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[GMCnet] Replacing air bag system [message #248111]

Mon, 21 April 2014 20:25

glwgmc

Messages: 1014
Registered: June 2004

Karma: 10

Senior Member

Hi Kerry,

This one has been discussed a number of times before. Turns out there is enough hysteresis in the rear suspension that air pressure does represent a very close analog for ride height. It won't be perfect in all cases, but it will be spot on for the majority of cases. When we purchased the Royale more than a decade ago one air pump was bad so I ran with Schrader valves in the ends of the bags "until I got around to fixing it" Years later I never had and never found the need. I could determine quite quickly what pressure resulted in my coach being at correct ride height going down the road. From a full fuel load to an empty one, from a full water load to an empty tank, from full to empty holding tanks the ride height at a given pressure in the bags changed very little, less than the slop in the factory ride height mechanism (factory spec is +- 3/8" if the ride height mechanism is working perfectly). Interesting that the factory ride height spec is +- 1/4" so it was alway
s curious to me how one was supposed to stay within that ride height when it was being controlled by a gizmo with an even greater tolerance. But, that is how it is/was. As an experiment, measure your ride height and then have four people stand on the back bumper and measure it again and see how little difference there is.

Anyway, when I first heard about the wireless air system I jumped on it just to keep my head and body away from the bag as I blew it up or let it down to level. I always felt a bit uneasy being so close to a decades old air bag with close to 100 pounds of air in it. Since I installed the wireless air controller (I put on bag extenders to lower the op pressure to 75psi for my coach going down the road) I find it very convenient and ride height very stable and predictable. I have a stock system on the Clasco and can't find a nickles worth of difference between them in real world use.

Hope this helps.

Jerry
Jerry Work
The Dovetail Joint
Fine furniture designed and hand crafted in the 1907 former Masonic Temple building in historic Kerby, OR
Visitors always welcome!
glwork@mac.com
http://jerrywork.com
++++++++++++++++
Message: 1
Date: Mon, 21 Apr 2014 14:17:47 -0500
From: Kerry Pinkerton <Pinkertonk@MCHSI.com>
Subject: Re: [GMCnet] C
To: gmclist@temp.gmcnet.org
Message-ID: <3c90d.53556edb@gmc.mybirdfeeder.net>
Content-Type: text/plain; charset="ISO-8859-15"

Perhaps I'm missing something but how does the wireless system know what the correct height is? Bag pressure is not the same thing as ride height.
--
Kerry Pinkerton

North Alabama, near Huntsville,

77 Eleganza II, "The Lady", 403CI, also a 76 Eleganza being re-bodied as an Art Deco car hauler
+++++++++++++++

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Jerry & Sharon Work
78 Royale
Kerby, OR

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Re: [GMCnet] Replacing air bag system [message #248116 is a reply to message #248111]

Mon, 21 April 2014 20:50

Mr ERFisher

Messages: 7117
Registered: August 2005

Karma: 2

Senior Member

Tanks. Helps me
Erf

FREE WIFI @ Mickey D

On Apr 21, 2014, at 6:25 PM, Work Jerry <glwork@mac.com> wrote:

> Hi Kerry,
>
> This one has been discussed a number of times before. Turns out there is enough hysteresis in the rear suspension that air pressure does represent a very close analog for ride height. It won't be perfect in all cases, but it will be spot on for the majority of cases. When we purchased the Royale more than a decade ago one air pump was bad so I ran with Schrader valves in the ends of the bags "until I got around to fixing it" Years later I never had and never found the need. I could determine quite quickly what pressure resulted in my coach being at correct ride height going down the road. From a full fuel load to an empty one, from a full water load to an empty tank, from full to empty holding tanks the ride height at a given pressure in the bags changed very little, less than the slop in the factory ride height mechanism (factory spec is +- 3/8" if the ride height mechanism is working perfectly). Interesting that the factory ride height spec is +- 1/4" so it was alw
ay
> s curious to me how one was supposed to stay within that ride height when it was being controlled by a gizmo with an even greater tolerance. But, that is how it is/was. As an experiment, measure your ride height and then have four people stand on the back bumper and measure it again and see how little difference there is.
>
> Anyway, when I first heard about the wireless air system I jumped on it just to keep my head and body away from the bag as I blew it up or let it down to level. I always felt a bit uneasy being so close to a decades old air bag with close to 100 pounds of air in it. Since I installed the wireless air controller (I put on bag extenders to lower the op pressure to 75psi for my coach going down the road) I find it very convenient and ride height very stable and predictable. I have a stock system on the Clasco and can't find a nickles worth of difference between them in real world use.
>
> Hope this helps.
>
> Jerry
> Jerry Work
> The Dovetail Joint
> Fine furniture designed and hand crafted in the 1907 former Masonic Temple building in historic Kerby, OR
> Visitors always welcome!
> glwork@mac.com
> http://jerrywork.com
> ++++++++++++++++
> Message: 1
> Date: Mon, 21 Apr 2014 14:17:47 -0500
> From: Kerry Pinkerton <Pinkertonk@MCHSI.com>
> Subject: Re: [GMCnet] C
> To: gmclist@temp.gmcnet.org
> Message-ID: <3c90d.53556edb@gmc.mybirdfeeder.net>
> Content-Type: text/plain; charset="ISO-8859-15"
>
>
>
> Perhaps I'm missing something but how does the wireless system know what the correct height is? Bag pressure is not the same thing as ride height.
> --
> Kerry Pinkerton
>
> North Alabama, near Huntsville,
>
> 77 Eleganza II, "The Lady", 403CI, also a 76 Eleganza being re-bodied as an Art Deco car hauler
> +++++++++++++++
>
>
>
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
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Re: [GMCnet] Replacing air bag system [message #248119 is a reply to message #248111]

Mon, 21 April 2014 21:26

sgltrac

Messages: 2797
Registered: April 2011

Karma: 1

Senior Member

Air pressure or lack thereof dictates the height. End of story. The amount of air pressure required to attain a given height will be dictated by type of suspension and loaded weight. The variance in typical loaded weight will not vary much in comparison to total weight supported by the arlirbags. Therefore once a coach is set with wireless carrying a typical load it is safe to say that the preset pressure will be adequate for a period of time assuming full water tank and 50% fuel since it seems that full tanks transform into half full before the gas station is out of sight and fresh water doesn't leave until waste tanks are empty. To keep an eye on things it would be a good idea to check the "calibration" once in awhile by commanding the preset and quick measure of the result to see if the selected pressure is still adequate. If I have a properly functioning oem system ( as I do) obviously that is better. I you are faced with replacement of many expensive parts and much mecha
nical labor to get the current "automatic" system functional I see no other option then the wireless if you don't want to be eyeballing your coach rear suspension in parking lots and gas stations playing hose monkey scurrying around before the air machine shuts off

Bring lots o quarters.

Todd Sullivan

Sully
77 royale
Seattle

> On Apr 21, 2014, at 6:25 PM, Work Jerry <glwork@mac.com> wrote:
>
> Hi Kerry,
>
> This one has been discussed a number of times before. Turns out there is enough hysteresis in the rear suspension that air pressure does represent a very close analog for ride height. It won't be perfect in all cases, but it will be spot on for the majority of cases. When we purchased the Royale more than a decade ago one air pump was bad so I ran with Schrader valves in the ends of the bags "until I got around to fixing it" Years later I never had and never found the need. I could determine quite quickly what pressure resulted in my coach being at correct ride height going down the road. From a full fuel load to an empty one, from a full water load to an empty tank, from full to empty holding tanks the ride height at a given pressure in the bags changed very little, less than the slop in the factory ride height mechanism (factory spec is +- 3/8" if the ride height mechanism is working perfectly). Interesting that the factory ride height spec is +- 1/4" so it was alw
ay
> s curious to me how one was supposed to stay within that ride height when it was being controlled by a gizmo with an even greater tolerance. But, that is how it is/was. As an experiment, measure your ride height and then have four people stand on the back bumper and measure it again and see how little difference there is.
>
> Anyway, when I first heard about the wireless air system I jumped on it just to keep my head and body away from the bag as I blew it up or let it down to level. I always felt a bit uneasy being so close to a decades old air bag with close to 100 pounds of air in it. Since I installed the wireless air controller (I put on bag extenders to lower the op pressure to 75psi for my coach going down the road) I find it very convenient and ride height very stable and predictable. I have a stock system on the Clasco and can't find a nickles worth of difference between them in real world use.
>
> Hope this helps.
>
> Jerry
> Jerry Work
> The Dovetail Joint
> Fine furniture designed and hand crafted in the 1907 former Masonic Temple building in historic Kerby, OR
> Visitors always welcome!
> glwork@mac.com
> http://jerrywork.com
> ++++++++++++++++
> Message: 1
> Date: Mon, 21 Apr 2014 14:17:47 -0500
> From: Kerry Pinkerton <Pinkertonk@MCHSI.com>
> Subject: Re: [GMCnet] C
> To: gmclist@temp.gmcnet.org
> Message-ID: <3c90d.53556edb@gmc.mybirdfeeder.net>
> Content-Type: text/plain; charset="ISO-8859-15"
>
>
>
> Perhaps I'm missing something but how does the wireless system know what the correct height is? Bag pressure is not the same thing as ride height.
> --
> Kerry Pinkerton
>
> North Alabama, near Huntsville,
>
> 77 Eleganza II, "The Lady", 403CI, also a 76 Eleganza being re-bodied as an Art Deco car hauler
> +++++++++++++++
>
>
>
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
_______________________________________________
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Unsubscribe or Change List Options:
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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] Replacing air bag system [message #248128 is a reply to message #248119]

Mon, 21 April 2014 22:52

Bob de Kruyff

Messages: 4260
Registered: January 2004
Location: Chandler, AZ

Karma: 1

Senior Member

sgltrac wrote on Mon, 21 April 2014 20:26

Do you guys have a thermostat in your house or a toggle switch or timer?

Bob de Kruyff
78 Eleganza
Chandler, AZ

[Updated on: Mon, 21 April 2014 22:52]

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Re: [GMCnet] Replacing air bag system [message #248135 is a reply to message #248119]

Mon, 21 April 2014 23:54

powerjon

Messages: 2446
Registered: January 2004

Karma: 5

Senior Member

Back in June of 2012 we went thru this same discussion and my comment I made then are still the same for today. The same player then, the same players now. More comments at the end.

“June 19, 2012

Gene, Jim, Mandie and others,

This is not meant to be pissing contest on the merits of various air
systems, lets just get some of the Myths cleared up.

First of all let us agree that the best air ride system for your GMC
is the factory OEM automatic leveling air ride system, wether it be
Power-Level, EL 1 or EL 2. If you have one that is working, by all
means keep it in good shape or have it repaired or renewed if you
can. If you have never had a coach with a working OEM system then you
then the comparison will be difficult.

OK, what else is available for our coaches:

1. Schraders valve and manually putting air in your air bags. Will
get you coach down the road, but is a real PITA!

2. Bovee’s Wireless air System <http://www.appliedgmc.com/prod.itml/icOid/1382>

It is a well engineered substitute for adding air to your air bags and
Gary did a great job on designing and assembling this system. It is a
PRESSURE based system, uses NO leveling valves and is basically the
same concept as using Schraders valves. (Gary's words paraphrased not
mine) That said it does have added benefits over just having
Schraders valves on your air bags.

The following is quoted form Gary's Tech article on the GMC Western
States site. <http://gmcws.org/Tech/Wireless_air.pdf>

(Quote)
a. No more having to go to the bags to fill or release air;
b. No more having to drag out a compressor to air up your bags for
travel.
c. You program the remote digital controller for the proper ride
height and it will
automatically keep the bags air pressure within plus or minus 3
pounds of the
Programmed setting for each bag.
d. The nice thing is when you park at an RV park or are dry camping
you use the remote to
level your coach.
e. When you are ready to hit the road you just push the programmed
button for road travel. It
adds or releases air, whatever is needed for each bag and you are soon
on your way. (This
system has a maximum air pressure limit of 100 pound.)"
(UnQuote)

Allows you to manual adjust the air pressure in your air bags. (a,b &
d) Allows you to automatically return to a predetermined pressure
set point and hold that pressure +/- 3 PSIG. (c & e)

What it does not do is that it DOES NOT automatically compensate for
changes in ride height wether setting stationary or rolling down the
road and your ride height is constantly changing and that can affect
how your coach steers down the road. You STILL have to check the
ride height of your coach to determine the necessary predetermined
pressure requirements for various load conditions the system must
compensate for. Be sure to let it settle between changes to see if
the ride height stabilizes and your good to go at that PSIG. Jerry
Work says this is extremely important when setting right heights both
front and rear in his alignment presentation he gave at the GMCWS
Spring 2012 rally. (available at jerrywork.com see links at bottom
of page) 90% of the coaches that attended the rally drove in with the
ride heights incorrectly set!

System Replacement Cost

To repair the OEM system is very hard to determine and it could be
from several hundred dollars to considerably more. Depends if you
what to keep the OEM system.

The cost for Gary's system is going to be in the $780 range depending
on what you buy or substitute. It is cost effective!

Which is best, it is going to come down to personal choice.

As for Single air Bag per side replacement there are several choices
available.

SullyBilt - You're looking at about $600 depending on the finish you
choose on the mounting brackets and that includes air bags cost which
you purchase yourself. People have found the bags between $110 &
$140. Just need to shop well. <http://www.bdub.net/sully/>

Jim K sells a replacement bag system call MONO bags for $690 for the
pair and only for the standard size tire. Well priced system and bolt
on also. <http://www.appliedgmc.com/prod.itml/icOid/1037>

Zeb Frady @ Southland RV also sells a single bag upgrade.
770-271-750two

If you got the money then both Jim K and Jim B Sell the Quad bag
system. <http://www.appliedgmc.com/prod.itml/icOid/684>

Mandie, to replace your air system with Gary's plus replacing the air
bags your total cost is going to be in the $1400 range +/- plus you
will need to consider labor cost if you cannot do the work yourself.
The choice will be yours.

Ok, I will get off my soap box now. “

COMMENTS FOR TONIGHT:
I agree with Todd’s email comments below. I have always had a coaches that have had operating air ride systems. Our 77 Eleganza II (our first coach) ( EL 1 )was a dream to drive, it was a true 2 finger on the steering wheel going down the road coach. The stretch coach built in 1997 also is a EL 1 system and I spent the time finally this fall to do the ride hight correctly and it drove very well out to Tucson and back this year almost 5800 miles total. It does have a few small air leaks that cause it to leak down air pressure over several days, but I will be going thru that this summer and will photo document that. I also have a complete EL 1 system that I bought GMCREC in Houston a few years back that will be going into the 1975 Avion to replace the Power Level system. I will be doing that because I can.

As for level control weight DOES MAKE A DIFFERENCE. When I finally set the ride height this past fall ( it was off quite a bite both front and rear ) the coach weighed empty about 12,100#, now remember I have a stretch which weights more than the standard 26’. My going down the road with everything in the coach, including the kitchen sink, remember that we are going out for 3+ months, plus full fuel tanks ( 75 gallons ), 1/4 full water and basically empty holding tanks, I have 2 tanks, comes in at about 14,800# without passengers. The ride height between empty and loaded after settling was under a 1/4 inch. My system works pretty good, and I did check the coach tonight in the shop and there was no real difference between the fall 2013 and tonights measurements, empty weight measurement. I have air system pressure gauges that show supply and both left and right air pressure in the air bags. The pressure goes up almost 10# each side for the difference between empty and fully loaded weights.

I have had air bag extenders on my 77 Eleganza II coach, but I noticed that the coach road too soft for me and swayed more, I took them off in 1999 and sold them. I have another set for sale ( New ) if anyone want them. They were very popular in the late 80’s and most of the 90’s. They did reduce the air pressure required. Now Todds new style Sullybag air bag system does also reduce the air pressure in the bags, but that is because of the size ( volume )of the bag that is used and it requires less air pressure for the same spring rate as the OEM bag actually giving it a more stable ride. Our stretch coach has a Buskirk designed 4 bags system ( All Buskirk Stretch coaches have the same system ). It is an upgraded version of Leigh Harrison's 4 bag system, but built out of considerable heavier materials and slightly larger air bags and doesn’t have the issues that the stock Harrison system has. It has a very stable ride going down the road.

Again all comments are welcome and we can discuss them all.

JR Wright
GMC Great Laker MHC
GMC Eastern States
GMCMHI
78 GMC Buskirk 30’ Stretch
1975 GMC Avion (Under Reconstruction)
Michigan

On Apr 21, 2014, at 10:26 PM, Todd Sullivan <sgltrac@gmail.com> wrote:

> Air pressure or lack thereof dictates the height. End of story. The amount of air pressure required to attain a given height will be dictated by type of suspension and loaded weight. The variance in typical loaded weight will not vary much in comparison to total weight supported by the airbags. Therefore once a coach is set with wireless carrying a typical load it is safe to say that the preset pressure will be adequate for a period of time assuming full water tank and 50% fuel since it seems that full tanks transform into half full before the gas station is out of sight and fresh water doesn't leave until waste tanks are empty. To keep an eye on things it would be a good idea to check the "calibration" once in awhile by commanding the preset and quick measure of the result to see if the selected pressure is still adequate. If I have a properly functioning oem system ( as I do) obviously that is better. I you are faced with replacement of many expensive parts and much mecha
> nical labor to get the current "automatic" system functional I see no other option then the wireless if you don't want to be eyeballing your coach rear suspension in parking lots and gas stations playing hose monkey scurrying around before the air machine shuts off
>
> Bring lots o quarters.
>
> Todd Sullivan
>
> Sully
> 77 royale
> Seattle
>
>> On Apr 21, 2014, at 6:25 PM, Work Jerry <glwork@mac.com> wrote:
>>
>> Hi Kerry,
>>
>> This one has been discussed a number of times before. Turns out there is enough hysteresis in the rear suspension that air pressure does represent a very close analog for ride height. It won't be perfect in all cases, but it will be spot on for the majority of cases. When we purchased the Royale more than a decade ago one air pump was bad so I ran with Schrader valves in the ends of the bags "until I got around to fixing it" Years later I never had and never found the need. I could determine quite quickly what pressure resulted in my coach being at correct ride height going down the road. From a full fuel load to an empty one, from a full water load to an empty tank, from full to empty holding tanks the ride height at a given pressure in the bags changed very little, less than the slop in the factory ride height mechanism (factory spec is +- 3/8" if the ride height mechanism is working perfectly). Interesting that the factory ride height spec is +- 1/4" so it was alw
> ay
>> s curious to me how one was supposed to stay within that ride height when it was being controlled by a gizmo with an even greater tolerance. But, that is how it is/was. As an experiment, measure your ride height and then have four people stand on the back bumper and measure it again and see how little difference there is.
>>
>> Anyway, when I first heard about the wireless air system I jumped on it just to keep my head and body away from the bag as I blew it up or let it down to level. I always felt a bit uneasy being so close to a decades old air bag with close to 100 pounds of air in it. Since I installed the wireless air controller (I put on bag extenders to lower the op pressure to 75psi for my coach going down the road) I find it very convenient and ride height very stable and predictable. I have a stock system on the Clasco and can't find a nickles worth of difference between them in real world use.
>>
>> Hope this helps.
>>
>> Jerry
>> Jerry Work
>> The Dovetail Joint
>> Fine furniture designed and hand crafted in the 1907 former Masonic Temple building in historic Kerby, OR
>> Visitors always welcome!
>> glwork@mac.com
>> http://jerrywork.com
>> ++++++++++++++++
>> Message: 1
>> Date: Mon, 21 Apr 2014 14:17:47 -0500
>> From: Kerry Pinkerton <Pinkertonk@MCHSI.com>
>> Subject: Re: [GMCnet] C
>> To: gmclist@temp.gmcnet.org
>> Message-ID: <3c90d.53556edb@gmc.mybirdfeeder.net>
>> Content-Type: text/plain; charset="ISO-8859-15"
>>
>>
>>
>> Perhaps I'm missing something but how does the wireless system know what the correct height is? Bag pressure is not the same thing as ride height.
>> --
>> Kerry Pinkerton
>>
>> North Alabama, near Huntsville,
>>
>> 77 Eleganza II, "The Lady", 403CI, also a 76 Eleganza being re-bodied as an Art Deco car hauler
>> +++++++++++++++
>>
>>
>>
>>
>>
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
>> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist

_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist

J.R. Wright
GMC GreatLaker
GMC Eastern States
GMCMI
78 30' Buskirk Stretch
75 Avion Under Reconstruction
Michigan

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Re: [GMCnet] Replacing air bag system [message #248141 is a reply to message #248135]

Tue, 22 April 2014 01:30

sgltrac

Messages: 2797
Registered: April 2011

Karma: 1

Senior Member

The Sullybilt kit is $400 in hot dip galvanized finish or $375 plain steel for those who want to powder coat or paint. (Powder coated kits look pretty bad ass I think). Bags not supplied with kit due to duplicate shipping of bags from me to you adds more cost than if you purchase direct. Current fi 9294 cost is $125 -$139 each. Shut off w Schrader valves add $70 with no additional shipping if ordered same time as kit ( fits in flat rate usps box kit is in)

Check out your bags then check out www.bdub.net/sully/ then call if you have questions.
2 oh 6 948 five 210

Todd Sullivan

Sully
77 royale
Seattle

> On Apr 21, 2014, at 9:54 PM, John Wright <powerjon@chartermi.net> wrote:
>
> Back in June of 2012 we went thru this same discussion and my comment I made then are still the same for today. The same player then, the same players now. More comments at the end.
>
> “June 19, 2012
>
> Gene, Jim, Mandie and others,
>
> This is not meant to be pissing contest on the merits of various air
> systems, lets just get some of the Myths cleared up.
>
> First of all let us agree that the best air ride system for your GMC
> is the factory OEM automatic leveling air ride system, wether it be
> Power-Level, EL 1 or EL 2. If you have one that is working, by all
> means keep it in good shape or have it repaired or renewed if you
> can. If you have never had a coach with a working OEM system then you
> then the comparison will be difficult.
>
> OK, what else is available for our coaches:
>
> 1. Schraders valve and manually putting air in your air bags. Will
> get you coach down the road, but is a real PITA!
>
> 2. Bovee’s Wireless air System <http://www.appliedgmc.com/prod.itml/icOid/1382>
>
> It is a well engineered substitute for adding air to your air bags and
> Gary did a great job on designing and assembling this system. It is a
> PRESSURE based system, uses NO leveling valves and is basically the
> same concept as using Schraders valves. (Gary's words paraphrased not
> mine) That said it does have added benefits over just having
> Schraders valves on your air bags.
>
> The following is quoted form Gary's Tech article on the GMC Western
> States site. <http://gmcws.org/Tech/Wireless_air.pdf>
>
> (Quote)
> a. No more having to go to the bags to fill or release air;
> b. No more having to drag out a compressor to air up your bags for
> travel.
> c. You program the remote digital controller for the proper ride
> height and it will
> automatically keep the bags air pressure within plus or minus 3
> pounds of the
> Programmed setting for each bag.
> d. The nice thing is when you park at an RV park or are dry camping
> you use the remote to
> level your coach.
> e. When you are ready to hit the road you just push the programmed
> button for road travel. It
> adds or releases air, whatever is needed for each bag and you are soon
> on your way. (This
> system has a maximum air pressure limit of 100 pound.)"
> (UnQuote)
>
> Allows you to manual adjust the air pressure in your air bags. (a,b &
> d) Allows you to automatically return to a predetermined pressure
> set point and hold that pressure +/- 3 PSIG. (c & e)
>
> What it does not do is that it DOES NOT automatically compensate for
> changes in ride height wether setting stationary or rolling down the
> road and your ride height is constantly changing and that can affect
> how your coach steers down the road. You STILL have to check the
> ride height of your coach to determine the necessary predetermined
> pressure requirements for various load conditions the system must
> compensate for. Be sure to let it settle between changes to see if
> the ride height stabilizes and your good to go at that PSIG. Jerry
> Work says this is extremely important when setting right heights both
> front and rear in his alignment presentation he gave at the GMCWS
> Spring 2012 rally. (available at jerrywork.com see links at bottom
> of page) 90% of the coaches that attended the rally drove in with the
> ride heights incorrectly set!
>
> System Replacement Cost
>
> To repair the OEM system is very hard to determine and it could be
> from several hundred dollars to considerably more. Depends if you
> what to keep the OEM system.
>
> The cost for Gary's system is going to be in the $780 range depending
> on what you buy or substitute. It is cost effective!
>
> Which is best, it is going to come down to personal choice.
>
> As for Single air Bag per side replacement there are several choices
> available.
>
> SullyBilt - You're looking at about $600 depending on the finish you
> choose on the mounting brackets and that includes air bags cost which
> you purchase yourself. People have found the bags between $110 &
> $140. Just need to shop well. <http://www.bdub.net/sully/>
>
> Jim K sells a replacement bag system call MONO bags for $690 for the
> pair and only for the standard size tire. Well priced system and bolt
> on also. <http://www.appliedgmc.com/prod.itml/icOid/1037>
>
> Zeb Frady @ Southland RV also sells a single bag upgrade.
> 770-271-750two
>
> If you got the money then both Jim K and Jim B Sell the Quad bag
> system. <http://www.appliedgmc.com/prod.itml/icOid/684>
>
> Mandie, to replace your air system with Gary's plus replacing the air
> bags your total cost is going to be in the $1400 range +/- plus you
> will need to consider labor cost if you cannot do the work yourself.
> The choice will be yours.
>
> Ok, I will get off my soap box now. “
>
> COMMENTS FOR TONIGHT:
> I agree with Todd’s email comments below. I have always had a coaches that have had operating air ride systems. Our 77 Eleganza II (our first coach) ( EL 1 )was a dream to drive, it was a true 2 finger on the steering wheel going down the road coach. The stretch coach built in 1997 also is a EL 1 system and I spent the time finally this fall to do the ride hight correctly and it drove very well out to Tucson and back this year almost 5800 miles total. It does have a few small air leaks that cause it to leak down air pressure over several days, but I will be going thru that this summer and will photo document that. I also have a complete EL 1 system that I bought GMCREC in Houston a few years back that will be going into the 1975 Avion to replace the Power Level system. I will be doing that because I can.
>
> As for level control weight DOES MAKE A DIFFERENCE. When I finally set the ride height this past fall ( it was off quite a bite both front and rear ) the coach weighed empty about 12,100#, now remember I have a stretch which weights more than the standard 26’. My going down the road with everything in the coach, including the kitchen sink, remember that we are going out for 3+ months, plus full fuel tanks ( 75 gallons ), 1/4 full water and basically empty holding tanks, I have 2 tanks, comes in at about 14,800# without passengers. The ride height between empty and loaded after settling was under a 1/4 inch. My system works pretty good, and I did check the coach tonight in the shop and there was no real difference between the fall 2013 and tonights measurements, empty weight measurement. I have air system pressure gauges that show supply and both left and right air pressure in the air bags. The pressure goes up almost 10# each side for the difference between empty and fully loaded weights.
>
> I have had air bag extenders on my 77 Eleganza II coach, but I noticed that the coach road too soft for me and swayed more, I took them off in 1999 and sold them. I have another set for sale ( New ) if anyone want them. They were very popular in the late 80’s and most of the 90’s. They did reduce the air pressure required. Now Todds new style Sullybag air bag system does also reduce the air pressure in the bags, but that is because of the size ( volume )of the bag that is used and it requires less air pressure for the same spring rate as the OEM bag actually giving it a more stable ride. Our stretch coach has a Buskirk designed 4 bags system ( All Buskirk Stretch coaches have the same system ). It is an upgraded version of Leigh Harrison's 4 bag system, but built out of considerable heavier materials and slightly larger air bags and doesn’t have the issues that the stock Harrison system has. It has a very stable ride going down the road.
>
> Again all comments are welcome and we can discuss them all.
>
> JR Wright
> GMC Great Laker MHC
> GMC Eastern States
> GMCMHI
> 78 GMC Buskirk 30’ Stretch
> 1975 GMC Avion (Under Reconstruction)
> Michigan
>
>> On Apr 21, 2014, at 10:26 PM, Todd Sullivan <sgltrac@gmail.com> wrote:
>>
>> Air pressure or lack thereof dictates the height. End of story. The amount of air pressure required to attain a given height will be dictated by type of suspension and loaded weight. The variance in typical loaded weight will not vary much in comparison to total weight supported by the airbags. Therefore once a coach is set with wireless carrying a typical load it is safe to say that the preset pressure will be adequate for a period of time assuming full water tank and 50% fuel since it seems that full tanks transform into half full before the gas station is out of sight and fresh water doesn't leave until waste tanks are empty. To keep an eye on things it would be a good idea to check the "calibration" once in awhile by commanding the preset and quick measure of the result to see if the selected pressure is still adequate. If I have a properly functioning oem system ( as I do) obviously that is better. I you are faced with replacement of many expensive parts and much mecha
>> nical labor to get the current "automatic" system functional I see no other option then the wireless if you don't want to be eyeballing your coach rear suspension in parking lots and gas stations playing hose monkey scurrying around before the air machine shuts off
>>
>> Bring lots o quarters.
>>
>> Todd Sullivan
>>
>> Sully
>> 77 royale
>> Seattle
>>
>>> On Apr 21, 2014, at 6:25 PM, Work Jerry <glwork@mac.com> wrote:
>>>
>>> Hi Kerry,
>>>
>>> This one has been discussed a number of times before. Turns out there is enough hysteresis in the rear suspension that air pressure does represent a very close analog for ride height. It won't be perfect in all cases, but it will be spot on for the majority of cases. When we purchased the Royale more than a decade ago one air pump was bad so I ran with Schrader valves in the ends of the bags "until I got around to fixing it" Years later I never had and never found the need. I could determine quite quickly what pressure resulted in my coach being at correct ride height going down the road. From a full fuel load to an empty one, from a full water load to an empty tank, from full to empty holding tanks the ride height at a given pressure in the bags changed very little, less than the slop in the factory ride height mechanism (factory spec is +- 3/8" if the ride height mechanism is working perfectly). Interesting that the factory ride height spec is +- 1/4" so it was alw
>> ay
>>> s curious to me how one was supposed to stay within that ride height when it was being controlled by a gizmo with an even greater tolerance. But, that is how it is/was. As an experiment, measure your ride height and then have four people stand on the back bumper and measure it again and see how little difference there is.
>>>
>>> Anyway, when I first heard about the wireless air system I jumped on it just to keep my head and body away from the bag as I blew it up or let it down to level. I always felt a bit uneasy being so close to a decades old air bag with close to 100 pounds of air in it. Since I installed the wireless air controller (I put on bag extenders to lower the op pressure to 75psi for my coach going down the road) I find it very convenient and ride height very stable and predictable. I have a stock system on the Clasco and can't find a nickles worth of difference between them in real world use.
>>>
>>> Hope this helps.
>>>
>>> Jerry
>>> Jerry Work
>>> The Dovetail Joint
>>> Fine furniture designed and hand crafted in the 1907 former Masonic Temple building in historic Kerby, OR
>>> Visitors always welcome!
>>> glwork@mac.com
>>> http://jerrywork.com
>>> ++++++++++++++++
>>> Message: 1
>>> Date: Mon, 21 Apr 2014 14:17:47 -0500
>>> From: Kerry Pinkerton <Pinkertonk@MCHSI.com>
>>> Subject: Re: [GMCnet] C
>>> To: gmclist@temp.gmcnet.org
>>> Message-ID: <3c90d.53556edb@gmc.mybirdfeeder.net>
>>> Content-Type: text/plain; charset="ISO-8859-15"
>>>
>>>
>>>
>>> Perhaps I'm missing something but how does the wireless system know what the correct height is? Bag pressure is not the same thing as ride height.
>>> --
>>> Kerry Pinkerton
>>>
>>> North Alabama, near Huntsville,
>>>
>>> 77 Eleganza II, "The Lady", 403CI, also a 76 Eleganza being re-bodied as an Art Deco car hauler
>>> +++++++++++++++
>>>
>>>
>>>
>>>
>>>
>>> _______________________________________________
>>> GMCnet mailing list
>>> Unsubscribe or Change List Options:
>>> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
>> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
> _______________________________________________
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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] Replacing air bag system [message #248144 is a reply to message #248141]

Tue, 22 April 2014 01:35

Guy Lopes

Messages: 499
Registered: April 2004
Location: Sacramento, CA

Karma: 3

Senior Member

Yep! I just did that today. Great talking with you Todd (Sully?). I can't wait to install my new SullyBilt kit and eliminate one of my GMC worries. The rest of my system is in great working order, but I did order the Schrader/cutoff valve assemblies as well.

Guy Lopes
76 Birchaven "Orion"
Sacramento, CA
W6TOL

www.GMC-Guy.com

-----Original Message-----
From: gmclist-bounces@temp.gmcnet.org [mailto:gmclist-bounces@temp.gmcnet.org] On Behalf Of Todd Sullivan
Sent: Monday, April 21, 2014 11:31 PM
To: gmclist@temp.gmcnet.org
Cc: GMC Net
Subject: Re: [GMCnet] Replacing air bag system

The Sullybilt kit is $400 in hot dip galvanized finish or $375 plain steel for those who want to powder coat or paint. (Powder coated kits look pretty bad ass I think). Bags not supplied with kit due to duplicate shipping of bags from me to you adds more cost than if you purchase direct. Current fi 9294 cost is $125 -$139 each. Shut off w Schrader valves add $70 with no additional shipping if ordered same time as kit ( fits in flat rate usps box kit is in)

Check out your bags then check out www.bdub.net/sully/ then call if you have questions.
2 oh 6 948 five 210

Todd Sullivan

Sully
77 royale
Seattle

> On Apr 21, 2014, at 9:54 PM, John Wright <powerjon@chartermi.net> wrote:
>
> Back in June of 2012 we went thru this same discussion and my comment I made then are still the same for today. The same player then, the same players now. More comments at the end.
>
> “June 19, 2012
>
> Gene, Jim, Mandie and others,
>
> This is not meant to be pissing contest on the merits of various air
> systems, lets just get some of the Myths cleared up.
>
> First of all let us agree that the best air ride system for your GMC
> is the factory OEM automatic leveling air ride system, wether it be
> Power-Level, EL 1 or EL 2. If you have one that is working, by all
> means keep it in good shape or have it repaired or renewed if you can.
> If you have never had a coach with a working OEM system then you then
> the comparison will be difficult.
>
> OK, what else is available for our coaches:
>
> 1. Schraders valve and manually putting air in your air bags. Will get
> you coach down the road, but is a real PITA!
>
> 2. Bovee’s Wireless air System
> <http://www.appliedgmc.com/prod.itml/icOid/1382>
>
> It is a well engineered substitute for adding air to your air bags and
> Gary did a great job on designing and assembling this system. It is a
> PRESSURE based system, uses NO leveling valves and is basically the
> same concept as using Schraders valves. (Gary's words paraphrased not
> mine) That said it does have added benefits over just having Schraders
> valves on your air bags.
>
> The following is quoted form Gary's Tech article on the GMC Western
> States site. <http://gmcws.org/Tech/Wireless_air.pdf>
>
> (Quote)
> a. No more having to go to the bags to fill or release air; b. No more
> having to drag out a compressor to air up your bags for travel.
> c. You program the remote digital controller for the proper ride
> height and it will automatically keep the bag’s air pressure within
> plus or minus 3 pounds of the Programmed setting for each bag.
> d. The nice thing is when you park at an RV park or are dry camping
> you use the remote to level your coach.
> e. When you are ready to hit the road you just push the programmed
> button for road travel. It adds or releases air, whatever is needed
> for each bag and you are soon on your way. (This system has a maximum
> air pressure limit of 100 pound.)"
> (UnQuote)
>
> Allows you to manual adjust the air pressure in your air bags. (a,b &
> d) Allows you to automatically return to a predetermined pressure set
> point and hold that pressure +/- 3 PSIG. (c & e)
>
> What it does not do is that it DOES NOT automatically compensate for
> changes in ride height wether setting stationary or rolling down the
> road and your ride height is constantly changing and that can affect
> how your coach steers down the road. You STILL have to check the ride
> height of your coach to determine the necessary predetermined pressure
> requirements for various load conditions the system must compensate
> for. Be sure to let it settle between changes to see if the ride
> height stabilizes and your good to go at that PSIG. Jerry Work says
> this is extremely important when setting right heights both front and
> rear in his alignment presentation he gave at the GMCWS Spring 2012
> rally. (available at jerrywork.com see links at bottom of page) 90% of
> the coaches that attended the rally drove in with the ride heights
> incorrectly set!
>
> System Replacement Cost
>
> To repair the OEM system is very hard to determine and it could be
> from several hundred dollars to considerably more. Depends if you what
> to keep the OEM system.
>
> The cost for Gary's system is going to be in the $780 range depending
> on what you buy or substitute. It is cost effective!
>
> Which is best, it is going to come down to personal choice.
>
> As for Single air Bag per side replacement there are several choices
> available.
>
> SullyBilt - You're looking at about $600 depending on the finish you
> choose on the mounting brackets and that includes air bags cost which
> you purchase yourself. People have found the bags between $110 & $140.
> Just need to shop well. <http://www.bdub.net/sully/>
>
> Jim K sells a replacement bag system call MONO bags for $690 for the
> pair and only for the standard size tire. Well priced system and bolt
> on also. <http://www.appliedgmc.com/prod.itml/icOid/1037>
>
> Zeb Frady @ Southland RV also sells a single bag upgrade.
> 770-271-750two
>
> If you got the money then both Jim K and Jim B Sell the Quad bag
> system. <http://www.appliedgmc.com/prod.itml/icOid/684>
>
> Mandie, to replace your air system with Gary's plus replacing the air
> bags your total cost is going to be in the $1400 range +/- plus you
> will need to consider labor cost if you cannot do the work yourself.
> The choice will be yours.
>
> Ok, I will get off my soap box now. “
>
> COMMENTS FOR TONIGHT:
> I agree with Todd’s email comments below. I have always had a coaches that have had operating air ride systems. Our 77 Eleganza II (our first coach) ( EL 1 )was a dream to drive, it was a true 2 finger on the steering wheel going down the road coach. The stretch coach built in 1997 also is a EL 1 system and I spent the time finally this fall to do the ride hight correctly and it drove very well out to Tucson and back this year almost 5800 miles total. It does have a few small air leaks that cause it to leak down air pressure over several days, but I will be going thru that this summer and will photo document that. I also have a complete EL 1 system that I bought GMCREC in Houston a few years back that will be going into the 1975 Avion to replace the Power Level system. I will be doing that because I can.
>
> As for level control weight DOES MAKE A DIFFERENCE. When I finally set the ride height this past fall ( it was off quite a bite both front and rear ) the coach weighed empty about 12,100#, now remember I have a stretch which weights more than the standard 26’. My going down the road with everything in the coach, including the kitchen sink, remember that we are going out for 3+ months, plus full fuel tanks ( 75 gallons ), 1/4 full water and basically empty holding tanks, I have 2 tanks, comes in at about 14,800# without passengers. The ride height between empty and loaded after settling was under a 1/4 inch. My system works pretty good, and I did check the coach tonight in the shop and there was no real difference between the fall 2013 and tonights measurements, empty weight measurement. I have air system pressure gauges that show supply and both left and right air pressure in the air bags. The pressure goes up almost 10# each side for the difference between empty and fully loaded weights.
>
> I have had air bag extenders on my 77 Eleganza II coach, but I noticed that the coach road too soft for me and swayed more, I took them off in 1999 and sold them. I have another set for sale ( New ) if anyone want them. They were very popular in the late 80’s and most of the 90’s. They did reduce the air pressure required. Now Todds new style Sullybag air bag system does also reduce the air pressure in the bags, but that is because of the size ( volume )of the bag that is used and it requires less air pressure for the same spring rate as the OEM bag actually giving it a more stable ride. Our stretch coach has a Buskirk designed 4 bags system ( All Buskirk Stretch coaches have the same system ). It is an upgraded version of Leigh Harrison's 4 bag system, but built out of considerable heavier materials and slightly larger air bags and doesn’t have the issues that the stock Harrison system has. It has a very stable ride going down the road.
>
> Again all comments are welcome and we can discuss them all.
>
> JR Wright
> GMC Great Laker MHC
> GMC Eastern States
> GMCMHI
> 78 GMC Buskirk 30’ Stretch
> 1975 GMC Avion (Under Reconstruction)
> Michigan
>
>> On Apr 21, 2014, at 10:26 PM, Todd Sullivan <sgltrac@gmail.com> wrote:
>>
>> Air pressure or lack thereof dictates the height. End of story. The
>> amount of air pressure required to attain a given height will be
>> dictated by type of suspension and loaded weight. The variance in
>> typical loaded weight will not vary much in comparison to total
>> weight supported by the airbags. Therefore once a coach is set with
>> wireless carrying a typical load it is safe to say that the preset
>> pressure will be adequate for a period of time assuming full water
>> tank and 50% fuel since it seems that full tanks transform into half
>> full before the gas station is out of sight and fresh water doesn't
>> leave until waste tanks are empty. To keep an eye on things it would
>> be a good idea to check the "calibration" once in awhile by
>> commanding the preset and quick measure of the result to see if the
>> selected pressure is still adequate. If I have a properly functioning
>> oem system ( as I do) obviously that is better. I you are faced with
>> replacement of many expensive parts and much mecha nical labor to get
>> the current "automatic" system functional I see no other option then
>> the wireless if you don't want to be eyeballing your coach rear
>> suspension in parking lots and gas stations playing hose monkey
>> scurrying around before the air machine shuts off
>>
>> Bring lots o quarters.
>>
>> Todd Sullivan
>>
>> Sully
>> 77 royale
>> Seattle
>>
>>> On Apr 21, 2014, at 6:25 PM, Work Jerry <glwork@mac.com> wrote:
>>>
>>> Hi Kerry,
>>>
>>> This one has been discussed a number of times before. Turns out
>>> there is enough hysteresis in the rear suspension that air pressure
>>> does represent a very close analog for ride height. It won't be
>>> perfect in all cases, but it will be spot on for the majority of
>>> cases. When we purchased the Royale more than a decade ago one air
>>> pump was bad so I ran with Schrader valves in the ends of the bags
>>> "until I got around to fixing it" Years later I never had and never
>>> found the need. I could determine quite quickly what pressure
>>> resulted in my coach being at correct ride height going down the
>>> road. From a full fuel load to an empty one, from a full water load
>>> to an empty tank, from full to empty holding tanks the ride height
>>> at a given pressure in the bags changed very little, less than the
>>> slop in the factory ride height mechanism (factory spec is +- 3/8"
>>> if the ride height mechanism is working perfectly). Interesting
>>> that the factory ride height spec is +- 1/4" so it was alw
>> ay
>>> s curious to me how one was supposed to stay within that ride height when it was being controlled by a gizmo with an even greater tolerance. But, that is how it is/was. As an experiment, measure your ride height and then have four people stand on the back bumper and measure it again and see how little difference there is.
>>>
>>> Anyway, when I first heard about the wireless air system I jumped on it just to keep my head and body away from the bag as I blew it up or let it down to level. I always felt a bit uneasy being so close to a decades old air bag with close to 100 pounds of air in it. Since I installed the wireless air controller (I put on bag extenders to lower the op pressure to 75psi for my coach going down the road) I find it very convenient and ride height very stable and predictable. I have a stock system on the Clasco and can't find a nickles worth of difference between them in real world use.
>>>
>>> Hope this helps.
>>>
>>> Jerry
>>> Jerry Work
>>> The Dovetail Joint
>>> Fine furniture designed and hand crafted in the 1907 former Masonic
>>> Temple building in historic Kerby, OR Visitors always welcome!
>>> glwork@mac.com
>>> http://jerrywork.com
>>> ++++++++++++++++
>>> Message: 1
>>> Date: Mon, 21 Apr 2014 14:17:47 -0500
>>> From: Kerry Pinkerton <Pinkertonk@MCHSI.com>
>>> Subject: Re: [GMCnet] C
>>> To: gmclist@temp.gmcnet.org
>>> Message-ID: <3c90d.53556edb@gmc.mybirdfeeder.net>
>>> Content-Type: text/plain; charset="ISO-8859-15"
>>>
>>>
>>>
>>> Perhaps I'm missing something but how does the wireless system know what the correct height is? Bag pressure is not the same thing as ride height.
>>> --
>>> Kerry Pinkerton
>>>
>>> North Alabama, near Huntsville,
>>>
>>> 77 Eleganza II, "The Lady", 403CI, also a 76 Eleganza being
>>> re-bodied as an Art Deco car hauler
>>> +++++++++++++++
>>>
>>>
>>>
>>>
>>>
>>> _______________________________________________
>>> GMCnet mailing list
>>> Unsubscribe or Change List Options:
>>> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
>> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
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Guy Lopes 76 Birchaven "Orion" Sacramento, CA W6TOL www.GMC-Guy.com

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