[Bob]

Now, I am blushing again!!!

Hector

[Robert]

DKO,

As owners not all want to do mechanical work, but after 21 years of ownership I can state emphatically none of us needs to do our own work, but there is a huge benefit from developing an understanding of our coaches.

Nobody needs to memorize what Hector is teaching, but I do recommend that it is to be used as a valuable resource for the time when the suspension or air system needs work.

Over the years I have fielded many phone calls from owners who were stuck because of an issue with the suspension. The single most common problem (and it is a true problem) is that the bus will not come up to ride height. An owner with access to Hector’s presentation can clearly see the center solenoid in the valve stack in the steer compartment is the key to getting air through the ride height valves and in almost every case it was the solenoid coil that failed. Swapping it with any other coil gets the bus on the road in about 5 minutes. My point is as owners nobody has to be held hostage by a mechanic that has to learn the bus systems before making a repair. Even if the owner chooses not to make the minor repair he will be in an ideal position to assist a mechanic with either advice or a review of Hecotr’s tutorial.

One of the reasons Tom and I are seeking a broad base of owners and operators is so we can share information and knowledge to make Prevost ownership a positive experience.

[Archived]

Great presentation and I applaud your hard work ! Is it possible to get a hard copy of this in color format ?

[Ronald]

I will soon be adding an article that compliments Hector’s seminar which can be printed and which will help folks diagnose suspension system problems.

[Ed]

Hector:

Again I want to thank you. What a great teaching tool you have provided for the Prevost bus owners. Your presentation was factual, to the point and exactly the length of time to hold everyones attention.

The work you have done to simplify the understanding of the system is to be applauded.

Thanks again !!!!!

[Bob]

To supplement Hector’s excellent webinar a new article has been added here: http://prevostcommunity.com/articleDetail.asp?ID=55

This article will aid in understanding the Level Low suspension system and diagnosing problems that might occur. A lot of the problems encountered are relatively simple to address, at least enough to get you on the road. Copy the article and carry it in your coach in case you ever have a problem. It will help you identify and fix the problem and get you back on the road.

[Scott]

Hector, for starters let me say that you are the best technical writer there is. That presentation is a masterpiece. Thank you for explaining how it came about, too. Priceless.

And how therapeutic it was to listen to your Prevost Fort Worth experience! I have just escaped (not unscathed)

from a similar experience at WW Williams in Phoenix. I had been wondering if anyone else had ever had such things

happen to them. Thank you for being forthcoming about that as well. If I can ever get the stomach to, I will describe my experience in this forum, too, so that others can become that much better informed. I am tired of feeling like a lamb to the proverbial …. I do not enjoy being duped. None of us should have to be in that position.

So anyway, my coach has just developed the leans. This is the first time since I bought it 18 months ago. I am in a

town of 2,000 and staying here for the season. So your presentation is a real boon…a daggone life saver. I am going to use it and Jon’s PDF to diagnose the problem. Thank you, Jon, as well. I haven’t read the PDF yet but will next. (What’s with the spacing in this message? 🙂

I feel confident now that I can diagnose it and fix it. I am confident that I can do a better job than the majority of mechanics I have seen, who have left my coach worse off than when I took it to them. grrrrr

So thank you for relieving my anxiety. I had decided that many so-called experts were not but I was not sure how to go about fixing it myself. There is a vast difference in giving fix-it advice and giving a presentation that removes the clouds of confusion in anyone’s mind who hasn’t worked on these coaches for years. You are so generous with the rest of us. Thank you so much, Hector. I can appreciate all that you went through to bring us all up to speed.

Susan

[Larry & Diane]

Keep us posted on your progress Susan because we learn from others’ experiences. Hector’s presentation certainly clarifies how the suspension system works and it takes the mystery out of it when it comes to diagnosing problems.

What will help everyone is to recognize our suspensions are an evolving design by both Prevost and the converters. While the underlying principles remain over time there have been changes and additions so everyone needs to recognize the system logic on an early 90’s coach is going to vary from the system logic on a late 90’s coach.

A Royale may use the Prevost Level Low system, unchanged while a Liberty will include a proprietary automatic leveling feature that adds two valves. My point is that anyone should recognize Hector’s and my writings are generic, and when you post if you add a signature line with your coach type, model year, and converter we can better understand your specific system.

If anyone does have issues or need an understanding this is the place to air those concerns especially because Prevost is standing by to help.

[Archived]

Hi Jon,

I’m writing you in regular email because I don’t have a Reply button showing up in the Prevost Community

forum as it did the first time I posted. ?? Oh well. I’m new at these things and maybe it’s better if my first

posts don’t show up. 🙂

Sorry I didn’t put my coach in my signature. I have a

1996 Prevost Angola

470 Detroit Diesel

6-speed automatic Allison

The coach was manufactured in 1995, the conversion in 1996.

I bought this coach 18 months ago from Folmer and Vera Nyby of Michigan City, IN. We’ve been living in it

since then but have never experienced any leveling or leaning problems until coming here to Gold

Beach, OR. This is right on the coast. It’s a lot cooler here than it was in FL all winter (86 degrees most days) 🙂

and is even cooler than the San Francisco area, where I stopped for a few days on my way up here and never

noticed any leaning at all.

This is what it does is. I level it. That goes OK. Then about a day and a half afterward, it looks and feels like it’s leaning

to the right some, like the right rear is sinking. (The front was down pretty far already because the

coach is on a mixture of gravel and grass, so the site is uneven.) The coach continues to lose height on the right

side until I re-level it. Then the same thing happens again, at the same rate. I have re-leveled it 3 or 4 times, hoping

that something would stop sticking. No dice.

Here is what I have done so far to try to diagnose the problem:

1. I watched Hector’s presentation.

2. I read your PDF.

3. I found a multimeter volt tester and watched a YouTube demonstration on how to use one. I tested a couple of

AAA batteries successfully. 🙂

5. I went to the solenoids in the steer compartment and removed the one for the

right-side rear height. (4th down)

6. Then I got stumped because I couldn’t figure out how to check whether it is getting current or not. 🙂

7. So then I thought, “But if it weren’t getting current, it wouldn’t fill the bags so successfully when I am leveling, right?”

8. I concluded that I need to get the coach to a facility, where they can raise it and check for leaks at the points

indicated in Hector’s and your documentation, the ones that affect the right rear height.

The coach goes to ride height just fine, gets leveled just fine, and also lifts the tags off the ground just fine…or

what seems just fine to me…there is one thing about the tags though: when I pull the lever to lift the tags, the back of

the coach drops some and stays low until I release the tags again. Then it comes back up. The process of raising

the tags does seem to go very slowly, though. (I mean, it takes a while before the tags actually lift up off the ground.)

I sure will appreciate any help you can offer, Jon. Thanks so much. And sorry that I couldn’t figure out how to post my

experience…I’m shy but not *that* shy. 🙂

Susan

I cut and pasted Susan’s email to me because she seems to have trouble posting, which we will solve. My reply is below in the next post.

[Archived]

Susan,

You have the “leans”. From your description you leveling system is working perfectly except there is a leak associated with the RH rear. Based on the age of the coach, unless the air bags or associated Norgren valves have been replaced it is probable the problem lies within the three air bags on the RH rear, with the 3 port Norgren between the drive and tag axle or the 5 port Norgren controlling the RH rear.

It could also be any of the connections or fittings. If your coach aux air drops below 30 or 35 pounds that also can cause the rear to drop, but typically the drop does not take place over a long time frame but occurs suddenly. You would hear air escape and the whole rear would drop. That system logic was changed and yours may not have that logic.

Having said that, unless you know for sure that the air bags or Norgren valves have been replaced from the originals you might consider eliminating the diagnosis to isolate the problem and just replace them all to put the issue and future potential similar problems behind you. The replacement of air bags and valves on your coach is not a complicated thing but it helps if whoever does it can pull at least the steer wheels and the outer drive axle wheels for access to some of the air bags, and has access below the coach for ease of replacement for the others. Replacing the valves requires access from below.

What is happening with your coach right now is age related and it has not reached the point where you absolutely must react to the problem. It is a pain, but not much more. Yet. If it were my coach I would time the needed service to when I was near a service center or a shop that knows Prevost coaches.

As to the tag, when you pick up the tag you are taking the 5 ton (or more) that the tag axle supports and adding it to the weight the drive axle air bags are trying to support so it is expected the rear will drop. Some tag axles will either not lift or will not lift quickly but will over time. All of that is dependent upon the condition of the lifting chambers and if the lifting arm pivot point is maintained and moving freely.

[Kevin]

Thank you, Jon. The Reply buttons are back. (I was logged in last time…I could swear… 🙂

Many thanks for your good advice about replacing all the parts that could go wrong due to age. Very wise.

Meantime, until I get to a service center, would it be bad for the engine if I turn it on every 3 days or so to re-level, for only about 10 minutes at a time? I am settled in a rather remote, tiny town for six months….

There she is (below). She’s been babied all her life. Garaged. Maintained. Loved.

Susan

1996 Prevost Angola

470 Detroit Diesel Series 60

Six-speed Allison

[Archived]

Susan,

You are certainly in good hands with Jon’s comments. And thanks so much for your comments on the presentation. As I said in the demostration, the presentation was born from a pure need to understand how the suspension system worked so I could repair it. I have found 90% of my leaks with a soapy solution in a squirt bottle. The test equipment that I made is for the other 10%.

Good Luck on solving your problem, remember, never crawl under a Prevost bus unless it is properly supported. If the coach were to drop while you were under it, well ………

Thanks again and good luck,

Hector

[Archived]

Susan,

I doubt if anyone will tell you starting and running the engine for 10 minutes every couple of days is a good thing, but assuming you are going to service this issue within a reasonable point of time I doubt if is going to do much if any measurable harm. Your engine will create a lot of moisture doing this and eventually you can do some harm, but not every campsite is sloped requiring frequent engine starts and stops. When you start your engine to drive the coach the moisture you create before it warms up is “boiled” off.

I assume you have an auxiliary compressor. If you do, and if the aux system pressure can be maintained at a sufficient level to raise the rear you might consider using the aux compressor. I would be confident if you can get 100 PSI out of the compressor you can raise the rear on your coach. The key will have to be “on” so you can operate the level low system. Just guessing, you may find 70 to 80 PSI is all you need to raise the rear.

[Susan]

Thanks, Hector. And not to worry. My imagination has done a lot with Jon’s warnings about not getting under a coach that hasn’t been properly lifted. And I’ve also fantacized more than once about having my own pit. They ought to start including them in the pull-through sites.

Many thanks again. Gotta say again what a work of beauty that presentation is, with lovely interactive graphics. Oh, speaking of which…you mentioned that you were going to share some files with those attending the webinar. Could people like me download any of those files, by any chance?

Susan

[Archived]

I’ll be doggoned. Sure enough. I turned the batteries on and flipped the Air Comp button (on the dash) and to my surprise (and elation), the coach leveled itself. The compressor in the steer compartment made lots of noise all the while. Which it does from time to time. So I turn off the Air Comp button when I’m in a park so that the noise doesn’t bother them. If I keep it on, will the Little Generator That Could keep leveling the coach? Or do I need to have the batteries on and the key turned?

Omigosh, what a relief.

Thank you so much, Jon. Susan