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[GMCnet] Are there tutorials for hooking up air lines to bags and compressors? [message #128174] Wed, 01 June 2011 11:25 Go to next message
Robin Hood is currently offline  Robin Hood   United States
Messages: 1078
Registered: April 2011
Karma: 3
Senior Member
My two compressors are not connected to my bags, which have some kind
of valve (what I assume to be Schraders?) to inflate them. One bag
holds air, the other one deflates after two days. They're old and need
replacing with something in any case. I'm going to be doing this
myself and I've never messed with air systems before. Are there any
helpful youtube videos or websites or even a good book that tells how
ot go about connecting this stuff together? I want to have an idea
what I'm getting into?

--
Robin Hood
Jackson, MS
2003 Buick Lesabre
1968 Pontiac Catalina
1978 GMC Royale motorhome
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Re: [GMCnet] Are there tutorials for hooking up air lines to bags and compressors? [message #128186 is a reply to message #128174] Wed, 01 June 2011 13:06 Go to previous messageGo to next message
GeorgeRud is currently offline  GeorgeRud   United States
Messages: 1380
Registered: February 2007
Location: Chicago, IL
Karma: 0
Senior Member
Can't find any videos that would be of help, but the air-lines are pretty much the same as those used on heavy trucks, so any local shop that works on trucks should be able to help you. Most of the fittings are push-on types, where the line simply fits into the fitting. Jim Bounds has some fittings listed on his GMC Coop site that appear to be more secure and may be a better way to go, but I think most have just used the usual DOT approved line and fittings.

If you want, check out the McMaster-Carr website for the hose and fittings. Jusst be sure to use the DOT approved ones. The routing and connection instructions should be available in the repair manuals (or on the DVDs).

Good Luck with your project!


George Rudawsky
Chicago, IL
75 Palm Beach
Re: [GMCnet] Are there tutorials for hooking up air lines to bags and compressors? [message #128201 is a reply to message #128186] Wed, 01 June 2011 14:40 Go to previous messageGo to next message
John Sharpe is currently offline  John Sharpe   United States
Messages: 489
Registered: February 2006
Location: Texas
Karma: 1
Senior Member
The '78's came with two different leveling systems. Electro-level and Electro-level II. You indicate that you have two compressors which suggests that you have the Electro-level II system. As far as air lines go it is real simple. One air line from on compressor to the right air bag and another air line from the second compressor to the left air bag. The Electro-level II system uses electronic height control sensors. The parts are readily available and this system can be fixed to operate as it was originally designed. Send me a private message to my e-mail if you would like more information or documentation.

John Sharpe
Humble,TX
'78 Eleganza TBI
'89 Spectrum 2000 MPI V-10
'40 Ford Panel Delivery TPI
johnasharpe@gmail.com
Re: [GMCnet] Are there tutorials for hooking up air lines to bags andcompressors? [message #128234 is a reply to message #128174] Wed, 01 June 2011 20:11 Go to previous messageGo to next message
USAussie is currently offline  USAussie   United States
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
Senior Member
Robin,

There is a TERRIFIC book that shows you all about the rear suspension: it's called the Maintenance Manual! ;-)

You need X-7725 which can be downloaded here:

http://www.bdub.net/factory-manuals.html

Once you download it turn to page 4B-1 - 1978 Rear Suspension. There are 21 pages of information.

After studying the manual I suggest you find someone close to you that has a GMC with the ELII system that is hooked up correctly and works. Take your camera / video and have them show you how their system is wired and plumbed so you can film it.

Come to think of it you might want to consider joining the Dixielanders GMC Club and attending:

Dixielanders Summer Rally

14 – 17 Jul 2011 (Thursday - Sunday)

Where: Gadsden, Alabama

Description: Noccalula Falls

http://www.gmcd​ixielanders.org​/events/index.h​tml

Go with or without your coach; I can assure you that there will be LOTS of people there that will be more than happy to help you and you will probably learn more about your coach in three days than you can believe.

Regards,
Rob M.
USAussie - Downunder
AUS '75 Avion - The Blue Streak TZE365V100428
USA '75 Avion - Double Trouble TZE365V100426


-----Original Message-----
From: gmclist-bounces@temp.gmcnet.org [mailto:gmclist-bounces@temp.gmcnet.org] On Behalf Of Robin Hood
Sent: Thursday, June 02, 2011 2:26 AM
To: gmclist@temp.gmcnet.org
Subject: [GMCnet] Are there tutorials for hooking up air lines to bags andcompressors?

My two compressors are not connected to my bags, which have some kind
of valve (what I assume to be Schraders?) to inflate them. One bag
holds air, the other one deflates after two days. They're old and need
replacing with something in any case. I'm going to be doing this
myself and I've never messed with air systems before. Are there any
helpful youtube videos or websites or even a good book that tells how
ot go about connecting this stuff together? I want to have an idea
what I'm getting into?

--
Robin Hood
Jackson, MS
2003 Buick Lesabre
1968 Pontiac Catalina
1978 GMC Royale motorhome
_______________________________________________
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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
Re: [GMCnet] Are there tutorials for hooking up air lines to bags and compressors? [message #128264 is a reply to message #128174] Thu, 02 June 2011 00:47 Go to previous messageGo to next message
mike miller   United States
Messages: 3576
Registered: February 2004
Location: Hillsboro, Oregon
Karma: 0
Senior Member
Robin Hood wrote on Wed, 01 June 2011 09:25

My two compressors are not connected to my bags, which have some kind
of valve (what I assume to be Schraders?) to inflate them. One bag
holds air, the other one deflates after two days. They're old and need
replacing with something in any case. I'm going to be doing this
myself and I've never messed with air systems before. Are there any
helpful youtube videos or websites or even a good book that tells how
ot go about connecting this stuff together? I want to have an idea
what I'm getting into?


Robin,

I know you do not want to spend more than you need to... at least right away anyway...

Have you checked the one "bad" bag for leaks? It might not be as bad as you think. It could be leaking at the tank valve or O-ring just inside that end. All it takes is your portable air compressor and some 'leak detector fluid' (soapy water).

I do not see the confusion about your air lines. You only have two... and they are not that long... from the airbag to the valve next to the pump. What is the issue?

OBTW: What is wrong with the current lines? (Other than someone disconnected them from the bags and installed tank valves in the bags?) Once your bags hold air, remove the tank valves and connect the lines. (You may want to do the next step first...)

Do your air pumps run? They do not need to be connected to the bags to check this step. You may want to test the system "a little bit" before pulling the tank valves from the airbags. I suspect that someone put the tank valves in the bags to avoid looking at the air system. The electrical side, mostly for travel mode, is the hard part of the EL2 system. Fixed properly, it is a good system.


Mike Miller -- Hillsboro, OR -- on the Black list
(#2)`78 23' Birchaven Rear Bath -- (#3)`77 23' Birchaven Side Bath
More Sidekicks than GMC's and a late model Malibu called 'Boo' http://m000035.blogspot.com
Re: [GMCnet] Are there tutorials for hooking up air lines to bags and compressors? [message #128267 is a reply to message #128264] Thu, 02 June 2011 05:34 Go to previous messageGo to next message
Mr ERFisher is currently offline  Mr ERFisher   United States
Messages: 7117
Registered: August 2005
Karma: 2
Senior Member
here are some trouble shooting tips for el systems
http://gmcmotorhome.info/levelsch.htm#el

gene

On Wed, Jun 1, 2011 at 10:47 PM, Mike Miller <m000035@gmail.com> wrote:

>
>
> Robin Hood wrote on Wed, 01 June 2011 09:25
> > My two compressors are not connected to my bags, which have some kind
> > of valve (what I assume to be Schraders?) to inflate them. One bag
> > holds air, the other one deflates after two days. They're old and need
> > replacing with something in any case. I'm going to be doing this
> > myself and I've never messed with air systems before. Are there any
> > helpful youtube videos or websites or even a good book that tells how
> > ot go about connecting this stuff together? I want to have an idea
> > what I'm getting into?
>
>
> Robin,
>
> I know you do not want to spend more than you need to... at least right
> away anyway...
>
> Have you checked the one "bad" bag for leaks? It might not be as bad as
> you think. It could be leaking at the tank valve or O-ring just inside that
> end. All it takes is your portable air compressor and some 'leak detector
> fluid' (soapy water).
>
> I do not see the confusion about your air lines. You only have two... and
> they are not that long... from the airbag to the valve next to the pump.
> What is the issue?
>
> OBTW: What is wrong with the current lines? (Other than someone
> disconnected them from the bags and installed tank valves in the bags?)
> Once your bags hold air, remove the tank valves and connect the lines.
> (You may want to do the next step first...)
>
> Do your air pumps run? They do not need to be connected to the bags to
> check this step. You may want to test the system "a little bit" before
> pulling the tank valves from the airbags. I suspect that someone put the
> tank valves in the bags to avoid looking at the air system. The electrical
> side, mostly for travel mode, is the hard part of the EL2 system. Fixed
> properly, it is a good system.
> --
> Mike Miller -- Hillsboro, OR -- on the Black list
> (#1)'73 26' exPainted D. -- (#2)`78 23' Birchaven Rear Bath -- (#3)`77 23'
> Birchaven Side Bath
> http://m000035.blogspot.com
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>



--
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] Are there tutorials for hooking up air lines to bags and compressors? [message #128273 is a reply to message #128267] Thu, 02 June 2011 06:49 Go to previous messageGo to next message
John Sharpe is currently offline  John Sharpe   United States
Messages: 489
Registered: February 2006
Location: Texas
Karma: 1
Senior Member
There are only two air lines. One from each compressor to their corresponding air bag. The lines hook to the 'Shut-Off Solenoid Valves'. The blue air line goes to right bag and the grey air line goes to the left air bag. These valves were installed backwards from the factory and should be turned around if there is a problem with them leaking down. Again, contact me direct if you would like additional information.

John Sharpe
Humble,TX
'78 Eleganza TBI
'89 Spectrum 2000 MPI V-10
'40 Ford Panel Delivery TPI
johnasharpe@gmail.com
Re: [GMCnet] Are there tutorials for hooking up air lines to bags and compressors? [message #128279 is a reply to message #128273] Thu, 02 June 2011 07:44 Go to previous messageGo to next message
mike miller   United States
Messages: 3576
Registered: February 2004
Location: Hillsboro, Oregon
Karma: 0
Senior Member
John Sharpe wrote on Thu, 02 June 2011 04:49

... [EL2] The lines hook to the 'Shut-Off Solenoid Valves'. ...

... These valves were installed backwards from the factory and should be turned around if there is a problem with them leaking down. ...


Didn't know that.... I'll have to check my '78. (Even though it doesn't seem to leak down.) Arrow needs to point AWAY from the bag... right???




Mike Miller -- Hillsboro, OR -- on the Black list
(#2)`78 23' Birchaven Rear Bath -- (#3)`77 23' Birchaven Side Bath
More Sidekicks than GMC's and a late model Malibu called 'Boo' http://m000035.blogspot.com
Re: [GMCnet] Are there tutorials for hooking up air lines to bags and compressors? [message #128332 is a reply to message #128279] Thu, 02 June 2011 12:35 Go to previous messageGo to next message
John Sharpe is currently offline  John Sharpe   United States
Messages: 489
Registered: February 2006
Location: Texas
Karma: 1
Senior Member
Ok, from the private messages I have gotten, apparently inquiring minds want to know. The arrow on the hold solenoid valve should point towards the compressor and away from the air bag. The reason for this is that since the EL II system has no air tank the higher pressure is in the air bag. There is a spring in the valve that closes it when the solenoid is not applied. When the valve is installed correctly the pressure in the bag holds the valve closed. If the valve is reversed then the spring in the valve has to overcome the pressure from the bag in order to keep the valve from leaking. All the original set-ups I have seen have the hold solenoid valves mounted backwards. As one would naturally assume, the assembler apparently thought that the arrow indicated flow . The valves have held for 20+ years but some have eventually gotten tired and started to leak through the compressor.

I had one that about 'ate my lunch' until I found Dave Mumert's site http://www.mumert.com/el2000.htm . I turned the valves around and viola, fixed the problem.

On the electrical control side of the ElectroLevel II system or converting your PowerLevel to EL II you could also review this site: http://www.gmcmhphotos.com/photos/showphoto.php?photo=18932&cat=4607


John Sharpe
Humble,TX
'78 Eleganza TBI
'89 Spectrum 2000 MPI V-10
'40 Ford Panel Delivery TPI
johnasharpe@gmail.com
Re: [GMCnet] Are there tutorials for hooking up air lines to bagsand compressors? [message #128375 is a reply to message #128332] Thu, 02 June 2011 17:34 Go to previous message
USAussie is currently offline  USAussie   United States
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
Senior Member
John,

Got it!

And you thought you had retired from teaching auto mechanics! ;-)

Regards,
Rob M.
USAussie - Downunder
AUS '75 Avion - The Blue Streak TZE365V100428
USA '75 Avion - Double Trouble TZE365V100426


-----Original Message-----
From: gmclist-bounces@temp.gmcnet.org
[mailto:gmclist-bounces@temp.gmcnet.org] On Behalf Of John Sharpe
Sent: Friday, June 03, 2011 3:35 AM
To: gmclist@temp.gmcnet.org
Subject: Re: [GMCnet] Are there tutorials for hooking up air lines to
bagsand compressors?

Ok, from the private messages I have gotten, apparently inquiring minds want
to know. The arrow on the hold solenoid valve should point towards the
compressor and away from the air bag. The reason for this is that since the
EL II system has no air tank the higher pressure is in the air bag. There
is a spring in the valve that closes it when the solenoid is not applied.
When the valve is installed correctly the pressure in the bag holds the
valve closed. If the valve is reversed then the spring in the valve has to
overcome the pressure from the bag in order to keep the valve from leaking.
All the original set-ups I have seen have the hold solenoid valves mounted
backwards. As one would naturally assume, the assembler apparently thought
that the arrow indicated flow . The valves have held for 20+ years but some
have eventually gotten tired and started to leak through the compressor.

I had one that about 'ate my lunch' until I found Dave Mumert's site
http://www.mumert.com/el2000.htm . I turned the valves around and viola,
fixed the problem.

On the electrical control side of the ElectroLevel II system or converting
your PowerLevel to EL II you could also review this site:
http://www.gmcmhphotos.com/photos/showphoto.php?photo=18932&cat=4607
--
John Sharpe
Humble,TX
'78 Eleganza TBI
'89 Spectrum 2000 V-10
'40 Ford Deluxe TBI
mailto:johnasharpe@gmail.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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