Air suspension question

[Vintage]

What pressure should the air bag system be at?
My suspension starts to fill at 70lbs and is at ride height at about 90lbs.

The brake system goes on up to 125lbs. Does this mean that the air bags are at 125 also or is there a regulator somewhere?

I have a '97 DP on the XC chassis.

[Gary RVRoamer]

The ride height valve controls the volume of air in the bags and therefore the pressure. It continually adjusts the amount of air in the bags to maintain the proper level (ride height).

[Vintage]

You're absolutely correct. I don't know what I was thinking.
I am having a problem with the system and this question just popped into my pea brain.

Someonw had detached the air line from the dump port on the left side air bag. I re attached it and the air system inflated normally then suddenly deflated and there was a continual escape of air from somewhere underneath. Since the coach was now lowered I could not get under to see where the air was coming from.
I just removed the newly attached hose as we were leaving for a trip the next day.

I think there is something amiss with the inversion valve.

[1ciderdog]

Not the same but an air suspension problem/question - the last couple of times I have started up the engine after overnighting air pressure comes up for the brakes to 120 or so but the air bags do not inflate. I shut it down the engine and restart it and the suspension airs up. Any thoughts on this one?

[KennethM]

Vintage, I had a ride height valve go bad and the ride height valve still worked but the check valve on the dump part of the valve failed resulting in a major air leak the compressor could just barely keep up with. I live about 6 miles from the Freightliner shop so really not a problem they got me in and fixed it by the next morning after overnighting the part.
Bob G, hopefully you are hitting the store button on the HWH system, if that does not work running the engine releasing the emergency brake and putting the trans in gear should work. You should not even have to move the coach but that failing you need to have someone look at the system unless you are up to the challenge.

[1ciderdog]

Kenneth - thanks for the suggestion. I had not thought about this but I did not use the jacks on these occasions, just let the air out. Driving the motorhome for a short distance did not add air to the suspension. Next trip I'll try the store button as you suggest. I do try to do everything myself unless the challenge requires special tools or special knowledge.

[Gary RVRoamer]

I've heard that some coaches do not close the dump valves until the jacks are raised. Maybe an artifact of the HWH jack system? Mine is Equalizer and the suspension starts to air up if I run the engine too long. And if I use the manual dump valve on the dash, it immediately begins to refill with air when I release the switch (it is momentary).

The motorhome manufacturer adds the leveling system, so this is not really a Freightliner question anyway.

[painter007]

A related question. my coach is low on the right front ,do the front bags get air from a separate valve than the back bags. do bags go bad with no leaks.or maybe the front right sping?the difference from top of the right tire to the inner shield is about 2 inches different than the left side.

[Gary RVRoamer]

The fronts do get air separate from the rears. There are ride height control valves that control the air. The typical arrangement is one valve for the front pair and two valves (left & right) for the rear, but a few coaches (like mine) do it the opposite.

Yes, air bags can leak, and so can the air lines feeding them.