul 7, 2017, at 12:54 PM, James Hupy wrote:
>
> Anything over 100 psi is not advised by either Firestone or the
> manufacturer of the 72000 controller. They are both adamant in their
> opposition to higher pressures and limit their remote controllers to
> 100psi. I have been in contact with both of them and requested that they
> allow me to reprogram their systems to allow higher pressures. Both refused
> to do so. As Firestone makes the bags, they probably know the safe high
> limits. On single bag systems, you can add extenders to the bogie that
> lowers the pressure quite a bit, that will get the system to full
> extension. I don't know why you would need it to pump any more air than
> that. I suspect it might be the old horsepower thing."You can never have
> too much money, a girlfriend too pretty, or too much horsepower". Same
> applies to air pressure, I suspect.
> Jim Hupy
> Salem, Or
> 78 GMC ROYALE 403
>
> On Jul 7, 2017 11:38 AM, "Jim Kanomata" wrote:
>
> The pressure is one of the main reason Jim Bounds of Coop Mtrs consulted
> with us to come up with a system that would give same control performance
> in the rear suspension and have lower air pressure requirement.
> Tha is when we developed the Quadra Bag System that stabilizes the rear and
> run on 80-85 psi .
>
>> On Fri, Jul 7, 2017 at 10:25 AM, Emery Stora wrote:
>>
>> I would suggest raising the pressure a bit — perhaps 120 to 130 psi. This
>> will allow the bags to raise higher when leveling at a campsite and allow
>> the system to fill the bags slightly faster.
>> Most single OEM bag systems are around 90 psi for ride height but I think
>> I read once that the Harrison system needs more pressure to level the GMC.
>>
>> Emery Stora
>> 77 Kingsley
>> Frederick, CO
>>
>>> On Jul 7, 2017, at 10:33 AM, Joe williams wrote:
>>>
>>> Hello all, I just purchased my first GMC last week. 1978 Royale rear
>> twin and had a good trip back to Iowa from Wyoming (850 mi) with no
> issues.
>> So
>>> now I have been going over everything and have found a few things that
>> need attention and would appreciate any advice all you experts can give
> me.
>>> the first is I have a split cv boot on the drivers side, cv joint not
>> making any noise yet.
>>> Is it best to R & R it with a rebuilt axle or try to remove old boot and
>> replace with new boot.
>>> How time consuming and challenging is this job for a newbie?
>>> I see that some have used the split boot option with good and bad
>> results.any opinions on this?
>>> question #2 - It has a 4 bag rear suspension, Leigh Harrison 1999 (I
>> think) and the bag pressure is 110 psi on the driver side and 100 psi on
> the
>>> pass. side. does this sound normal for this system? it seems high to me,
>> and do you adjust the pressure at the air compressor? it's at 112 psi
>>>
>>> any info is greatly appreciated.
>>> thanks, Joe
>>>
>>> --
>>> jwilly
>>> 1978 Royale rear twin
>>>
>>> _______________________________________________
>>> GMCnet mailing list
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>>
>>
>> _______________________________________________
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>
>
>
> --
> Jim Kanomata
> Applied/GMC, Newark,CA
> jimk@appliedairfilters.com
> http://www.appliedgmc.com
> 1-800-752-7502
> _______________________________________________
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Keith Vasilakes
Mounds View. MN
75 ex Royale GMC
ask me about MicroLevel
Cell, 763-732-3419
My427v8@hotmail.com
Re: [GMCnet] new owner questions [message #320108 is a reply to message #320105] Fri, 07 July 2017 14:32 Go to previous messageGo to next message
James Hupy is currently offline  James Hupy   United States
Messages: 6806
Registered: May 2010
Karma: -62
Senior Member
Emery, you missed my point. I said, "When the suspension reaches the
maximum travel, then you can put 500 psi in there. It will not go any
higher." If you feel you want to run higher pressure than that, go with
your feelings. Just don't air them up when I am in the vicinity. I hate
sudden loud noises. (Grin)
Jim Hupy

On Jul 7, 2017 12:25 PM, "Emery Stora" wrote:

> Well, I've owned my motorhome for 36 years now and the air tank pressure
> has been set at 130 psi most of that time.
> When traveling the bags are at approximately 90 psi.
> When parking on a non-level campsite they have occasionally been pumped up
> as high as 130. No adverse effects. The original bags lasted for over
> thirty years.
> You say you don't know why anyone would need over 100 psi. You might
> consider being able to level it better at a campsite as a reason.
>
> By the way take a look at the GMC Maintenance manual X7725. Page 4A9-4A10
> says the compressor will shut off at 120 psi. Also on page 4A10 in the
> paragraph PRESSURE SWITCH it says " The air pressure switch is designed to
> maintain air pressure in the wet tank between 100 and 120 psi. Switch
> activates at 100 psi and opens at 120 psi.
> You might want to go back to Firestone and your manufacturer of the 72000
> controller and point out to them that GM used 120 psi in the bags, NOT 100
> psi.
>
> Emery Stora
> 77 Kingsley
> Frederick, CO
>
>> On Jul 7, 2017, at 12:54 PM, James Hupy wrote:
>>
>> Anything over 100 psi is not advised by either Firestone or the
>> manufacturer of the 72000 controller. They are both adamant in their
>> opposition to higher pressures and limit their remote controllers to
>> 100psi. I have been in contact with both of them and requested that they
>> allow me to reprogram their systems to allow higher pressures. Both
> refused
>> to do so. As Firestone makes the bags, they probably know the safe high
>> limits. On single bag systems, you can add extenders to the bogie that
>> lowers the pressure quite a bit, that will get the system to full
>> extension. I don't know why you would need it to pump any more air than
>> that. I suspect it might be the old horsepower thing."You can never have
>> too much money, a girlfriend too pretty, or too much horsepower". Same
>> applies to air pressure, I suspect.
>> Jim Hupy
>> Salem, Or
>> 78 GMC ROYALE 403
>>
>> On Jul 7, 2017 11:38 AM, "Jim Kanomata" wrote:
>>
>> The pressure is one of the main reason Jim Bounds of Coop Mtrs consulted
>> with us to come up with a system that would give same control performance
>> in the rear suspension and have lower air pressure requirement.
>> Tha is when we developed the Quadra Bag System that stabilizes the rear
> and
>> run on 80-85 psi .
>>
>>> On Fri, Jul 7, 2017 at 10:25 AM, Emery Stora
> wrote:
>>>
>>> I would suggest raising the pressure a bit — perhaps 120 to 130 psi.
> This
>>> will allow the bags to raise higher when leveling at a campsite and
> allow
>>> the system to fill the bags slightly faster.
>>> Most single OEM bag systems are around 90 psi for ride height but I
> think
>>> I read once that the Harrison system needs more pressure to level the
> GMC.
>>>
>>> Emery Stora
>>> 77 Kingsley
>>> Frederick, CO
>>>
>>>> On Jul 7, 2017, at 10:33 AM, Joe williams wrote:
>>>>
>>>> Hello all, I just purchased my first GMC last week. 1978 Royale rear
>>> twin and had a good trip back to Iowa from Wyoming (850 mi) with no
>> issues.
>>> So
>>>> now I have been going over everything and have found a few things that
>>> need attention and would appreciate any advice all you experts can give
>> me.
>>>> the first is I have a split cv boot on the drivers side, cv joint not
>>> making any noise yet.
>>>> Is it best to R & R it with a rebuilt axle or try to remove old boot
> and
>>> replace with new boot.
>>>> How time consuming and challenging is this job for a newbie?
>>>> I see that some have used the split boot option with good and bad
>>> results.any opinions on this?
>>>> question #2 - It has a 4 bag rear suspension, Leigh Harrison 1999 (I
>>> think) and the bag pressure is 110 psi on the driver side and 100 psi on
>> the
>>>> pass. side. does this sound normal for this system? it seems high to
> me,
>>> and do you adjust the pressure at the air compressor? it's at 112 psi
>>>>
>>>> any info is greatly appreciated.
>>>> thanks, Joe
>>>>
>>>> --
>>>> jwilly
>>>> 1978 Royale rear twin
>>>>
>>>> _______________________________________________
>>>> GMCnet mailing list
>>>> Unsubscribe or Change List Options:
>>>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>>>
>>>
>>> _______________________________________________
>>> GMCnet mailing list
>>> Unsubscribe or Change List Options:
>>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>>>
>>
>>
>>
>> --
>> Jim Kanomata
>> Applied/GMC, Newark,CA
>> jimk@appliedairfilters.com
>> http://www.appliedgmc.com
>> 1-800-752-7502
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>> _______________________________________________
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>
> _______________________________________________
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Re: [GMCnet] new owner questions [message #320109 is a reply to message #320108] Fri, 07 July 2017 14:39 Go to previous messageGo to next message
jimk is currently offline  jimk   United States
Messages: 6734
Registered: July 2006
Location: Belmont, CA
Karma: 9
Senior Member
Lee Harrison ran his Firestone bags over 120 psi and never heard of
problems. As long as it is around 5-6 years old, they seem to withstand the
higher pressure just like the tires.

On Fri, Jul 7, 2017 at 12:32 PM, James Hupy wrote:

> Emery, you missed my point. I said, "When the suspension reaches the
> maximum travel, then you can put 500 psi in there. It will not go any
> higher." If you feel you want to run higher pressure than that, go with
> your feelings. Just don't air them up when I am in the vicinity. I hate
> sudden loud noises. (Grin)
> Jim Hupy
>
> On Jul 7, 2017 12:25 PM, "Emery Stora" wrote:
>
>> Well, I've owned my motorhome for 36 years now and the air tank pressure
>> has been set at 130 psi most of that time.
>> When traveling the bags are at approximately 90 psi.
>> When parking on a non-level campsite they have occasionally been pumped
> up
>> as high as 130. No adverse effects. The original bags lasted for over
>> thirty years.
>> You say you don't know why anyone would need over 100 psi. You might
>> consider being able to level it better at a campsite as a reason.
>>
>> By the way take a look at the GMC Maintenance manual X7725. Page 4A9-4A10
>> says the compressor will shut off at 120 psi. Also on page 4A10 in the
>> paragraph PRESSURE SWITCH it says " The air pressure switch is designed
> to
>> maintain air pressure in the wet tank between 100 and 120 psi. Switch
>> activates at 100 psi and opens at 120 psi.
>> You might want to go back to Firestone and your manufacturer of the 72000
>> controller and point out to them that GM used 120 psi in the bags, NOT
> 100
>> psi.
>>
>> Emery Stora
>> 77 Kingsley
>> Frederick, CO
>>
>>> On Jul 7, 2017, at 12:54 PM, James Hupy wrote:
>>>
>>> Anything over 100 psi is not advised by either Firestone or the
>>> manufacturer of the 72000 controller. They are both adamant in their
>>> opposition to higher pressures and limit their remote controllers to
>>> 100psi. I have been in contact with both of them and requested that
> they
>>> allow me to reprogram their systems to allow higher pressures. Both
>> refused
>>> to do so. As Firestone makes the bags, they probably know the safe high
>>> limits. On single bag systems, you can add extenders to the bogie that
>>> lowers the pressure quite a bit, that will get the system to full
>>> extension. I don't know why you would need it to pump any more air than
>>> that. I suspect it might be the old horsepower thing."You can never
> have
>>> too much money, a girlfriend too pretty, or too much horsepower". Same
>>> applies to air pressure, I suspect.
>>> Jim Hupy
>>> Salem, Or
>>> 78 GMC ROYALE 403
>>>
>>> On Jul 7, 2017 11:38 AM, "Jim Kanomata" wrote:
>>>
>>> The pressure is one of the main reason Jim Bounds of Coop Mtrs
> consulted
>>> with us to come up with a system that would give same control
> performance
>>> in the rear suspension and have lower air pressure requirement.
>>> Tha is when we developed the Quadra Bag System that stabilizes the rear
>> and
>>> run on 80-85 psi .
>>>
>>>> On Fri, Jul 7, 2017 at 10:25 AM, Emery Stora
>> wrote:
>>>>
>>>> I would suggest raising the pressure a bit — perhaps 120 to 130 psi.
>> This
>>>> will allow the bags to raise higher when leveling at a campsite and
>> allow
>>>> the system to fill the bags slightly faster.
>>>> Most single OEM bag systems are around 90 psi for ride height but I
>> think
>>>> I read once that the Harrison system needs more pressure to level the
>> GMC.
>>>>
>>>> Emery Stora
>>>> 77 Kingsley
>>>> Frederick, CO
>>>>
>>>> > On Jul 7, 2017, at 10:33 AM, Joe williams
> wrote:
>>>> >
>>>> > Hello all, I just purchased my first GMC last week. 1978 Royale rear
>>>> twin and had a good trip back to Iowa from Wyoming (850 mi) with no
>>> issues.
>>>> So
>>>> > now I have been going over everything and have found a few things
> that
>>>> need attention and would appreciate any advice all you experts can
> give
>>> me.
>>>> > the first is I have a split cv boot on the drivers side, cv joint not
>>>> making any noise yet.
>>>> > Is it best to R & R it with a rebuilt axle or try to remove old boot
>> and
>>>> replace with new boot.
>>>> > How time consuming and challenging is this job for a newbie?
>>>> > I see that some have used the split boot option with good and bad
>>>> results.any opinions on this?
>>>> > question #2 - It has a 4 bag rear suspension, Leigh Harrison 1999 (I
>>>> think) and the bag pressure is 110 psi on the driver side and 100 psi
> on
>>> the
>>>> > pass. side. does this sound normal for this system? it seems high to
>> me,
>>>> and do you adjust the pressure at the air compressor? it's at 112 psi
>>>> >
>>>> > any info is greatly appreciated.
>>>> > thanks, Joe
>>>> >
>>>> > --
>>>> > jwilly
>>>> > 1978 Royale rear twin
>>>> >
>>>> > _______________________________________________
>>>> > GMCnet mailing list
>>>> > Unsubscribe or Change List Options:
>>>> > http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>>>>
>>>>
>>>> _______________________________________________
>>>> GMCnet mailing list
>>>> Unsubscribe or Change List Options:
>>>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>>>>
>>>
>>>
>>>
>>> --
>>> Jim Kanomata
>>> Applied/GMC, Newark,CA
>>> jimk@appliedairfilters.com
>>> http://www.appliedgmc.com
>>> 1-800-752-7502
>>> _______________________________________________
>>> GMCnet mailing list
>>> Unsubscribe or Change List Options:
>>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>>> _______________________________________________
>>> GMCnet mailing list
>>> Unsubscribe or Change List Options:
>>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>>
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>>
> _______________________________________________
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--
Jim Kanomata
Applied/GMC, Newark,CA
jimk@appliedairfilters.com
http://www.appliedgmc.com
1-800-752-7502
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Jim Kanomata
Applied/GMC
jimk@appliedairfilters.com
www.appliedgmc.com
1-800-752-7502
Re: [GMCnet] new owner questions [message #320112 is a reply to message #320092] Fri, 07 July 2017 15:55 Go to previous messageGo to next message
Mr ERFisher is currently offline  Mr ERFisher   United States
Messages: 7117
Registered: August 2005
Karma: 2
Senior Member
On Fri, Jul 7, 2017 at 9:34 AM Joe williams wrote:

> Hello all, I just purchased my first GMC last week. 1978 Royale rear twin
> and had a good trip back to Iowa from Wyoming (850 mi) with no issues. So
> now I have been going over everything and have found a few things that
> need attention and would appreciate any advice all you experts can give me.
> the first is I have a split cv boot on the drivers side, cv joint not
> making any noise yet.
> Is it best to R & R it with a rebuilt axle or try to remove old boot and
> replace with new boot.
> How time consuming and challenging is this job for a newbie?


Read here
http://gmcmotorhome.info/front.html#boot


> I see that some have used the split boot option with good and bad
> results.any opinions on this?
> question #2 - It has a 4 bag rear suspension, Leigh Harrison 1999 (I
> think) and the bag pressure is 110 psi on the driver side and 100 psi on the
> pass. side. does this sound normal for this system? it seems high to me,
> and do you adjust the pressure at the air compressor? it's at 112 psi
>
> any info is greatly appreciated.
> thanks, Joe
>
> --
> jwilly
> 1978 Royale rear twin
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
--
Gene Fisher -- 74-23,77PB/ore/ca
“Give a man a fish; you have fed him for today --- give him a URL and
-------
http://gmcmotorhome.info/
Alternator Protection Cable
http://gmcmotorhome.info/APC.html
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Re: [GMCnet] new owner questions [message #320115 is a reply to message #320112] Fri, 07 July 2017 16:22 Go to previous messageGo to next message
tphipps is currently offline  tphipps   United States
Messages: 3005
Registered: August 2004
Location: Spanish Fort, AL
Karma: 9
Senior Member
1. Pressure in your Leigh Harrison bags is very close to the pressure in my Leigh Harrison bag system. Measure your ride height to be sure that the air pressure is correct for your coach. This system has been on my 1975 Avion 26' for 4 years without any problems. Just check your ride height before you leave home.
2. I have 2 of the Dorman split bags on my outer CV joints. At least one has been in place for 3 years. A very fast and easy replacement. Having wrestled with the Dorman 'Universal boot' and Dorman split boot, the split boot fits better around the big edge of the outer CV joint. I carry one as a spare. I, and many others, have used the split boot on the CV joints of many VW and Porsche products. Lots of years on those vehicles.
3. I believe that your air pressure switch is mal-adjusted. The switch should turn on the air compressor at 100psi and turn off at 120 psi. There is a user adjustable screw inside the cover to move the air range.

Enjoy your new toy. Many happy miles. Get a copy of the "Black List," and keep it in the coach.
Tom, MS II


2012 Phoenix Cruiser model 2552 KA4CSG
Re: [GMCnet] new owner questions [message #320123 is a reply to message #320092] Fri, 07 July 2017 18:10 Go to previous messageGo to next message
Ken Henderson is currently offline  Ken Henderson   United States
Messages: 8726
Registered: March 2004
Location: Americus, GA
Karma: 9
Senior Member
Welcome aboard, Joe. You've found the right place for technical support.
You'll get a lot of advice, some good, some bad, but at least you'll have
information as a basis to make your own decisions.

I personally have never used a split boot, nor do I think I would. But, if
I did, the one inviolable rule I'd follow, as I do with regular boots, is
to be sure the surface where the large end of the CV joint, where boot
fits, is absolutely clean -- NO grease residue. Same for the inside of the
boot there. That ensures that when you install the clamp, there' s a good
seal, with no boot sliding.

It's also important, IMHO, to use only double-wrap clamps. At one time
NAPA sold those clamps pre-cut; whether they still do I don't know. I buy
the "buckles" and 1/4" Band-It from McMaster-Carr and cut my own -- 37" for
the large end clamp. The small end clamp is not needed, but if it makes
you feel better, re-use a large end Band-It clamp (IF you have one).

I've had the Harrison 4-bag since 1998, with never a problem. I'm still
running the original bags after 100,000+ miles. IIRC, Leigh's
documentations specified 130 psi max. Your settings sound very
reasonable. In case you haven't heard, that system does reduce the maximum
suspension travel vs the OEM system, by about 3", IIRC.

Most Harrison systems I've seen installed follow Leigh's instructions and
mount the manifolds, with their shutoff valves and pressure gauges in the
wheel wells, often on the bag support pedestal. That, IMHO, is a BAD idea,
especially if you have the "fender skirts". Why? Because if the bags are
down, it will be impossible to get to the manifold to add air without
jacking the coach up. I moved my manifolds into the rear compartments,
right at the top of the openings where they're out of the way but easily
accessible. Possibly an added benefit is that if I ever over-inflate a bag
to failure, I won't be beside it.

JWID,

Ken H.
Americus, GA
'76 X-Birchaven w/Cad500/Howell EFI & EBL,
Manny Brakes & 1-Ton, etc., etc., etc.
www.gmcwipersetc.com

On Fri, Jul 7, 2017 at 12:33 PM, Joe williams wrote:

> ​...
>
> the first is I have a split cv boot on the drivers side, cv joint not
> making any noise yet.
> Is it best to R & R it with a rebuilt axle or try to remove old boot and
> replace with new boot.
> How time consuming and challenging is this job for a newbie?
> I see that some have used the split boot option with good and bad
> results.any opinions on this?
>


> question #2 - It has a 4 bag rear suspension, Leigh Harrison 1999 (I
> think) and the bag pressure is 110 psi on the driver side and 100 psi on the
> pass. side. does this sound normal for this system? it seems high to me,
> and do you adjust the pressure at the air compressor? it's at 112 psi
>
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Ken Henderson
Americus, GA
www.gmcwipersetc.com
Large Wiring Diagrams
76 X-Birchaven
76 X-Palm Beach
Re: [GMCnet] new owner questions [message #320126 is a reply to message #320102] Fri, 07 July 2017 18:45 Go to previous messageGo to next message
Jeanette is currently offline  Jeanette   United States
Messages: 118
Registered: May 2013
Karma: 0
Senior Member
Kim Weeks administrator for GMC Motorhomes International is in Indanola Iowa for summer. Lots of info there. Gmcmi.com

Sent from my iPhone

> On Jul 7, 2017, at 1:54 PM, James Hupy wrote:
>
> Anything over 100 psi is not advised by either Firestone or the
> manufacturer of the 72000 controller. They are both adamant in their
> opposition to higher pressures and limit their remote controllers to
> 100psi. I have been in contact with both of them and requested that they
> allow me to reprogram their systems to allow higher pressures. Both refused
> to do so. As Firestone makes the bags, they probably know the safe high
> limits. On single bag systems, you can add extenders to the bogie that
> lowers the pressure quite a bit, that will get the system to full
> extension. I don't know why you would need it to pump any more air than
> that. I suspect it might be the old horsepower thing."You can never have
> too much money, a girlfriend too pretty, or too much horsepower". Same
> applies to air pressure, I suspect.
> Jim Hupy
> Salem, Or
> 78 GMC ROYALE 403
>
> On Jul 7, 2017 11:38 AM, "Jim Kanomata" wrote:
>
> The pressure is one of the main reason Jim Bounds of Coop Mtrs consulted
> with us to come up with a system that would give same control performance
> in the rear suspension and have lower air pressure requirement.
> Tha is when we developed the Quadra Bag System that stabilizes the rear and
> run on 80-85 psi .
>
>> On Fri, Jul 7, 2017 at 10:25 AM, Emery Stora wrote:
>>
>> I would suggest raising the pressure a bit — perhaps 120 to 130 psi. This
>> will allow the bags to raise higher when leveling at a campsite and allow
>> the system to fill the bags slightly faster.
>> Most single OEM bag systems are around 90 psi for ride height but I think
>> I read once that the Harrison system needs more pressure to level the GMC.
>>
>> Emery Stora
>> 77 Kingsley
>> Frederick, CO
>>
>>> On Jul 7, 2017, at 10:33 AM, Joe williams wrote:
>>>
>>> Hello all, I just purchased my first GMC last week. 1978 Royale rear
>> twin and had a good trip back to Iowa from Wyoming (850 mi) with no
> issues.
>> So
>>> now I have been going over everything and have found a few things that
>> need attention and would appreciate any advice all you experts can give
> me.
>>> the first is I have a split cv boot on the drivers side, cv joint not
>> making any noise yet.
>>> Is it best to R & R it with a rebuilt axle or try to remove old boot and
>> replace with new boot.
>>> How time consuming and challenging is this job for a newbie?
>>> I see that some have used the split boot option with good and bad
>> results.any opinions on this?
>>> question #2 - It has a 4 bag rear suspension, Leigh Harrison 1999 (I
>> think) and the bag pressure is 110 psi on the driver side and 100 psi on
> the
>>> pass. side. does this sound normal for this system? it seems high to me,
>> and do you adjust the pressure at the air compressor? it's at 112 psi
>>>
>>> any info is greatly appreciated.
>>> thanks, Joe
>>>
>>> --
>>> jwilly
>>> 1978 Royale rear twin
>>>
>>> _______________________________________________
>>> GMCnet mailing list
>>> Unsubscribe or Change List Options:
>>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>>
>>
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>>
>
>
>
> --
> Jim Kanomata
> Applied/GMC, Newark,CA
> jimk@appliedairfilters.com
> http://www.appliedgmc.com
> 1-800-752-7502
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
> _______________________________________________
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> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org

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Re: [GMCnet] new owner questions [message #320127 is a reply to message #320092] Fri, 07 July 2017 18:40 Go to previous messageGo to next message
Jeanette is currently offline  Jeanette   United States
Messages: 118
Registered: May 2013
Karma: 0
Senior Member
Midwest Classics group is having a rally at Duluth MN starting Sunday. Many have Royales there. It would be worth your while to get there by car or motorhome to see n ask questions of lots of good people. If you want info google Midwest Classics GMC.

Sent from my iPhone

> On Jul 7, 2017, at 11:33 AM, Joe williams wrote:
>
> Hello all, I just purchased my first GMC last week. 1978 Royale rear twin and had a good trip back to Iowa from Wyoming (850 mi) with no issues. So
> now I have been going over everything and have found a few things that need attention and would appreciate any advice all you experts can give me.
> the first is I have a split cv boot on the drivers side, cv joint not making any noise yet.
> Is it best to R & R it with a rebuilt axle or try to remove old boot and replace with new boot.
> How time consuming and challenging is this job for a newbie?
> I see that some have used the split boot option with good and bad results.any opinions on this?
> question #2 - It has a 4 bag rear suspension, Leigh Harrison 1999 (I think) and the bag pressure is 110 psi on the driver side and 100 psi on the
> pass. side. does this sound normal for this system? it seems high to me, and do you adjust the pressure at the air compressor? it's at 112 psi
>
> any info is greatly appreciated.
> thanks, Joe
>
> --
> jwilly
> 1978 Royale rear twin
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org

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Re: [GMCnet] new owner questions [message #320133 is a reply to message #320108] Fri, 07 July 2017 20:30 Go to previous messageGo to next message
Emery Stora is currently offline  Emery Stora   United States
Messages: 959
Registered: January 2011
Karma: 4
Senior Member
I am thinking perhaps you are missing my point. You said that you don’t know why anyone would want more than 100 psi.
I was pointing out that GM used a cut off pressure of 120 psi over 40 years ago.
They are not going to blow up at 120 or 130 psi.

Emery Stora

> On Jul 7, 2017, at 1:32 PM, James Hupy wrote:
>
> Emery, you missed my point. I said, "When the suspension reaches the
> maximum travel, then you can put 500 psi in there. It will not go any
> higher." If you feel you want to run higher pressure than that, go with
> your feelings. Just don't air them up when I am in the vicinity. I hate
> sudden loud noises. (Grin)
> Jim Hupy
>
> On Jul 7, 2017 12:25 PM, "Emery Stora" wrote:
>
>> Well, I've owned my motorhome for 36 years now and the air tank pressure
>> has been set at 130 psi most of that time.
>> When traveling the bags are at approximately 90 psi.
>> When parking on a non-level campsite they have occasionally been pumped up
>> as high as 130. No adverse effects. The original bags lasted for over
>> thirty years.
>> You say you don't know why anyone would need over 100 psi. You might
>> consider being able to level it better at a campsite as a reason.
>>
>> By the way take a look at the GMC Maintenance manual X7725. Page 4A9-4A10
>> says the compressor will shut off at 120 psi. Also on page 4A10 in the
>> paragraph PRESSURE SWITCH it says " The air pressure switch is designed to
>> maintain air pressure in the wet tank between 100 and 120 psi. Switch
>> activates at 100 psi and opens at 120 psi.
>> You might want to go back to Firestone and your manufacturer of the 72000
>> controller and point out to them that GM used 120 psi in the bags, NOT 100
>> psi.
>>
>> Emery Stora
>> 77 Kingsley
>> Frederick, CO
>>
>>> On Jul 7, 2017, at 12:54 PM, James Hupy wrote:
>>>
>>> Anything over 100 psi is not advised by either Firestone or the
>>> manufacturer of the 72000 controller. They are both adamant in their
>>> opposition to higher pressures and limit their remote controllers to
>>> 100psi. I have been in contact with both of them and requested that they
>>> allow me to reprogram their systems to allow higher pressures. Both
>> refused
>>> to do so. As Firestone makes the bags, they probably know the safe high
>>> limits. On single bag systems, you can add extenders to the bogie that
>>> lowers the pressure quite a bit, that will get the system to full
>>> extension. I don't know why you would need it to pump any more air than
>>> that. I suspect it might be the old horsepower thing."You can never have
>>> too much money, a girlfriend too pretty, or too much horsepower". Same
>>> applies to air pressure, I suspect.
>>> Jim Hupy
>>> Salem, Or
>>> 78 GMC ROYALE 403
>>>
>>> On Jul 7, 2017 11:38 AM, "Jim Kanomata" wrote:
>>>
>>> The pressure is one of the main reason Jim Bounds of Coop Mtrs consulted
>>> with us to come up with a system that would give same control performance
>>> in the rear suspension and have lower air pressure requirement.
>>> Tha is when we developed the Quadra Bag System that stabilizes the rear
>> and
>>> run on 80-85 psi .
>>>
>>>> On Fri, Jul 7, 2017 at 10:25 AM, Emery Stora
>> wrote:
>>>>
>>>> I would suggest raising the pressure a bit — perhaps 120 to 130 psi.
>> This
>>>> will allow the bags to raise higher when leveling at a campsite and
>> allow
>>>> the system to fill the bags slightly faster.
>>>> Most single OEM bag systems are around 90 psi for ride height but I
>> think
>>>> I read once that the Harrison system needs more pressure to level the
>> GMC.
>>>>
>>>> Emery Stora
>>>> 77 Kingsley
>>>> Frederick, CO
>>>>
>>>> > On Jul 7, 2017, at 10:33 AM, Joe williams wrote:
>>>> >
>>>> > Hello all, I just purchased my first GMC last week. 1978 Royale rear
>>>> twin and had a good trip back to Iowa from Wyoming (850 mi) with no
>>> issues.
>>>> So
>>>> > now I have been going over everything and have found a few things that
>>>> need attention and would appreciate any advice all you experts can give
>>> me.
>>>> > the first is I have a split cv boot on the drivers side, cv joint not
>>>> making any noise yet.
>>>> > Is it best to R & R it with a rebuilt axle or try to remove old boot
>> and
>>>> replace with new boot.
>>>> > How time consuming and challenging is this job for a newbie?
>>>> > I see that some have used the split boot option with good and bad
>>>> results.any opinions on this?
>>>> > question #2 - It has a 4 bag rear suspension, Leigh Harrison 1999 (I
>>>> think) and the bag pressure is 110 psi on the driver side and 100 psi on
>>> the
>>>> > pass. side. does this sound normal for this system? it seems high to
>> me,
>>>> and do you adjust the pressure at the air compressor? it's at 112 psi
>>>> >
>>>> > any info is greatly appreciated.
>>>> > thanks, Joe
>>>> >
>>>> > --
>>>> > jwilly
>>>> > 1978 Royale rear twin
>>>> >
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>>>
>>>
>>>
>>> --
>>> Jim Kanomata
>>> Applied/GMC, Newark,CA
>>> jimk@appliedairfilters.com
>>> http://www.appliedgmc.com
>>> 1-800-752-7502
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Re: new owner questions [message #320146 is a reply to message #320092] Sat, 08 July 2017 08:20 Go to previous messageGo to next message
joewilly is currently offline  joewilly   United States
Messages: 40
Registered: April 2016
Location: Victor,Ia
Karma: -1
Member
WOW! Thanks to all for your advice/opinions, didn't think I would get such a great response, I think I'll just go with a split boot for now since it sounds the easiest/fastest and I can get her back on the road. if it doesn't hold up I can redo it later.

Ken, what is a double wrap clamp? do I need to get a special tool to use them?

Tom, I found on one of your old posts that you used Dorman 03609 ,did you use the clamps that came with it?

and do you know what bag is used on the Harrison system and where I can get a spare to keep in the coach.

Thanks again to all, so great to be able to get such good advice so quickly and look forward to meeting some of you at a rally soon.

Joe



Joe Williams 1978 Royale rear twin
Re: [GMCnet] new owner questions [message #320149 is a reply to message #320146] Sat, 08 July 2017 09:00 Go to previous messageGo to previous message
USAussie is currently offline  USAussie   United States
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
Senior Member
Joe,

Firestone P/N W01-358-3400 - with bellows #224C
Compressed height: 3.00 inches
Extended height: 8.91 inches
Range: 5.91 inches

http://firestoneip.com/-/media/www/global/files/documents/Data%20Sheets/W013583400.pdf

http://www.sdtrucksprings.com/index.php?main_page=product_info&products_id=8195

Regards,
Rob M.
Sydney, Australia
AUS '75 Avion - The Blue Streak TZE365V100428
USA '75 Avion - Double Trouble TZE365V100426
USA '77 Kingsley - TZE 267V100808


-----Original Message-----
From: Gmclist [mailto:gmclist-bounces@list.gmcnet.org] On Behalf Of Joe williams
Sent: Saturday, July 8, 2017 11:20 PM
To: gmclist@list.gmcnet.org
Subject: Re: [GMCnet] new owner questions

WOW! Thanks to all for your advice/opinions, didn't think I would get such a great response, I think I'll just go with a split boot
for now since it sounds the easiest/fastest and I can get her back on the road. if it doesn't hold up I can redo it later.

Ken, what is a double wrap clamp? do I need to get a special tool to use them?

Tom, I found on one of your old posts that you used Dorman 03609 ,did you use the clamps that came with it?

and do you know what bag is used on the Harrison system and where I can get a spare to keep in the coach.

Thanks again to all, so great to be able to get such good advice so quickly and look forward to meeting some of you at a rally soon.

Joe


--
Joe Williams
1978 Royale rear twin

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Regards, Rob M. (USAussie) The Pedantic Mechanic Sydney, Australia '75 Avion - AUS - The Blue Streak TZE365V100428 '75 Avion - USA - Double Trouble TZE365V100426
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