[Rodger]

Richard,posting a pic is not hard, there are several postings on this site telling you how.I just learned,so I am sure you will also. Next,need information on you Signature as to year of your bus and which Conversion.That done,you will get Many,Many replies and the information will lead you to a cure. Hard to say, the specialists here will come after you real quick, but they need some background

[AL]

Richard,

Your vintage coach is likely very different than almost all the conversions on this site. While that might make accurate specific advice in short supply there are likely some generalizations that can be made.

Your leveling system control should have a position for driving and when the coach is set in that position your coach should maintain a height above the road via three ride height leveling valves, one on the front axle and one for the left and right sides on the rear axle(s). It is probable you have some type of valving that determines if air is directed toward the ride height valves, or other valves used to level the coach manually such as in a campsite.

I suspect your leveling system design preceded the design employed using Norgren spool valves. I think your best hope for a soultion is to contact Prevost engineering and see if they can shed some light on your suspension system.

If you do your own maintenance and repairs and want to tackle this yourself the starting point might be to remove the suspension valves and verify they are functioning as intended and are leak free. If the air system has been neglected and moisture has gotten into it, damaging valves in the process, normal analysis of the problem is almost impossible because nothing will act as intended.

DO NOT GET UNDER YOUR COACH UNLESS IT IS SUPPORTED AT THE BODY SUPPORT POINTS. I stress this because any work on the suspension is likely to cause the coach to drop instantly.

[Richard]

Thank you for your replies, I will persue the suggested steps to try to find out what system I have and post a picture. I believe the leveling system on the panel is an earlier set up to the rotating switch I have seen here and was installed by Liberty. The first thing I need to do is understand how it works, I was hoping to find someone that possibly had one back in the day here. Although it is an older coach, it has had some updates and is a really nice one. I am just needing to correct the bleed off of air situation and I will be off to a great start.

Thank you for the safety regarding the air suspension, I am very cautious of getting under the coach without support, I have read alot about that here as well and will make sure it is safe before crawling under it.

Richard

[Archived]

Richard, my focus would be on the valves, although I am sure you have leaks. If you set your switches to the driving or road position the coach should automatically go to the ride height and control of that is in the ride height valves that are likely getting air via other valves. If you check the supply side of the ride height valve in the front and follow that back it is likely you are going to find the valve that should have shifted to supply air to the ride height valve is not functioning. That is a guess on my part, but that is how I would begin.

The fact you can raise the front tells me if you have leaks they are not so big as to inhibit the function of the air bags. I am suggesting you have a two step process, the first of which is to get the ride height valve with an air supply or get it working if that is the failure point. But since the front end drops after a while then it means you also have a leak and it could be in an air bag, a fitting or a valve. That is the secondary problem for now, but it must also be addressed.

Unless Prevost made a substantial change it is possible your valves that control air supply to the ride height valve are located in the steer compartment. I still suggest a call to Prevost engineering or tech support because they can save you a lot of time.

[Hector]

Wouldn’t hurt to share–might be someone rite next door to help. I live in SW Indiana. You should be able to go back to standard coach leveling system while driving bus=leveling valves controled by height control valves(air valves with rods connected to suspension) that detects need to raise or lower coach height. Will be one front and two rear. Around $50 each. At this point we have no idea what previous owner or liberty did to suspension. Pictures tell much more than words. You should not have to manualy add air going down road.! Bob

[AL]

I have minimum experience with this model coach, however, I will offer a few comments. The link below will provide a drawing that should offer some help. On the drawing, note item# 2, 3, and 4. These represent the pneumatic push buttons you mention in your first post. Study the drawing and you will see that an electrical solenoid provides the necessary alignment of air signals for the road height leveling valve. With your comments of needing to add air using the manual push valves, my best guess, is either the electrical solenoid that aligns the ride height signal or the ride height leveling valve is faulty. You should not overlook the possibility that an electrical issue could exist.

http://prevostparts.volvo.com/technicalpublications/pdf/d140115_f.pdf

If interested, send me a private message with your contact telephone number and a good time to call. I will contact you to chat.

Good Luck,

Hector

[Lee]

attached is a pic of the air leveling system. Does anyone have information of how this type works?

Thanks

Richard

[gary]

Thank you Hector,

Although I am presently assigned in KY right now, I am being relocated to Houston, TX in December.

I will be about an 1 1/2 hours from your listed location. May I come talk to you when it is convenient?

Richard

[Gerald]

Richard,

The system that you have is really a simple one to use. I had the same one on mine. When you flip the toggle switch on the panel you disengage the bus leveling system. The red light on the panel and a light on your dash should be on when the level low in on. When you flip the toggle and turn the level low off your bus leveling is back on when the key is on.

To check to see if this is your setup, turn the key to the on position (do not start) and flip the level low toggle and see if the lights come on. Next while its on, push the three leveling valves and lower the bus to the ground. Next, start the bus, run until the air tanks are full and flip the toggle to turn off the level low, the bus should raise to road height.

[Hector]

might be burned out? good luck also ck rod on leveling valve that seems to be mal functioning —be safe….stay alive! Bob

[Archived]

Richard,

PM me when you are in town.

Hector

[Archived]

Thank you for your replies, it is greatly appreciated. I will be away from the coach for a couple of days, but I will trry the switch question. I have flipped the switch before and the light came on, but nothing changed, although I can’t remember whether I had the air system full or not so I will retry and update.

The brake air is still full, but the other air system is empty, but I haven’t found where the air is leaking from yet. Even though I have a small leak that charges properly when the coach is running, if my road position air was operating properly, wouldn’t my coach maintain proper position? As I try to grasp the possible faulty components, for the time being, if my theory is right about the available air, I would like to find the actual issue further down the line unless you tell me that I need to fix the air leak first. I will in fact fix the air leak, but I wonder why the coach loses front position with fully charged air and manually have to ad air to level it again?

Where is the leveling arm located on the front axle?

Thanks again for all the valuable inputs from everyone…..

Richard

[Georges]

Richard,

This is how I would approch you coach based on your comments.

I would place the coach on a level concrete surface inside a quite building. Hook an air compressor into the system so it feeds the wet tank. adjust the air pressure to #120. Use the level low valves to raise the front about 1 inch above ride height and then support the chassis right behind the steers on the main frame, (my 2 supports are 13 inches). Then raise the rear of the coach 1 inch above ride height and support the rear of the coach right behind the tag on the frame, (14 or 15 inchs). Then you can let your bus down on these supports. Now you can start to go under your bus and start looking at all the leveling valves and stuff.

As statedon this site, do not go under the bus without proper supporting.

Once you get this far, you can go under the bus and start moving the leveling arms and get close with how your bus works.

[Tom]

Richard,

If your vintage is similar to later models with a solid axle your ride height valve should be located in the center top of the front axle area. It will have an arm that extends outward and that is free to pivot as the coach goes up and down with respect to the axle. Extending downward from the arm is a rod that can be adjusted in length and that is attached to the axle. The valve will have a single air line to it, and a short 6″ piece of tubing for exhaust air.

It might be made by Haldex and is likely to be a time delay response. This is important to know because when you begin playing with it, you may not immediately see any action when you move the arm up or down. There might be a delay of a few seconds. That is normal. Later coaches have instant response action.

I’ll repeat the warning………never ever get under your coach, especially when working on the suspension unless the coach chassis is supported at the chassis support points.