More on ride height???

Topic: More on ride height??? (Read 2194 times) previous topic - next topic

More on ride height???

January 27, 2018, 10:30:34 am

Does anyone know of a previous discussion here on the forum on "How to set/adjust the ride height?" I've searched, but have had no success, and it seems like I've seen it here in the past.

I was dumping air from the front valve when I went into travel mode and the coach would rest on the front tires. I replaced the front ride height valve, but I'm not sure how to do the adjustment. So when started up to test everything out, it still seems to dump out all the air when I enter the travel mode.

So I'm wondering if:
1) I simply need to adjust the ride height valve?

Or if perhaps
2) Travel solenoid is bad?
3) or the HWH computer has gone kaput?

I have looked at Barry's page, and that gives me a much better understanding of the system, but I still haven't located anything on the actual adjustment procedures.

As always, thanks in advance.

Russell

Re: More on ride height???

Reply #1 – January 27, 2018, 11:11:31 am

Good morning Russell,

I'll try to add a couple links below to other references. The ride height valve should have a horizontal rod inserted in the holes in the valve. When the rod is perfectly horizontal, the valve is in the "neutral" position where air is not being vented. From that position, any movement of the rod, either up or down, should cause the valve to either add or subtract air from the associated air bags.

The horizontal rod in the valve is attached to a vertical rod, which is attached to the suspension frame. Suspension movement (up and down) moves the vertical rod, which moves the horizontal rod, which activates the valve. The relative position of the linkage rods is changed by loosening the little band clamps and sliding the rods in the rubber sleeves.

It's a trial and error process. Make a small adjustment in the rods, then see what the coach does.

http://www.meritorwabco.com/MeritorWABCO_document/tp96139.pdf

Height Control Valves.

Ride Height Adjustment

Haldex Height Control Valve (HCV) Troubleshooting Guide

Re: More on ride height???

Reply #2 – January 27, 2018, 11:57:12 am

Thanks for the links. I had seen the first link and it helped give me some understanding of the system.

But the second and third link that you sent, I had not found. I've read them briefly, and will have to digest them, but they should help quite a bit.

Again, Thanks,

Re: More on ride height???

Reply #3 – January 27, 2018, 12:08:01 pm

I think Don's comments on adjusting ride height cut to the main problem - how to get under the coach (safely) while making the adjustments. Of course, if you have a PIT (like some lucky souls) it is a piece of cake. Otherwise, pain in the rear.

Don said something about making "safety blocks" that would support the coach (with air bags deflated) at the correct ride height. Then you could crawl under, and adjust the rods to where the control valve is in the neutral position. Then air up the coach, remove the blocks, and check the height. I think that would get you real close.

Question: What was your source for the metal height control valve?

Re: More on ride height???

Reply #4 – January 27, 2018, 02:30:14 pm

My quick and dirty method to get the ride height adjustment done is as follows;
Edited for clarity (I hope!)
The following is after I had installed new ride height valves, aired up the coach and had already raised the coach and blocked the frame with 12" frame blocks. The ride height valves were already set to neutral position (neither adding or dumping air from the bag). That is the position that the horizontal rod needs to be in when ride height is correct. You have to make sure of the orientation of the valve (they rotate freely 360º) otherwise the valve can add air when it should be dumping or dump when it should be adding. There are marks (hard to see!) cast into the housing to help with this. I did this procedure on a very level flat concrete floor.

First I made two frame blocks out of some 8" long X 1 ¼" pipe nipples, a matching floor flange and a cap that I sawed the top off of to make total height of 8 9/16" (or really close to that). Next, I placed these blocks close to the bags (rear most in the rear and front most in the front). These stands gave me the confidence to be underneath and gave me a firm indication of the spacing between the air bag supporting members. Then I dropped the coach using the HWH control pad to approximate ride height, but just above the supports I made. I then installed the horizontal linkage while already attached to the vertical rods with clamps loose enough to easily move the rubber connecting boots along the vertical and horizontal rods. I tried to keep the ride height valve I was working on in the neutral position while doing this, but the important thing is just not to add too much or lose too much air in the process. You can easily tell when it is dumping or adding air by the sound. The valve is easy to rotate by hand and doing so gives you a sense of how wide the neutral position of the valve is. So as I was doing the adjustment, I would let the coach settle until it touched the stop of my shorty frame block, then rotate the valve the other way until I could see the the weight come off of it. This is where I set the horizontal rod at the 90º position with the vertical rod very close to the vertical. When I could tell that the valve was as close to the middle of its dead zone (zone of not action) as I could make it, I tightened the clamps and checked the links for movement. On the back, it is possible to do the adjustment without being underneath, though in my case, it entailed making an access hatch on the street side compartment I put in.

On the front, it is trickier because you actually have to be underneath while doing the adjustment. That is where I really appreciated knowing that the the lower limit of the coach above would at least be above crushing height if I screwed up or had a sudden loss of pressure. It required several trips between the both sides of the back and then up to the front to get it to where I thought it should be. To test, I dumped all the air (with the engine running and my ride height adjusting frame blocks removed of course!) and let it come back to ride height and check all four corners and then repeated the process by raising the coach to the max and letting it settle back into ride height. The ride height ended up being consistent after doing this, so I called it good.

The trickiest part is definitely setting the front since there is only one ride height control valve up there so you have to split the difference to get an average that gets all corners as close as possible to the correct height. Hopefully, this might help someone trying to do this, but safety first! While I often feel that I would like to be buried in my coach, I have no wish to be buried underneath it! So if you decide to try what I describe above, make sure that you do your own research and understand what is involved. Besides, this was already three months ago so I may have left out a step or glossed over something that could be important to your outcome, so caveat emptor!
Don
Don

Re: More on ride height???

Reply #5 – January 28, 2018, 08:13:30 am

Thanks Don... Appreciate you taking the time to write that up for me.

It's been raining like cats and dogs here in Baton Rouge, and I'm going to have to wait until it dries up before I get the coach out of the garage to poke around some more.

I can say for certainty, that you're not the only one UNCOMFORTABLE working under there while tinkering around with the air lines.

Re: More on ride height???

Reply #6 – January 28, 2018, 08:42:58 am

Russell....As Chuck mentioned above could you share where you bought the "metal" HCV (in the Pic) ?

Thx

Hans

Re: More on ride height???

Reply #7 – January 28, 2018, 09:01:53 am

Thanks Hans for the reminder. I'm getting forgetful these days. I intended to mention in the earlier post, but... well, you know.

I ordered the ride hight valve directly from Foretravel. I knew it would cost more, but I also knew they would get it right out to me and it would be an exact replacement. I think their price was $241... or somewhere in that ballpark.

Re: More on ride height???

Reply #8 – January 28, 2018, 10:20:37 pm

Quote from: Russell – January 28, 2018, 09:01:53 am

Thanks Hans for the reminder. I'm getting forgetful these days. I intended to mention in the earlier post, but... well, you know.

I ordered the ride hight valve directly from Foretravel. I knew it would cost more, but I also knew they would get it right out to me and it would be an exact replacement. I think their price was $241... or somewhere in that ballpark.

I don;t think you can always depend on the ride-height valve from Fortravel being a direct replacement for the one on the coach.

This is what Foretravel sold me as a replacement when I was being proactive.
"Leveling valve by MERITOR (S464-002-443-0)"
Meritor WABCO S4640024430 Chassis Height Control Valve: AnythingTruck.com,...
It looks like the metal one in the picture and works the same way.

When it came time to replace my broken one I decided for a couple of reasons to get a plug compatable from Haldex.
This is what I replaced on the coach
90555105 by HALDEX - Type EGP - An Immediate Response Height Control Valve

The main reason was that the placement of the holes in the bracket suspending the valve didn't match those of the valve itself.
I didn't want to try to manufacture a new bracket.

Obviously Foretravel used at least two different valves over the years.

A suggestion, get new elbows.

Re: More on ride height???

Reply #9 – January 29, 2018, 11:26:23 am

Understood... but in this case, the valve FT sent me was the exact same one that I removed. Thanks for that heads-up however.

I have one further question before I head out and crawl around under the coach again. Ours is a '99 U320 and I've never specifically had to search for the HWH Control Box. Can anybody advise where it might be located? This is the control box where the fuses are located.

I think I'm going to explore the emergency travel procedures outlined on Barry's website and remove the 7.5 amp travel fuse.

Re: More on ride height???

Reply #10 – January 29, 2018, 11:53:48 am

Mine is in the second bay back on the curb side attached to the top of the bay in an aluminum box.

Re: More on ride height???

Reply #11 – January 29, 2018, 12:57:43 pm

Ours is on the curb side in the front of the storage bay in our 36' 99' U270.
Don

Quote from: Russell – January 29, 2018, 11:26:23 am

Understood... but in this case, the valve FT sent me was the exact same one that I removed. Thanks for that heads-up however.

I have one further question before I head out and crawl around under the coach again. Ours is a '99 U320 and I've never specifically had to search for the HWH Control Box. Can anybody advise where it might be located? This is the control box where the fuses are located.

I think I'm going to explore the emergency travel procedures outlined on Barry's website and remove the 7.5 amp travel fuse.

Re: More on ride height???

Reply #12 – January 29, 2018, 05:26:43 pm

Thanks for the further assistance. I was able to easily locate the HWH control box with your guidance. We have an older Foretravel entertainment center (TV and radio) in curbside second bay and so I had to access the HWH box via the driver side. Also, the cover to my box does NOT have any identifying HWH stickers, so this forum saved me A LOT of searching. THANKS EVERYBODY.

By way of offering something back to the forum, I took some photos while running through the procedures and locating the fuse. I will start another thread and post those pics for further reference. I know it might only be useful for folks with coaches of my vintage, but hopefully it'll be able to assist others who are not as mechanically talented as you guys are.

Thanks again for the guidance.

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More on ride height???

January 27, 2018, 10:30:34 am

Re: More on ride height???

Reply #1 – January 27, 2018, 11:11:31 am

Re: More on ride height???

Reply #2 – January 27, 2018, 11:57:12 am

Re: More on ride height???

Reply #3 – January 27, 2018, 12:08:01 pm

Re: More on ride height???

Reply #4 – January 27, 2018, 02:30:14 pm

Re: More on ride height???

Reply #5 – January 28, 2018, 08:13:30 am

Re: More on ride height???

Reply #6 – January 28, 2018, 08:42:58 am

Re: More on ride height???

Reply #7 – January 28, 2018, 09:01:53 am

Re: More on ride height???

Reply #8 – January 28, 2018, 10:20:37 pm

Re: More on ride height???

Reply #9 – January 29, 2018, 11:26:23 am

Re: More on ride height???

Reply #10 – January 29, 2018, 11:53:48 am

Re: More on ride height???

Reply #11 – January 29, 2018, 12:57:43 pm

Re: More on ride height???

Reply #12 – January 29, 2018, 05:26:43 pm

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