Home » Public Forums » GMCnet » Air suspension and leveling system (Air suspension will not raise on a 1973 gmc motor home)
| Air suspension and leveling system [message #319213] |
Sun, 18 June 2017 09:46  |
Nathan
Messages: 1
Registered: June 2017
Karma: 0
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Junior Member |
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Hello everyone, this is my first post on this forum so please correct me if this is the wrong place to post. Thanks!
I recently bought a 1973 gmc motor home with the 455 olds motor. It had not run since 1994, so I changed all fluids and the battery and started it up. However, the air suspension would not raise the back of the motor home. So I drove it home at about 10mph. The air suspension is the first thing I would like to fix, but I am not sure where to start. Any advice would be greatly appreciated. (I tried to use the leveling controls to raise the back, but that did not chance anything)
Thanks
Nathan
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| Re: [GMCnet] Air suspension and leveling system [message #319218 is a reply to message #319214] |
Sun, 18 June 2017 10:11  |
James Hupy
Messages: 6806
Registered: May 2010
Karma: -62
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Senior Member |
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RTFM. if you have one. If not, find one and spend some time reading it. You
will get the exact information, without prejudice or imbellishments or
outright WRONG INFORMATION. Then you will be prepared for the onslaught of
information you are about to receive. 73's and 74's are unique and a bit
quirky, but when all is well, they do work.
Jim Hupy
Salem, Or
78 GMC ROYALE 403
On Jun 18, 2017 8:01 AM, "Wally Anderson" wrote:
> Nathan wrote on Sun, 18 June 2017 09:46
>> Hello everyone, this is my first post on this forum so please correct me
> if this is the wrong place to post. Thanks!
>> I recently bought a 1973 gmc motor home with the 455 olds motor. It had
> not run since 1994, so I changed all fluids and the battery and started it
>> up. However, the air suspension would not raise the back of the motor
> home. So I drove it home at about 10mph. The air suspension is the first
> thing
>> I would like to fix, but I am not sure where to start. Any advice would
> be greatly appreciated. (I tried to use the leveling controls to raise the
>> back, but that did not chance anything)
>> Thanks
>> Nathan
>
> Welcome aboard Nathan!
> Here are some links describing our power level system.
> http://www.gmceast.com/technical/Denney_Power_Level_System.pdf
> http://www.gmceast.com/technical/Denney_Power_Level_System.pdf
> and
> http://www.bdub.net/GMC_Power_Level_Air_Suspension_Systems.pdf
> http://www.bdub.net/GMC_Power_Level_Air_Suspension_Systems.pdf
> These should get you going. Does the compressor run and do you have
> pressure in the tank?
> --
> Wally Anderson
> Omaha NE
> 75 Glenbrook
> Megasquirt III injection
> Bob Stone hydroBOOOOST
> Manny reaction arm system
> Branscombe Kelsey Hayes park brake
> http://wallyandsue.blogspot.com/
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
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| Re: Air suspension and leveling system [message #319219 is a reply to message #319213] |
Sun, 18 June 2017 10:56 |
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Matt Colie
Messages: 8547
Registered: March 2007
Location: S.E. Michigan
Karma: 7
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Senior Member |
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Nathan wrote on Sun, 18 June 2017 10:46Hello everyone, this is my first post on this forum so please correct me if this is the wrong place to post. Thanks!
I recently bought a 1973 gmc motor home with the 455 olds motor. It had not run since 1994, so I changed all fluids and the battery and started it up. However, the air suspension would not raise the back of the motor home. So I drove it home at about 10mph. The air suspension is the first thing I would like to fix, but I am not sure where to start. Any advice would be greatly appreciated. (I tried to use the leveling controls to raise the back, but that did not chance anything)
Thanks
Nathan
Nathan,
Welcome to the group, family, cult, asylum....
This is the RIGHT place to post questions. If you scroll down, you will find that I still am, and I have owned our coach for 12 years and 60K+ miles.
Finding your way here was the very best thing that you could do. This is an uncommon community of owners that want to see you enjoy what your coach can do for you as much as we all know it can. Just be aware that this is a 44 year old "truck" (it isn't a truck chassis) with a 44 year old cabin on it that has been though a multi-decade earthquake. It will require maintenance, but if you keep up with that maintenance, she can be reliable. In fact, she can be as reliable as anything just off the dealer lot.
Now, about the air suspension. It you digest the two papers that Wally pointed you to, you will learn virtually all you need to know to make it work correctly. Until you have it at least nearly functional, do not buy any parts you do not need. The basic system's weak point (imho) is the compressor. The second, and you have to have a compressor to find it is the body joint in the control valves. This joint is made with a cork/composite gasket that is wrong for the application. (I have a fix that works if the gasket is not damaged.) When you get pressure in the system and have the valves pulled out, check that joint early in the game. When you learn enough to frame a question, bring it back here. You will get a good answer.
If you have not downloaded the documentation from Bdub's, this would be a good time. You particularly need manual X7425. Your coach is a 73-23 and there is a lot about it that was changed for later (that are covered in the X7525 manual). Believe me when I tell you this (read my sigfile).
Well, here is a part that I like a lot. You have just become a member of an amazing community. These people will be an unbelievable resource. To aid this, please build a useful sigfile. Go to <Control Panel/Account Settings> and scroll down to the signiture box. Fill in your name, a bit about the coach, and a geographic reference. This is all needed so, we know who we talked to, what is special about the coach and if you are in striking range for someone that wants to help.
This supportive and helping community so like that of the watermen of my world that I have taken to welcoming any that arrive here much as a new owner or vessel is welcomed there just because I feel it is fitting. So,
May the Good Lord bless this coach and all those that set forth within her.
Welcome Nathan
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
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| Re: Air suspension and leveling system [message #319223 is a reply to message #319219] |
Sun, 18 June 2017 11:33 |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
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Senior Member |
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Before you get in to it too far make sure that someone did not install aftermarket shutoff valves on the air bags. These were not GM installed and will not be mentioned in any manual. After that, find out if he compressor is running and if there is any pressure in the tank.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
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| Re: [GMCnet] Air suspension and leveling system [message #319224 is a reply to message #319219] |
Sun, 18 June 2017 11:32 |
Burt and Faye curtis
Messages: 256
Registered: June 2012
Karma: 4
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Senior Member |
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Friend had a 73 in which the compressor does not shut off. I am suspecting
that the pressure switch either is not hooked up or is not working. Her
coach is using the Dana compressor which is not the one shown in the early
73 workshop manual and is up in front of driver's wheel area.
Would anyone know where to start looking for the pressure switch? Oh, there
seems to be no air leaks, so don't believe that is why it keeps running.
Nice article from Eastern States, but like the workshop manual, it doesn't
address a compressor that just won't stop.
Thanks in advance.
Fay Curtis
76 Glenbrook that had same problem, but has electrolevel 1 system
Kneeland, Ca
On Sunday, June 18, 2017, Matt Colie wrote:
> Nathan wrote on Sun, 18 June 2017 10:46
>> Hello everyone, this is my first post on this forum so please correct me
> if this is the wrong place to post. Thanks!
>> I recently bought a 1973 gmc motor home with the 455 olds motor. It had
> not run since 1994, so I changed all fluids and the battery and started it
>> up. However, the air suspension would not raise the back of the motor
> home. So I drove it home at about 10mph. The air suspension is the first
> thing
>> I would like to fix, but I am not sure where to start. Any advice would
> be greatly appreciated. (I tried to use the leveling controls to raise the
>> back, but that did not chance anything)
>> Thanks
>> Nathan
>
> Nathan,
>
> Welcome to the group, family, cult, asylum....
>
> This is the RIGHT place to post questions. If you scroll down, you will
> find that I still am, and I have owned our coach for 12 years and 60K+
> miles.
>
> Finding your way here was the very best thing that you could do. This is
> an uncommon community of owners that want to see you enjoy what your coach
> can do for you as much as we all know it can. Just be aware that this is
> a 44 year old "truck" (it isn't a truck chassis) with a 44 year old cabin on
> it that has been though a multi-decade earthquake. It will require
> maintenance, but if you keep up with that maintenance, she can be
> reliable. In
> fact, she can be as reliable as anything just off the dealer lot.
>
> Now, about the air suspension. It you digest the two papers that Wally
> pointed you to, you will learn virtually all you need to know to make it
> work
> correctly. Until you have it at least nearly functional, do not buy any
> parts you do not need. The basic system's weak point (imho) is the
> compressor. The second, and you have to have a compressor to find it is
> the body joint in the control valves. This joint is made with a
> cork/composite gasket that is wrong for the application. (I have a fix
> that works if the gasket is not damaged.) When you get pressure in the
> system
> and have the valves pulled out, check that joint early in the game. When
> you learn enough to frame a question, bring it back here. You will get a
> good answer.
>
> If you have not downloaded the documentation from Bdub's, this would be a
> good time. You particularly need manual X7425. Your coach is a 73-23 and
> there is a lot about it that was changed for later (that are covered in
> the X7525 manual). Believe me when I tell you this (read my sigfile).
>
> Well, here is a part that I like a lot. You have just become a member of
> an amazing community. These people will be an unbelievable resource. To
> aid this, please build a useful sigfile. Go to Settings> and scroll down to the signiture box. Fill in your name, a bit
> about
> the coach, and a geographic reference. This is all needed so, we know who
> we talked to, what is special about the coach and if you are in striking
> range for someone that wants to help.
>
> This supportive and helping community so like that of the watermen of my
> world that I have taken to welcoming any that arrive here much as a new
> owner
> or vessel is welcomed there just because I feel it is fitting. So,
>
> May the Good Lord bless this coach and all those that set forth within her.
>
> Welcome Nathan
>
> Matt
>
> --
> Matt & Mary Colie - '73 Glacier 23 - Members GMCMI, GMCGL, GMCES
> Still Loving OE Rear Drum Brakes with Applied Control Arms
> SE Michigan - Twixt A2 and Detroit
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
_______________________________________________
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| Re: Air suspension and leveling system [message #319226 is a reply to message #319213] |
Sun, 18 June 2017 11:45 |
Steve
Messages: 506
Registered: September 2013
Location: East Greenville, Pa
Karma: 1
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Senior Member |
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Nathan,
A big GMC welcome to you. You have found the right place for good technical assistance. Between the manuals and the experts here you should be able to troubleshoot all systems. For the rear air suspension, many have installed manual shut off valves near the air bags, with schrader air valves so you can air the bags up with any standard air compressor or air hose at a service station. That would at least test the ability for the bags to hold air and allow you to travel or move the coach while you troubleshoot the rest of the system. check near the air bags to see if you already have them, if not they are available on-line at Applied GMC.
1978 GMC Royal
Eastern Pennslyvania
1968 Chevrolet C20 396 Camper Special
1969 Chevrolet C20 Camper Special
1985 Buick Electra Park Avenue
1992 Camaro 25th Anniversary Heretage Edition Black
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| Re: [GMCnet] Air suspension and leveling system [message #319228 is a reply to message #319224] |
Sun, 18 June 2017 11:46 |
Gary Worobec
Messages: 867
Registered: May 2005
Karma: -1
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Senior Member |
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On my 73 the pressure switch is viewable on the drivers side as you open the front drivers side hatch. Probably about a foot in.
> On Jun 18, 2017, at 9:32 AM, Burt and Faye curtis wrote:
>
> Friend had a 73 in which the compressor does not shut off. I am suspecting
> that the pressure switch either is not hooked up or is not working. Her
> coach is using the Dana compressor which is not the one shown in the early
> 73 workshop manual and is up in front of driver's wheel area.
> Would anyone know where to start looking for the pressure switch? Oh, there
> seems to be no air leaks, so don't believe that is why it keeps running.
> Nice article from Eastern States, but like the workshop manual, it doesn't
> address a compressor that just won't stop.
>
> Thanks in advance.
>
> Fay Curtis
> 76 Glenbrook that had same problem, but has electrolevel 1 system
> Kneeland, Ca
>
> On Sunday, June 18, 2017, Matt Colie wrote:
>
>> Nathan wrote on Sun, 18 June 2017 10:46
>>> Hello everyone, this is my first post on this forum so please correct me
>> if this is the wrong place to post. Thanks!
>>> I recently bought a 1973 gmc motor home with the 455 olds motor. It had
>> not run since 1994, so I changed all fluids and the battery and started it
>>> up. However, the air suspension would not raise the back of the motor
>> home. So I drove it home at about 10mph. The air suspension is the first
>> thing
>>> I would like to fix, but I am not sure where to start. Any advice would
>> be greatly appreciated. (I tried to use the leveling controls to raise the
>>> back, but that did not chance anything)
>>> Thanks
>>> Nathan
>>
>> Nathan,
>>
>> Welcome to the group, family, cult, asylum....
>>
>> This is the RIGHT place to post questions. If you scroll down, you will
>> find that I still am, and I have owned our coach for 12 years and 60K+
>> miles.
>>
>> Finding your way here was the very best thing that you could do. This is
>> an uncommon community of owners that want to see you enjoy what your coach
>> can do for you as much as we all know it can. Just be aware that this is
>> a 44 year old "truck" (it isn't a truck chassis) with a 44 year old cabin on
>> it that has been though a multi-decade earthquake. It will require
>> maintenance, but if you keep up with that maintenance, she can be
>> reliable. In
>> fact, she can be as reliable as anything just off the dealer lot.
>>
>> Now, about the air suspension. It you digest the two papers that Wally
>> pointed you to, you will learn virtually all you need to know to make it
>> work
>> correctly. Until you have it at least nearly functional, do not buy any
>> parts you do not need. The basic system's weak point (imho) is the
>> compressor. The second, and you have to have a compressor to find it is
>> the body joint in the control valves. This joint is made with a
>> cork/composite gasket that is wrong for the application. (I have a fix
>> that works if the gasket is not damaged.) When you get pressure in the
>> system
>> and have the valves pulled out, check that joint early in the game. When
>> you learn enough to frame a question, bring it back here. You will get a
>> good answer.
>>
>> If you have not downloaded the documentation from Bdub's, this would be a
>> good time. You particularly need manual X7425. Your coach is a 73-23 and
>> there is a lot about it that was changed for later (that are covered in
>> the X7525 manual). Believe me when I tell you this (read my sigfile).
>>
>> Well, here is a part that I like a lot. You have just become a member of
>> an amazing community. These people will be an unbelievable resource. To
>> aid this, please build a useful sigfile. Go to > Settings> and scroll down to the signiture box. Fill in your name, a bit
>> about
>> the coach, and a geographic reference. This is all needed so, we know who
>> we talked to, what is special about the coach and if you are in striking
>> range for someone that wants to help.
>>
>> This supportive and helping community so like that of the watermen of my
>> world that I have taken to welcoming any that arrive here much as a new
>> owner
>> or vessel is welcomed there just because I feel it is fitting. So,
>>
>> May the Good Lord bless this coach and all those that set forth within her.
>>
>> Welcome Nathan
>>
>> Matt
>>
>> --
>> Matt & Mary Colie - '73 Glacier 23 - Members GMCMI, GMCGL, GMCES
>> Still Loving OE Rear Drum Brakes with Applied Control Arms
>> SE Michigan - Twixt A2 and Detroit
>>
>> _______________________________________________
>> 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
Gary Worobec
garytwmw@gmail.com
(o) 951-763-0518
(cell) 773-230-6226
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| Re: [GMCnet] Air suspension and leveling system [message #319229 is a reply to message #319228] |
Sun, 18 June 2017 12:06 |
Burt and Faye curtis
Messages: 256
Registered: June 2012
Karma: 4
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Senior Member |
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Thanks Gary. Will take a look there. Could you maybe post a picture of what
yours looks like?
Fay Curtis
76 Glenbrook
Kneeland, Ca
On Sunday, June 18, 2017, Gary Worobec wrote:
> On my 73 the pressure switch is viewable on the drivers side as you open
> the front drivers side hatch. Probably about a foot in.
>
>
>> On Jun 18, 2017, at 9:32 AM, Burt and Faye curtis curtisunlimitedbandf@gmail.com > wrote:
>>
>> Friend had a 73 in which the compressor does not shut off. I am
> suspecting
>> that the pressure switch either is not hooked up or is not working. Her
>> coach is using the Dana compressor which is not the one shown in the
> early
>> 73 workshop manual and is up in front of driver's wheel area.
>> Would anyone know where to start looking for the pressure switch? Oh,
> there
>> seems to be no air leaks, so don't believe that is why it keeps running.
>> Nice article from Eastern States, but like the workshop manual, it
> doesn't
>> address a compressor that just won't stop.
>>
>> Thanks in advance.
>>
>> Fay Curtis
>> 76 Glenbrook that had same problem, but has electrolevel 1 system
>> Kneeland, Ca
>>
>> On Sunday, June 18, 2017, Matt Colie > wrote:
>>
>>> Nathan wrote on Sun, 18 June 2017 10:46
>>>> Hello everyone, this is my first post on this forum so please correct
> me
>>> if this is the wrong place to post. Thanks!
>>>> I recently bought a 1973 gmc motor home with the 455 olds motor. It had
>>> not run since 1994, so I changed all fluids and the battery and started
> it
>>>> up. However, the air suspension would not raise the back of the motor
>>> home. So I drove it home at about 10mph. The air suspension is the first
>>> thing
>>>> I would like to fix, but I am not sure where to start. Any advice would
>>> be greatly appreciated. (I tried to use the leveling controls to raise
> the
>>>> back, but that did not chance anything)
>>>> Thanks
>>>> Nathan
>>>
>>> Nathan,
>>>
>>> Welcome to the group, family, cult, asylum....
>>>
>>> This is the RIGHT place to post questions. If you scroll down, you will
>>> find that I still am, and I have owned our coach for 12 years and 60K+
>>> miles.
>>>
>>> Finding your way here was the very best thing that you could do. This
> is
>>> an uncommon community of owners that want to see you enjoy what your
> coach
>>> can do for you as much as we all know it can. Just be aware that this
> is
>>> a 44 year old "truck" (it isn't a truck chassis) with a 44 year old
> cabin on
>>> it that has been though a multi-decade earthquake. It will require
>>> maintenance, but if you keep up with that maintenance, she can be
>>> reliable. In
>>> fact, she can be as reliable as anything just off the dealer lot.
>>>
>>> Now, about the air suspension. It you digest the two papers that Wally
>>> pointed you to, you will learn virtually all you need to know to make it
>>> work
>>> correctly. Until you have it at least nearly functional, do not buy any
>>> parts you do not need. The basic system's weak point (imho) is the
>>> compressor. The second, and you have to have a compressor to find it is
>>> the body joint in the control valves. This joint is made with a
>>> cork/composite gasket that is wrong for the application. (I have a fix
>>> that works if the gasket is not damaged.) When you get pressure in the
>>> system
>>> and have the valves pulled out, check that joint early in the game.
> When
>>> you learn enough to frame a question, bring it back here. You will get
> a
>>> good answer.
>>>
>>> If you have not downloaded the documentation from Bdub's, this would be
> a
>>> good time. You particularly need manual X7425. Your coach is a 73-23
> and
>>> there is a lot about it that was changed for later (that are covered in
>>> the X7525 manual). Believe me when I tell you this (read my sigfile).
>>>
>>> Well, here is a part that I like a lot. You have just become a member
> of
>>> an amazing community. These people will be an unbelievable resource.
> To
>>> aid this, please build a useful sigfile. Go to >> Settings> and scroll down to the signiture box. Fill in your name, a
> bit
>>> about
>>> the coach, and a geographic reference. This is all needed so, we know
> who
>>> we talked to, what is special about the coach and if you are in striking
>>> range for someone that wants to help.
>>>
>>> This supportive and helping community so like that of the watermen of my
>>> world that I have taken to welcoming any that arrive here much as a new
>>> owner
>>> or vessel is welcomed there just because I feel it is fitting. So,
>>>
>>> May the Good Lord bless this coach and all those that set forth within
> her.
>>>
>>> Welcome Nathan
>>>
>>> Matt
>>>
>>> --
>>> Matt & Mary Colie - '73 Glacier 23 - Members GMCMI, GMCGL, GMCES
>>> Still Loving OE Rear Drum Brakes with Applied Control Arms
>>> SE Michigan - Twixt A2 and Detroit
>>>
>>> _______________________________________________
>>> 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
>
> Gary Worobec
> garytwmw@gmail.com
> (o) 951-763-0518
> (cell) 773-230-6226
>
>
>
>
> _______________________________________________
> 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:
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| Re: [GMCnet] Air suspension and leveling system [message #319238 is a reply to message #319229] |
Sun, 18 June 2017 14:47 |
Gary Worobec
Messages: 867
Registered: May 2005
Karma: -1
|
Senior Member |
|
|
Faye, I replaced all of my air stuff a couple of years ago so my pressure switch, compressor and tank are all relocated however I’m sure someone out there can snap a photo of an OEM system for you.
> On Jun 18, 2017, at 10:06 AM, Burt and Faye curtis wrote:
>
> Thanks Gary. Will take a look there. Could you maybe post a picture of what
> yours looks like?
>
> Fay Curtis
> 76 Glenbrook
> Kneeland, Ca
>
> On Sunday, June 18, 2017, Gary Worobec wrote:
>
>> On my 73 the pressure switch is viewable on the drivers side as you open
>> the front drivers side hatch. Probably about a foot in.
>>
>>
>>> On Jun 18, 2017, at 9:32 AM, Burt and Faye curtis > curtisunlimitedbandf@gmail.com > wrote:
>>>
>>> Friend had a 73 in which the compressor does not shut off. I am
>> suspecting
>>> that the pressure switch either is not hooked up or is not working. Her
>>> coach is using the Dana compressor which is not the one shown in the
>> early
>>> 73 workshop manual and is up in front of driver's wheel area.
>>> Would anyone know where to start looking for the pressure switch? Oh,
>> there
>>> seems to be no air leaks, so don't believe that is why it keeps running.
>>> Nice article from Eastern States, but like the workshop manual, it
>> doesn't
>>> address a compressor that just won't stop.
>>>
>>> Thanks in advance.
>>>
>>> Fay Curtis
>>> 76 Glenbrook that had same problem, but has electrolevel 1 system
>>> Kneeland, Ca
>>>
>>> On Sunday, June 18, 2017, Matt Colie > > wrote:
>>>
>>>> Nathan wrote on Sun, 18 June 2017 10:46
>>>> > Hello everyone, this is my first post on this forum so please correct
>> me
>>>> if this is the wrong place to post. Thanks!
>>>> > I recently bought a 1973 gmc motor home with the 455 olds motor. It had
>>>> not run since 1994, so I changed all fluids and the battery and started
>> it
>>>> > up. However, the air suspension would not raise the back of the motor
>>>> home. So I drove it home at about 10mph. The air suspension is the first
>>>> thing
>>>> > I would like to fix, but I am not sure where to start. Any advice would
>>>> be greatly appreciated. (I tried to use the leveling controls to raise
>> the
>>>> > back, but that did not chance anything)
>>>> > Thanks
>>>> > Nathan
>>>>
>>>> Nathan,
>>>>
>>>> Welcome to the group, family, cult, asylum....
>>>>
>>>> This is the RIGHT place to post questions. If you scroll down, you will
>>>> find that I still am, and I have owned our coach for 12 years and 60K+
>>>> miles.
>>>>
>>>> Finding your way here was the very best thing that you could do. This
>> is
>>>> an uncommon community of owners that want to see you enjoy what your
>> coach
>>>> can do for you as much as we all know it can. Just be aware that this
>> is
>>>> a 44 year old "truck" (it isn't a truck chassis) with a 44 year old
>> cabin on
>>>> it that has been though a multi-decade earthquake. It will require
>>>> maintenance, but if you keep up with that maintenance, she can be
>>>> reliable. In
>>>> fact, she can be as reliable as anything just off the dealer lot.
>>>>
>>>> Now, about the air suspension. It you digest the two papers that Wally
>>>> pointed you to, you will learn virtually all you need to know to make it
>>>> work
>>>> correctly. Until you have it at least nearly functional, do not buy any
>>>> parts you do not need. The basic system's weak point (imho) is the
>>>> compressor. The second, and you have to have a compressor to find it is
>>>> the body joint in the control valves. This joint is made with a
>>>> cork/composite gasket that is wrong for the application. (I have a fix
>>>> that works if the gasket is not damaged.) When you get pressure in the
>>>> system
>>>> and have the valves pulled out, check that joint early in the game.
>> When
>>>> you learn enough to frame a question, bring it back here. You will get
>> a
>>>> good answer.
>>>>
>>>> If you have not downloaded the documentation from Bdub's, this would be
>> a
>>>> good time. You particularly need manual X7425. Your coach is a 73-23
>> and
>>>> there is a lot about it that was changed for later (that are covered in
>>>> the X7525 manual). Believe me when I tell you this (read my sigfile).
>>>>
>>>> Well, here is a part that I like a lot. You have just become a member
>> of
>>>> an amazing community. These people will be an unbelievable resource.
>> To
>>>> aid this, please build a useful sigfile. Go to >>> Settings> and scroll down to the signiture box. Fill in your name, a
>> bit
>>>> about
>>>> the coach, and a geographic reference. This is all needed so, we know
>> who
>>>> we talked to, what is special about the coach and if you are in striking
>>>> range for someone that wants to help.
>>>>
>>>> This supportive and helping community so like that of the watermen of my
>>>> world that I have taken to welcoming any that arrive here much as a new
>>>> owner
>>>> or vessel is welcomed there just because I feel it is fitting. So,
>>>>
>>>> May the Good Lord bless this coach and all those that set forth within
>> her.
>>>>
>>>> Welcome Nathan
>>>>
>>>> Matt
>>>>
>>>> --
>>>> Matt & Mary Colie - '73 Glacier 23 - Members GMCMI, GMCGL, GMCES
>>>> Still Loving OE Rear Drum Brakes with Applied Control Arms
>>>> SE Michigan - Twixt A2 and Detroit
>>>>
>>>> _______________________________________________
>>>> 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
>>
>> Gary Worobec
>> garytwmw@gmail.com
>> (o) 951-763-0518
>> (cell) 773-230-6226
>>
>>
>>
>>
>> _______________________________________________
>> 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
Gary Worobec
garytwmw@gmail.com
(o) 951-763-0518
(cell) 773-230-6226
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| Re: Air suspension and leveling system [message #319239 is a reply to message #319213] |
Sun, 18 June 2017 15:16 |
A Hamilto
Messages: 4508
Registered: April 2011
Karma: 39
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Senior Member |
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Nathan wrote on Sun, 18 June 2017 09:46Hello everyone, this is my first post on this forum so please correct me if this is the wrong place to post. Thanks!
I recently bought a 1973 gmc motor home with the 455 olds motor. It had not run since 1994, so I changed all fluids and the battery and started it up. However, the air suspension would not raise the back of the motor home. So I drove it home at about 10mph. The air suspension is the first thing I would like to fix, but I am not sure where to start. Any advice would be greatly appreciated. (I tried to use the leveling controls to raise the back, but that did not chance anything)
Thanks
Nathan
First off, check to see if the tires wore through the wheel well liners or otherwise separated the liner from the floor. 73s had wheel wells that weren't quite tall enough.
As far as the airbags raising and/or leveling, there are lots of things to check. Some have mentioned that people put shut-off valves at the bag. Check and see if it has them, and if they are in the OFF position.
Then see if the compressor runs. Do that by turning the key to the "Run" position and listen for the compressor. If it doesn't run, check to see if it has been removed, then check the circuit breaker for the compressor. The circuit breaker is on the fuse block behind the glove compartment.
If the compressor runs, see if it builds up pressure. If not, there might be a massive leak somewhere, or you might need a new compressor.
Report back here after you get that far. Generally, if the compressor runs, and makes a little pressure, and there are no shut off valves in the line, it will either hiss at a leak, or raise the bags at least a little.
Most important, read this:
http://www.gmceast.com/technical/Denney_Power_Level_System.pdf
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| Re: [GMCnet] Air suspension and leveling system [message #319244 is a reply to message #319239] |
Sun, 18 June 2017 16:53 |
Mr ERFisher
Messages: 7117
Registered: August 2005
Karma: 2
|
Senior Member |
|
|
Read here
http://gmcmotorhome.info/wireless.html
On Sun, Jun 18, 2017 at 1:17 PM A. wrote:
> Nathan wrote on Sun, 18 June 2017 09:46
>> Hello everyone, this is my first post on this forum so please correct me
> if this is the wrong place to post. Thanks!
>> I recently bought a 1973 gmc motor home with the 455 olds motor. It had
> not run since 1994, so I changed all fluids and the battery and started it
>> up. However, the air suspension would not raise the back of the motor
> home. So I drove it home at about 10mph. The air suspension is the first
> thing
>> I would like to fix, but I am not sure where to start. Any advice would
> be greatly appreciated. (I tried to use the leveling controls to raise the
>> back, but that did not chance anything)
>> Thanks
>> Nathan
>
> First off, check to see if the tires wore through the wheel well liners or
> otherwise separated the liner from the floor. 73s had wheel wells that
> weren't quite tall enough.
>
> As far as the airbags raising and/or leveling, there are lots of things to
> check. Some have mentioned that people put shut-off valves at the bag.
> Check and see if it has them, and if they are in the OFF position.
>
> Then see if the compressor runs. Do that by turning the key to the "Run"
> position and listen for the compressor. If it doesn't run, check to see if
> it
> has been removed, then check the circuit breaker for the compressor. The
> circuit breaker is on the fuse block behind the glove compartment.
>
> If the compressor runs, see if it builds up pressure. If not, there might
> be a massive leak somewhere, or you might need a new compressor.
>
> Report back here after you get that far. Generally, if the compressor
> runs, and makes a little pressure, and there are no shut off valves in the
> line,
> it will either hiss at a leak, or raise the bags at least a little.
>
> Most important, read this:
>
> http://www.gmceast.com/technical/Denney_Power_Level_System.pdf
>
> _______________________________________________
> 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] Air suspension and leveling system [message #319268 is a reply to message #319262] |
Sun, 18 June 2017 21:06 |
Richard Denney
Messages: 920
Registered: April 2010
Karma: 9
|
Senior Member |
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|
Matt, that's exactly the reason for automatic ride height on GMC's.
It's also the reason I moved my water tank to a centered position under the
bed when I replaced the Adobe Posterior. Trying to correct for a diagonal
balance mismatch is harder than just tracking changes in rear load.
The factory Power Level system is simple and straightforward, easy to
troubleshoot, and generally bulletproof once the leaks are managed. It has
little of the complexity of the later systems. I could see replacing an
Electro Level II system that has bad pumps and electric air valves with a
wireless system, but it just isn't that hard to make a Power Level system
work well.
Rick "thinking if GM had original used valves of the quality JR Slaten
uses, they'd have never needed to 'upgrade' the air system" Denney
On Sun, Jun 18, 2017 at 7:39 PM Matt Colie wrote:
> Nathan,
>
> Your coach is a 73-23, so it will probably cross a scale at less than
> 9700#. This makes the weight of the fuel and water more of a factor than
> it is
> in the later longer and heavier coaches. (Many Royales top 12000.)
>
> I know this because I one had the coach ride height set with the water and
> fuel low.
> First I put on 30 gallons of water (~250#) and shortly later took on 48
> gallons of gasoline (~290#) and the coach's handling got squirrely. Some
> will
> tell you it makes no difference. 500# in the ass end does make a
> difference, and the coach can handle it if it is given a chance.
>
> Then I set the knobs to travel and things got better.
>
> Matt
> --
> Matt & Mary Colie - '73 Glacier 23 - Members GMCMI, GMCGL, GMCES
> Still Loving OE Rear Drum Brakes with Applied Control Arms
> SE Michigan - Twixt A2 and Detroit
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
--
Rick Denney
73 x-Glacier 230 "Jaws"
Off-list email to rick at rickdenney dot com
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| Re: [GMCnet] Air suspension and leveling system [message #319270 is a reply to message #319268] |
Sun, 18 June 2017 23:15 |
 |
USAussie
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
|
Senior Member |
|
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Rich, Matt,
I agree with both of you!
If the GMC suspension engineers didn't think the automatic leveling system
was necessary why did they install it?
AND why did the accountants approve it?
Regards,
Rob M.
The Pedantic Mechanic
USAussie - Downunder
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 Richard
Denney
Sent: Monday, June 19, 2017 12:07 PM
To: gmclist@list.gmcnet.org
Subject: Re: [GMCnet] Air suspension and leveling system
Matt, that's exactly the reason for automatic ride height on GMC's.
It's also the reason I moved my water tank to a centered position under the
bed when I replaced the Adobe Posterior. Trying to correct for a diagonal
balance mismatch is harder than just tracking changes in rear load.
The factory Power Level system is simple and straightforward, easy to
troubleshoot, and generally bulletproof once the leaks are managed. It has
little of the complexity of the later systems. I could see replacing an
Electro Level II system that has bad pumps and electric air valves with a
wireless system, but it just isn't that hard to make a Power Level system
work well.
Rick "thinking if GM had original used valves of the quality JR Slaten
uses, they'd have never needed to 'upgrade' the air system" Denney
On Sun, Jun 18, 2017 at 7:39 PM Matt Colie wrote:
> Nathan,
>
> Your coach is a 73-23, so it will probably cross a scale at less than
> 9700#. This makes the weight of the fuel and water more of a factor than
> it is
> in the later longer and heavier coaches. (Many Royales top 12000.)
>
> I know this because I one had the coach ride height set with the water and
> fuel low.
> First I put on 30 gallons of water (~250#) and shortly later took on 48
> gallons of gasoline (~290#) and the coach's handling got squirrely. Some
> will
> tell you it makes no difference. 500# in the ass end does make a
> difference, and the coach can handle it if it is given a chance.
>
> Then I set the knobs to travel and things got better.
>
> Matt
> --
> Matt & Mary Colie - '73 Glacier 23 - Members GMCMI, GMCGL, GMCES
> Still Loving OE Rear Drum Brakes with Applied Control Arms
> SE Michigan - Twixt A2 and Detroit
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
--
Rick Denney
73 x-Glacier 230 "Jaws"
Off-list email to rick at rickdenney dot com
_______________________________________________
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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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| Re: Air suspension and leveling system [message #319296 is a reply to message #319213] |
Mon, 19 June 2017 12:36 |
lqqkatjon
Messages: 2324
Registered: October 2010
Location: St. Cloud, MN
Karma: 5
|
Senior Member |
|
|
Welcome. I will add my two cents.
1st, like Ken said, check for the shut off valves. If they do not have them, install them, it will make troubleshooting easier and give you time to diagnose all the air system problems you have now and may have in the future. With the shut/off isolators you can pump up the bags with a working or semi working system and not have to drive at 10mph with bumper dragging.
You can chase the valves/ fittings. Or buy from vender(much easier).
Scroll down past his air bags:
http://www.gmcmotorhomemarketplace.com/sully/
And or
http://www.appliedgmc.com/prod.itml/icOid/690
Then and for faye as well, you need to know if the compressor runs and can produce pressure. It takes 90+ pounds in oem airbags and i have seen two cases this spring the original compressor was weak and could not pump well enough to shut off the pressure switch. (At like 120-130 psi). I have a cheap air guage T ed onto my air tank. Then if it is getting enough pressure, and pump is still on, the pressure switch is common, and you can then start hunting down leaks.
On a coach that has been sitting, I personally would install the airbag valves/isolators/schrader valves. Pump up airbags to a level height that is 1.5 inches lower in back then front. And drive the coach. Fix the obviius, but there might be more items that need attention then spending alot of time figuring out if you have air leaks, leveling valves bad, and dash valves bad. Or having to spend a couple hundred on a new compressor. Get your list together and figure out what is most important to address next. Make it stop, make it go. And then make it comfortable.
Get out and enjoy the coach.
Jon Roche
75 palm beach
EBL EFI, manny headers, Micro Level, rebuilt most of coach now.
St. Cloud, MN
http://lqqkatjon.blogspot.com/
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| Re: [GMCnet] Air suspension and leveling system [message #319298 is a reply to message #319296] |
Mon, 19 June 2017 14:27 |
sgltrac
Messages: 2797
Registered: April 2011
Karma: 1
|
Senior Member |
|
|
If the coach is the early model (73-75) and was driven any real distance
with the bags deflated it is likely a tire has rubbed through one or both
of the bags. Hopefully this is not the case or if it is the bag (s) were
already bad. I suggest verifying clearance between the deflated bags before
any further operation of the coach and then follow the earlier advice
offered here.
Sully
77 eleganza 2
Seattle
On Mon, Jun 19, 2017 at 10:43 AM Jon Roche wrote:
> Welcome. I will add my two cents.
>
> 1st, like Ken said, check for the shut off valves. If they do not have
> them, install them, it will make troubleshooting easier and give you time
> to diagnose all the air system problems you have now and may have in the
> future. With the shut/off isolators you can pump up the bags with a
> working
> or semi working system and not have to drive at 10mph with bumper dragging.
>
> You can chase the valves/ fittings. Or buy from vender(much easier).
>
> Scroll down past his air bags:
> http://www.gmcmotorhomemarketplace.com/sully/
>
> And or
> http://www.appliedgmc.com/prod.itml/icOid/690
>
>
> Then and for faye as well, you need to know if the compressor runs and
> can produce pressure. It takes 90+ pounds in oem airbags and i have seen
> two
> cases this spring the original compressor was weak and could not pump well
> enough to shut off the pressure switch. (At like 120-130 psi). I have a
> cheap air guage T ed onto my air tank. Then if it is getting enough
> pressure, and pump is still on, the pressure switch is common, and you can
> then start hunting down leaks.
>
> On a coach that has been sitting, I personally would install the airbag
> valves/isolators/schrader valves. Pump up airbags to a level height that
> is
> 1.5 inches lower in back then front. And drive the coach. Fix the
> obviius, but there might be more items that need attention then spending
> alot of
> time figuring out if you have air leaks, leveling valves bad, and dash
> valves bad. Or having to spend a couple hundred on a new compressor.
> Get
> your list together and figure out what is most important to address next.
> Make it stop, make it go. And then make it comfortable.
>
> Get out and enjoy the coach.
>
> --
> Jon Roche
> 75 palm beach
> St. Cloud, MN
> http://lqqkatjon.blogspot.com/
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
_______________________________________________
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Sully
77 Royale basket case.
Future motorhome land speed record holder(bucket list)
Seattle, Wa.
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| Re: [GMCnet] Air suspension and leveling system [message #319324 is a reply to message #319244] |
Tue, 20 June 2017 08:57 |
Richard Denney
Messages: 920
Registered: April 2010
Karma: 9
|
Senior Member |
|
|
Okay, all this came into existence during my period of GMCnet dormancy.
But I'm looking at the system, and it seems to me that you have to know
what pressure achieves the proper ride height for any condition of load. My
coach has 1300-1500 pounds on each rear tire with full water and 30 gallons
of fuel, or abut 5600 pounds total on the rear wheels. Fuel and water add
or subtract over 500 pounds, or 10% of the weight on the rear. I'm not sure
I can reliably use bag pressure to attain the correct ride height, even
after calibrating it.
Once I sorted out my leaks (none of which were in the air tubing going from
front to back), my system works fine and has for many years. Also, my pump
is already at the front, and I'm not sure I have space for the air system
in the back.
If I had an Electro-Level II system with bad solenoid valves, dead pumps,
and cracked plastic fittings, the wireless system would be more appealing.
But a '73 has brass fittings, and the most one usually has to replace is
the pump and the control valves (and maybe a few bits like the pressure
switch and the tank drain plug).
Rick "not sure what failure modes the wireless system corrects compared to
a Power Level with JR valves" Denney
On Sun, Jun 18, 2017 at 5:53 PM, gene Fisher wrote:
> Read here
> http://gmcmotorhome.info/wireless.html
>
>
>
>
> On Sun, Jun 18, 2017 at 1:17 PM A. wrote:
>
>> Nathan wrote on Sun, 18 June 2017 09:46
>>> Hello everyone, this is my first post on this forum so please correct
> me
>> if this is the wrong place to post. Thanks!
>>> I recently bought a 1973 gmc motor home with the 455 olds motor. It had
>> not run since 1994, so I changed all fluids and the battery and started
> it
>>> up. However, the air suspension would not raise the back of the motor
>> home. So I drove it home at about 10mph. The air suspension is the first
>> thing
>>> I would like to fix, but I am not sure where to start. Any advice would
>> be greatly appreciated. (I tried to use the leveling controls to raise
> the
>>> back, but that did not chance anything)
>>> Thanks
>>> Nathan
>>
>> First off, check to see if the tires wore through the wheel well liners
> or
>> otherwise separated the liner from the floor. 73s had wheel wells that
>> weren't quite tall enough.
>>
>> As far as the airbags raising and/or leveling, there are lots of things
> to
>> check. Some have mentioned that people put shut-off valves at the bag.
>> Check and see if it has them, and if they are in the OFF position.
>>
>> Then see if the compressor runs. Do that by turning the key to the "Run"
>> position and listen for the compressor. If it doesn't run, check to see
> if
>> it
>> has been removed, then check the circuit breaker for the compressor. The
>> circuit breaker is on the fuse block behind the glove compartment.
>>
>> If the compressor runs, see if it builds up pressure. If not, there might
>> be a massive leak somewhere, or you might need a new compressor.
>>
>> Report back here after you get that far. Generally, if the compressor
>> runs, and makes a little pressure, and there are no shut off valves in
> the
>> line,
>> it will either hiss at a leak, or raise the bags at least a little.
>>
>> Most important, read this:
>>
>> http://www.gmceast.com/technical/Denney_Power_Level_System.pdf
>>
>> _______________________________________________
>> 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
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
--
'73 X-Glacier 230 "Jaws"
Northern Virginia
Offlist email: rick at rickdenney dot com
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