Air suspension help

[CountryB]

If you have the auto-air-leveling, you would have a control panel on the dash (usually drivers left side panel) with the controls.
HWH is a major supplier of these leveling systems. The panel would look something like this:

[A Traveler]

The Freightliner spec for air system leak-down is a maximum of 2 pounds PER MINUTE! I know this because I asked the Freightliner factory guys at Gaffney. A 120 PSI system would leak down to zero in an hour! I’m sure Spartan’s spec is about the same.

Our coach will leak down to zero PSI in about 36 hours. I have never given it a thought. All works fine.

[LA Dueck]

There is some tolerance for air leakage from the air brakes. When I took the air brakes course, they advised we should be doing a "stand" test before each trip. After running up to between 90 to 100 psi, you would place chock blocks on your wheels and release the air brake. You turn off the engine and then reengage the ignition (don't start the motor). Depress the brake and hold for 1 minute. If you lose less than 3 psi in your tanks you are within acceptable limits. Also, the compressor should be able to get you from 50 to 90 psi in 3 minutes at 1200 rpm. Hope this helps; if you have an air leak, they can be hard to find. I just spent $2500 to find a simple cracked fitting on my compressor tank.

[PPCPilot]

Originally Posted by LA Dueck

There is some tolerance for air leakage from the air brakes. When I took the air brakes course, they advised we should be doing a "stand" test before each trip. After running up to between 90 to 100 psi, you would place chock blocks on your wheels and release the air brake. You turn off the engine and then reengage the ignition (don't start the motor). Depress the brake and hold for 1 minute. If you lose less than 3 psi in your tanks you are within acceptable limits. Also, the compressor should be able to get you from 50 to 90 psi in 3 minutes at 1200 rpm. Hope this helps; if you have an air leak, they can be hard to find. I just spent $2500 to find a simple cracked fitting on my compressor tank.

Thank you. I have left the coach alone for the past 48 hours and it is still aired up. I don't know that I will be chasing anything yet. The system airs up fine and I don't see a loss of air while traveling with the coach. For once in my life maybe I am as close to normal as it gets.

[CoachStreamr]

Originally Posted by A Traveler

The Freightliner spec for air system leak-down is a maximum of 2 pounds PER MINUTE! I know this because I asked the Freightliner factory guys at Gaffney. A 120 PSI system would leak down to zero in an hour! I’m sure Spartan’s spec is about the same.

Our coach will leak down to zero PSI in about 36 hours. I have never given it a thought. All works fine.

Interesting, I wonder if Spartan has a spec like that. Does Freightliner have that spec posted anywhere their site?


Our Coach will lose all air in just over 2 days.


I've read some owners (w/Air Ride) post they have their air system hold air for many many days/weeks.



.

[windsorbill]

Originally Posted by PPCPilot

I need to learn my air pump and bag system better to understand this. Where do they typically put the air pumps on these coaches? In the generator bay? I will try to determine if it has the supplemental pump you all are talking about.

They can be anywhere. Mine happens to be over the steer axle. I've seen them by the tag axle. I have a Valid system, so it might be different than you're, but I can manually raise the coach with the air bags (main engine NOT running) by pushing a button on the Valid system. When I do that, the aux. pump will come on. If you can duplicate that somehow, it's easy to follow the noise.

[PPCPilot]

Originally Posted by CountryB

If you have the auto-air-leveling, you would have a control panel on the dash (usually drivers left side panel) with the controls.
HWH is a major supplier of these leveling systems. The panel would look something like this:

I have an HWH leveling system and I have a panel that looks similar to the one you posted but not the same. I would guess that my coach is NOT auto leveling when the coach is off....at least not to the point of having an auxiliary pump. I suppose it could be like my Land Rover in that it will only dump air to try to level if it thinks it is off.

Thanks for the contribution to our conversation!

[CountryB]

Originally Posted by LA Dueck

After running up to between 90 to 100 psi, you would place chock blocks on your wheels and release the air brake. You turn off the engine and then reengage the ignition (don't start the motor). Depress the brake and hold for 1 minute.
If you lose less than 3 psi in your tanks you are within acceptable limits. Also, the compressor should be able to get you from 50 to 90 psi in 3 minutes at 1200 rpm.

That is a "Brake safety test". It tests the air brake chamber diaphragms, brake valves, and related tubing/hoses for the braking system.
It should be done before every trip.

But that test has nothing to do with the air suspension or leveling system.

[olcarguy]

2000 Newmar Mountain Aire 4093
Cummins 350HP, Spartan chassis



PPCPilot Has a Cummins in a spartan chassis. Therefor it has air breaks and a compressor that is attached to the motor. So you can stop looking for any other compressor. On my Coach I loose all my air in a couple hrs,. However my air bags don't loose any air at all. Sat in my drive all winter and never went down at all.

Good Luck with your new to you Coach. Trust you will find and repair all your issues.

[CoachStreamr]

Originally Posted by LA Dueck

When I took the air brakes course, they advised we should be doing a "stand" test before each trip. After running up to between 90 to 100 psi, you would place chock blocks on your wheels and release the air brake. You turn off the engine and then reengage the ignition (don't start the motor). Depress the brake and hold for 1 minute. If you lose less than 3 psi in your tanks you are within acceptable limits.

Is it ok to do this test on my 1995 Spartan EC-2242 Chassis with Air Ride?


.

[Ray,IN]

Originally Posted by CoachStreamr

Is it ok to do this test on my 1995 Spartan EC-2242 Chassis with Air Ride?


.

That is the industry standard air brake pre-trip test. Air ride is independent of the air brake system, there is a fail-safe mechanism to insure air brakes are isolated from other air systems.

[DENSHER]

Originally Posted by CoachStreamr

Is it ok to do this test on my 1995 Spartan EC-2242 Chassis with Air Ride?


.

Yes you can and should. Our EC2000 chassis have air over hydraulic with only 2 air chambers, 1 each for front and rear master cylinders, but still should be tested for leaks. Note: you may see more than 3 psi drop when first applying the brakes but watch for the drop while holding for 1 minute.

[PPCPilot]

An update to my thread contributors. I was just out to the coach to check things over now that it has sat unattended for over 5 days. The coach is still sitting level and the gauges both show 100 PSI on them yet! I am hopeful that whatever was going on was a hiccup and exercising the system for a few days helped it out.

Time will tell but this problem seems to have gone away so I can focus on other issues at hand.

[CoachStreamr]

What about the air ride height control valves?


I have read about intermittent slow leaks with those with age, replacing one or more of those.


.