[Jacky]

I think if you are using the HWH to level the coach and you drop the front end with the Prevost level low knob and then return the knob back to the drive position, the HWH is going to try to re-level the coach on its own.

[Archived]

Mikee, I cannot answer your question, but I would advise you to completely learn how your converter set up you coach suspension system. A failure to do that could result in unplanned problems.

From time to time we all have to raise or lower the coach or a corner of the coach or the front or rear of the coach. There are a multitude of reasons why the normal driving height just is not going to work. For example if you have to cross a high crowned set of railroad tracks you risk high centering the coach. The solution is to approach the crown at a steep angle, but usually that is impossible so the alternative is to raise the entire coach to keep the belly from dragging, or worse to prevent getting hung up.

If you need height clearance the easiest way to prevent damage to a satellite dish or A/C unit is to lower the coach. If you are pulling out of or into a driveway with a steep transition from the road surface to the driveway slope you may need to raise the front or rear to prevent dragging.

Every example is common and in every case if you set the coach at the correct height setting to avoid trouble the last thing you want is to have the suspension take on a life of its own and go up or down because part of the system is trying to do something you do not want it to do.

Owners of a system like yours should post how they address this issue because if you haven’t encountered clearance issues that can be dealt with by changing suspension height, you will.

[AL]

Jon,

I know how the suspension is set up on the coach.

My question was and is the unit is in level low, HWH out of the picture, lower the front end and it raises back up on its own. That, to me, has to be one of the 3 way valves in the front suspension being stuck in the ride height mode. The H3 is set up differently that the XLII. To me, it appears the 3 way valve(s) are not shuttling to level low mode. According to Prevost there are 2 3 ways in the front of an H3. I cannot see how it could be anything else.

So, instead of telling me to learn how something works, offer your thoughts based on the info provided.

Thanks

[Archived]

I’ll stick with the first sentence of my previous response. Until it is understood how the converter set up the suspenson modification it is difficult to diagnose what is going on. I think you said two different things regarding the HWH and it is not clear to me what you meant.

I the HWH is removed from the picture by disabling it and the coach is in the manual mode, with the front lowered it is not going to rise unless you either push the “up” button to open the path to the air supply valve into the front air bags, or the path is already open because the valve controlling air flow to or from the front air bags is stuck in one position.

If the air supply valve is indeed stuck open you can prove that by turning the selector to one of the rear positions and then it should rise of its own accord., meaning either the rocker switch is supplying power to the valve or the valve itself is stuck.

When I am diagnosing I make sure any added systems installed by the converter are turned off, disabled or out of the picture. Then I verify electrically the solenoid coil on the manifold stack is getting power. Once assured of that I open the line from the solenoid valve to make sure it is flowing air when it should. Then I go to the respective valves, whether 3 port or 5 port to verfify the pilot signal air is at the actuator. If the 3 or 5 port does not respond to the air pressure or removal of air pressure then the source of the problem is identified.

I can say a poorly maintained suspension system filled with water or that has been filled with water will do things that make no sense because the Norgrens can get stuck or develop hydraulic lock so the only way to verify the location of the problem is to go step by step.

Explain what is different between the H3 and XL level low suspensions. That’s a new one on me.

[Archived]

Jon IMOHO class act

[Archived]

Taking the HWH out of the equasion, with the key on and level low in the drive position, the only valve/coil in the 5 port stack that will have power is the center one. Turning the level low to front should remove the power to the center valve/coil and nothing should happen until you push either the up or down button. Pushing the down button should drop the air from the bags via the front two 3 ports. Once the bagas are deflated they should stay that way until either the up button is pushed or the selector is turned to drive. You know all this, I’m just working through it.

It almost sounds like the level low selector is keeping the center valve/coil (the drive position) energized. Buddy has a good point as well, may be a conflict going on with the HWH and level low.

My H and my previous XLII is no different when comparing the level low other than converter modified items.

[Archived]

The difference between the XLII and the H3 is on the XL the 3 way is before the ride height valve and on the H3 it is after.

It is not the manifold in the run bay.

It is not water in the system, etc, etc. It is not the result of bad wiring.

What is happening is then the level low rotary switch is turned to front and you lower the front when you release the down rocker the front end will raise back up. Lower it again and it will raise itself again, etc. According to the schematic it appears to be one of the front 3 way valves. It is not shuttling when the level low is set to front, so the ride height valve stays active and the coach raises to ride height.

[Archived]

Have you checked it electrically to insure the rocker switch is not keeping power to the solenoid valve in the manifold which will keep air to the air supply.

Have you switched to one of the rear positions to see if either of them acts the same way as the front.

That is why I start with the basics. I can tell a whole lot without getting under the coach by verifying the various switch positions are sending or interrupting power to the solenoid valve coils on the manifold as intended, and also by verifying the solenoid valves on the manifold are opening and closing as expected based on the electrical signals.

The wiring does not have to be wrong for there to be a failure. All it takes is for the rotary switch, the momentary contact rocker switch or even something in the HWH control to not function as intended for the coach to act wrong. The rotary switch for example is a complex set of contacts and things do fail.

You may not have moisture in the system now, but it may have had in the past and from experience I can say that the aluminum in the spool valve corrodes quickly and the white corrosion becomes a white or gray sludge that impacts how valves work. But before climbing beneath the coach and replacing what may possibly be a bad or slow valve it is good to “pick the low hanging fruit” by doing a very quick check to insure the electrical signals are correct and they in turn are creating the correct pneumatic pilot signals.

[Larry]

Jon,

I have already done all the basic troubleshooting. I have narrowed it down to one or both of the 3 way valves for the front end.

I have ordered them from Prevo and should have them next week. I will update aftrer installation.

The 3 way valves are priced at 80 bucks apiece.

[Andy]

I will admit that I just cannot get my brain wrapped around the problem.

When you press the rocker switch you open the path between the air bag and exhaust. That makes the front end go down. When you take your finger off the rocker switch the only thing that should change is the 3 port that exhausts the air closes. Yet it sounds like you are then dealing with an open air supply valve that resupplies air to the air bag.

What I cannot understand is if the air supply valve is open, allowing air under pressure to pass into the air bag, one of two things need to happen. Either the air supply valve is open all the time, something that would show up as you exhaust air to lower the front as a pressure reduction on the aux gauge, or when you release the rocker switch, something is sending a signal to the air supply valve to open. I cannot think of anything else, so I am anxious for your diagnosis.

[Tim]

More thinking, not usually a good thing.

On possible reason is the HWH is not disabled and is commanding the coach to level itself. Easily checked. Point the nose of the coach uphill. If the front is lowered putting the coach in a near level position it will not come up.

I’m going to stick my neck out a country mile here and guess it has nothing to do with the 3 way valves.

[Archived]

I think we are about to find out what happens when an unstoppable force meets an immovable object.

[TERRY]

You are about to find out how difficult it is to do a diagnosis of anything via a forum or email.

It is incredible how much your senses come into play when trying to solve problems, and how many little things you can do and check in minutes that neither of us might be thinking about or saying right now.

And most of all we are not only trying to diagnose a problem, we have the ultimate problem of communications in which what one of us says is not necessarily what the other hears.

[Olympia Luxury Coaches]

Mikee

Humor me please and tell me how the HWH is tied into the air system.

I only have level low but in my mind I can’t figure out how HWH would be attached to your air system without getting into the LL.

Later

bv

[Archived]

Bernie, I cannot be specific about HWH, but as you know Liberty also has a self leveling feature and it piggy backs on the Prevost system.

Liberty has modified it to the extent it has additional Norgren valves. The operating principle is there is a master switch that has three positions. One position enables the automatic feature which uses a pendulum to identify level and its operating logic commands the solenoid coils in the 5 solenoid valve manifold to open or close the solenoid valves as necessary to level the coach. I am sure HWH also has some means of sensing level and its system also uses the solenoid valves in the manifold to level the coach.

The other position on the Liberty set up is a manual position. When selected you can raise or lower each of the three positions, front LH rear, RH rear manually by selecting what you want to do on a switch for each position. The road or driving position is the third part of the three part “master” switch and that brings into play the Prevost system that functions through the ride height valves.

I do not know the particulars of the HWH but regardless it is like the Liberty system in that it sends the electrical commands to the solenoid valve stack. I don’t know if it adds any Norgren control valves,

I believe the only advantage to either system is the added automatic leveling feature.