Reply
 
Thread Tools Search this Thread Display Modes
 
Old 06-07-2012, 05:09 PM   #1
2 Rivet Member
 
1983 31' Airstream310
Brighton , sussex
Join Date: Oct 2011
Posts: 80
310 Rear Airbag control

As most of you know I got my 310 imported at the beginning of the year. Its had alot of work done to make it road worthy. I dont think it handles too well at the momnet despit adjustment of the bell crank, new front anti roll bar bushes, front steering damper, shock and air bags. It's a bit floaty and crashes over bumps at the rear. The compressor has worked only once but I do not think it is working correctly. I know that it only fills the rear bags when it is fully loaded or has been sitting for a long time.
Is there a fuse in the front fuse box what rating and where is it?
I want to monitor the pressure on the dash eventually, fill the tyres and run some air horns!
I might need to install another compressor and tank for the front but it can wait. Just some advice needed on getting it to work properly. Oh yes...what pressure should the rear air bags be inflated to and would I have to get a pressure switch that cycles to this pressure?

D
__________________

__________________
Loving Life, Chicks, Cars and Mummas Grits baby
montreal is offline   Reply With Quote
Old 06-07-2012, 05:18 PM   #2
Full Timers/Diesel power.
 
Mike Leary's Avatar
 
1983 31' Airstream310
Cactus Hug , Arizona
Join Date: Mar 2007
Posts: 2,540
Images: 11
First things first: When the compressor has finished pumping,the rear air bags should measure 10" from the top of the air bag support beam to the bottom of the main frame chassis rail. It will vary side to side, but not more than 1/4". There is no compressor connection for the fronts.
__________________

__________________
"A settled wisdom, plus the itch to be elsewhere"
Mike Leary is offline   Reply With Quote
Old 06-07-2012, 05:42 PM   #3
Rivet Master
 
1974 Argosy 20
2014 20' Flying Cloud
Kooskia , Idaho
Join Date: Jul 2009
Posts: 4,591
From memory (I sold my 310 a few years ago) the tank pressure ran about 95# and the bag pressure, when level, about 70#. I never paid much attention to the bag pressure as once the automatic height level was happy all worked fine.

I did run a separate 12 volt line (fused) from the battery compartment to the back compressor compartment, to supply a relay there which sent the 12 volts directly to the compressor. That way there was minimum voltage drop to the compressor and it ran shorter times and cooler. The coil of the relay was fed by the original line from the motorhome, which is switched by the ignition circuit. It has significant voltage drop issues, but feeding the relay coil was within it's capacity.

I put an electric pressure gauge sending unit with a gauge under the dash, 0 - 100# so I could monitor the tank pressure. I hooked it into the air line which has the pressure switch attached to it so it measured the tank pressure. It was a common oil pressure gauge and sending unit, so fairly inexpensive. A red light on the dash, in parallel with the compressor motor told me when it came on and how long it ran.
__________________
idroba is offline   Reply With Quote
Old 06-07-2012, 05:50 PM   #4
Full Timers/Diesel power.
 
Mike Leary's Avatar
 
1983 31' Airstream310
Cactus Hug , Arizona
Join Date: Mar 2007
Posts: 2,540
Images: 11
It's interesting (not) how most of us have had to re-do so many things on a coach that was was "top-of-the-line".
__________________
"A settled wisdom, plus the itch to be elsewhere"
Mike Leary is offline   Reply With Quote
Old 06-07-2012, 11:01 PM   #5
Rivet Master
 
Smartstream's Avatar

 
1982 28' Airstream 280
Port Angeles , Washington
Join Date: Aug 2008
Posts: 1,371
Like idroba suggests run a separate line through a relay to power the compressor. It will live longer and be happier. As Mike says the leveling valve controls the height of the air bags and also the ride height of the coach. Mine has a gauge on the dash that shows the pressure in the bags rather than the tank pressure. You can watch the pressure vary as you go over bumps. The is a delay built into the original valve so that it doesn't change pressure in the bags unless the ride height changes for about 15 seconds. This way the compressor doesn't cycle every time you hit a little bump. I run the tank pressure at 100 psi. and normally the bags run at about 75 psi. You can actually see the bag pressure go up a few lbs. as the holding tanks in the back fill up.
The system was made by this outfit American Carrier Equipment - American Carrier Equipment, Inc. Home
They still have parts and info on the system. The compressor, bags and leveling valve are common and can be found at truck supplies.

Good luck, Dan
__________________
Smartstream is offline   Reply With Quote
Old 06-10-2012, 07:21 AM   #6
2 Rivet Member
 
1983 31' Airstream310
Brighton , sussex
Join Date: Oct 2011
Posts: 80
Thanks. I have replaced a 30 amp fuse in the fusebox which was connected to the compressor. There is also a loose wire on the on-off switch thats in the compartment. The switch is the same as the one fitted on my spray gun compressor tank with a red push-pull knob. Idroba says "I did run a separate 12 volt line (fused) from the battery compartment to the back compressor compartment, to supply a relay there which sent the 12 volts directly to the compressor." What size wire did you use? You guys have AWG wire sizes I think what size is this in our good Queens English??!!
Could I just use an air line and a check valve going to a pressure gauge on the dash?
My mechanic told me it is set to 100PSI also. The tank took about 7-10 mins to fill and cut off with the engine not running. Is this normal? The bags came up with about an inch of the tapered metal mounting now showing at the bottom.
I will measure for the magic 10" but I read that the arm can be bent or rotated to achieve 'more fill' to get the height right. The fronts have remote lines fixed to the sides of the banana wraps that I just pumped up by hand to 60 psi. I read that stock is 50PSi but I think a little firmer wouldnt hurt. They were set to 50 and 30 which cant have helped the handling.Any thoughts
__________________
Loving Life, Chicks, Cars and Mummas Grits baby
montreal is offline   Reply With Quote
Old 06-10-2012, 09:59 AM   #7
Rivet Master
 
Smartstream's Avatar

 
1982 28' Airstream 280
Port Angeles , Washington
Join Date: Aug 2008
Posts: 1,371
Quote:
Originally Posted by montreal View Post
Thanks. I have replaced a 30 amp fuse in the fusebox which was connected to the compressor. There is also a loose wire on the on-off switch thats in the compartment. The switch is the same as the one fitted on my spray gun compressor tank with a red push-pull knob. Idroba says "I did run a separate 12 volt line (fused) from the battery compartment to the back compressor compartment, to supply a relay there which sent the 12 volts directly to the compressor." What size wire did you use? You guys have AWG wire sizes I think what size is this in our good Queens English??!!
Could I just use an air line and a check valve going to a pressure gauge on the dash?
My mechanic told me it is set to 100PSI also. The tank took about 7-10 mins to fill and cut off with the engine not running. Is this normal? The bags came up with about an inch of the tapered metal mounting now showing at the bottom.
I will measure for the magic 10" but I read that the arm can be bent or rotated to achieve 'more fill' to get the height right. The fronts have remote lines fixed to the sides of the banana wraps that I just pumped up by hand to 60 psi. I read that stock is 50PSi but I think a little firmer wouldnt hurt. They were set to 50 and 30 which cant have helped the handling.Any thoughts
I don't know the Queens wire size but the wire running the compressor now works but just go up a size or two and you should be fine. You are just trying to minimize voltage drop over the long wire run.

You can just run an air line to the dash for a gauge but no check valve. With a check valve you wouldn't see a pressure drop. There is a check valve at or near the compressor. This protects the compressor from hard starting against pressure.

I installed this compressor VIAIR Corporation - 450C IG Part No. 45050 45058 It may be a little overkill but it fills the tank in a little over a minute and as you can see has a 100% duty cycle at 100 psi.

The leveling valve is located on the cross member above the air bags. There is a nut on the arm that allows you to adjust the arm on the valve to adjust the height. If it's the original valve there should be a 10 to 15 second delay. When you adjust the valve give it a little time to react.

I've heard the front bags are supposed to be at 55 psi. so you are in the proper range.

Good luck, Dan
__________________
Smartstream is offline   Reply With Quote
Old 06-10-2012, 10:18 AM   #8
Full Timers/Diesel power.
 
Mike Leary's Avatar
 
1983 31' Airstream310
Cactus Hug , Arizona
Join Date: Mar 2007
Posts: 2,540
Images: 11
The front coil springs on the P-30 were way undersized for the weight of the coaches, especially the diesel, so the bags were installed. I would find a flat surface and measure from ground to the fender trim on all four corners, this should give you an idea of any changes needed to the front or rear bags. A front end alingment should be considered, but over there, guys might not be familiar with the P-30.
I also ran 60 psi on the front bags, with new springs, I no longer use them.
__________________
"A settled wisdom, plus the itch to be elsewhere"
Mike Leary is offline   Reply With Quote
Old 06-10-2012, 10:23 AM   #9
Rivet Master
 
1974 Argosy 20
2014 20' Flying Cloud
Kooskia , Idaho
Join Date: Jul 2009
Posts: 4,591
From the battery to the relay I would use a #10 AWG wire. I don't know other wire size systems but put in something that would carry 30 amps easily. The original feed wire to the compressor would then just be used to operate the coil in the relay, a very small current draw. Yes, the compressor should shut off when the ignition is off. A 7 to 10 minute fill seem a long time to me, indicating either a worn compressor or low voltage to it.

I personally would not run an air line to a gauge on the dash (and no check valve as Dan said) as it is just another source of leaks and potential air loss in case of a break or cut in the line. I had a friend with a 280, and a rock clipped the external fill valve off his air tank, causing complete air pressure loss and flat air bags while he was on the road. It had to be driven a mile or so to a safe place to pull off, with the flat rear air bags. We got it going again with some difficulty, but the air bags leaked and had to be replaced after that event. So, the more possibility for leaks the more issues you could have in the long run. That is why I used an electric sending unit and gauge on mine, and he did the same thing oh his.

BTW, once I got my system sorted out, the compressor ran very very seldom. The rig could sit all winter and in the spring when started, the compressor would not even come on. So, if yours runs a lot, you still have leaks to chase down.
__________________

__________________
idroba is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



Virginia Campgrounds

Reviews provided by




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 07:22 PM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.

Airstream is a registered trademark of Airstream Inc. All rights reserved. Airstream trademark used under license to Social Knowledge LLC.