Questions about air suspension

[Gimpy]

When my suspension comes up with air is it supposed to vent some air pressure at some point? If so, when and why and if mine doesn't then what should I look into?

[tuga]

Gimpy,

When you first start your engine the air pressure builds up in the brake tanks and also in the air supply tank. After they fill with the maximum amount of air (around 120#) you will hear a pop off valve open and the excess air that the engine compresssor has pumped will be released and the amount of air in the supply tank will go down to about 110 psi or 100 psi.

If your air tanks never reach the full mark (120 psi) you may have a bad air leak.

What year is your coach?

When you turn the engine off how long does it take for the air supply tank to bleed down to zero?

When you turn the engine off how long does it take for the brake tanks to bleed down to zero?

You need to test these and write down the results; then bring the coach to a bus or truck repair shop and have the leaks fixed.

It is imperative that you have good air pressure in your brake tanks before you drive the coach. 90psi at minimum.

[Neweller]

You definitely need to find out if you have a major leak. You should be able to hear it. How high is your air pressure gauge reading after the bags are all the way

up? If your air compressor is running all the time you have a big leak. How long has it been this way? There is a red light on the dash that comes on if you have low air

pressure and if your air hits 45 psi your emergency brakes will come on. Like Tuga is saying, when you reach around 120 psi the blow-off valve will go off with the

sound of a bunch of air. Do the checks Tuga stated let us know or call your local truck/rv/bus repair guy. If it is leaking bad you may have to call a service guy to

come out and do the repair. If that is the case, let us know if you need a referral for your area. If air is coming out constantly I would check the blow-off valves on

the tanks to make sure they are not sticking or dirt got in somehow, I have had that happen more than once over the years. Sometimes they are just wore out.

But unless you know what you are looking for and know how to get under the coach safely, I don't advise trying.


Ken

[NewellCrazy]

the answer is no, it should just ease up and quit letting air into the air bellows. (Air bags.)

[The Newell]

Check the leveling valves, On air suspension, one point that does leak are the leveling valves. They can appear to be sound, but can leak just enough to let down the suspension over night.