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View Full Version : Now I've got a REAL problem!



michaeldterry
04-11-2010, 10:54 PM
Some of you may recal that Tom (truk4u) posted that he drove by Evangeline's storage location a few days ago and noticed her "butt" sagging. It's true that she would lose some air after sitting for a few days, but would always come right up to ride height and stay there when I exercised her. I knew that it was a matter of time before i had a problem that had to be addressed. Well - it appears that today was the day! Vita and I went to the bus to run her a bit and actually take her to visit the new (downsized) house we are closing on in a couple of weeks to make sure that we would have no issues with ingress/egress or parking in front of the new house for loading/provisioning for trips. When we got to the lot, I did notice that she was sitting low, but it had been a few days since she had been cranked and run. She cranked right up - no problem. But we noticed as she was warming up that she was not coming up to ride height. I manually raised her a bit via the HWH control panel and moved slowly off the lot hoping that I had a sticky valve that would begin behaving once I got rolling. I knew she was "building air" because my dash gauges showed 105 lbs+ and she was "popping off" every so often as the air pressure reached the top of the set limit. However, the rear end did not raise and the ride (albeit very slow) was unaturally "bouncy". I pulled off the street and did a walk around visual examination. The rear rubber fenders were all but sitting on the tires!. Once again, I manually raised the bus via the HWH control panel to about 14" front & rear. We eased out on the road again and the bus felt much better! It was only a couple of miles to the new house, so we headed there. The good news is, although the entrance to the subdivision was tight, we made it with no sweat and even found that the cul de sac at the end of our street posed no problems for getting the bus turned around to head back out. So we stopped in front of the new house and took a few minutes to go inside to take some measurements we needed for planning.

We were in the house for an hour or less and when we came back out, the fenders where sitting on the tires again! The front seemed to have held up, but the rear was totally down! I started the bus and ran it on high idle for several minutes to let air rebuild. Again - the bus seemed to be "making" air (by the gauge readings and the ocassional "pop-offs"), but the bus would not rise to ride height! I had to at least get the bus back to the storage lot (approximately 5 miles), so I once again manually raised the bus via the HWH controls to a height of about 14 inches and left for the lot. The entrance curbing to the lot can be a little rough, so I stopped across the street from the entrance and raised the bus again to insure i didn't scrape. By the time I got the bus maneuvered into her spot and hooked up, she was sitting on the fenders again!

I know I'm going to need a Prevost certified shop/technician to remedy this problem. I just don't know where I should take her (or how to safely get her there without doing more damage). I need guidance/help/advice, etc:


Is there anyone/anyplace in the Atlanta/North Georgia area who you guys would trust with diagnosing and making the needed repairs on a problem like this?
If there is nobody qualified in North Georgia, where would you suggest taking her? Prevost Nashville? CoachWorX in Clearwater, FL? Millenneum in Sanford, FL? Russell Coach in Knoxville, TN?
Whoever I end up choosing, I'm probably going to try to "bite the bullet" and get several niggling issues resolved at once besides the "biggy" - (nonoperational entry keypad, nonoperational door air lock, some small lighting issues, etc) - so I need someone who has a diverse skillset and experience
Would I be better off having someone come to me instead of trying to "limp" the bus several hundred miles? If that's the case - how do I find someone? Can you guys recommend someone you trust who understands that disabled handicripples don't have a pile of cash laying around to give carte blanche on repairs/upgrades?
I realize that this post is totally exposing my underbelly, but i've got to ask for help and I can think of no one that I would trust more than my POG brethren to steer me right!

I'm hoping for help of any type you can offer and will very much appreciate your generosity and kindness!

garyde
04-12-2010, 12:27 AM
hi Michael. Not a big problem. A bad solonoid or Norgren valve. Any bus shop shoulld be ablle to locate and repair. If you have not read the norgren valve article, it will give you info on how the system works. Also, read the current posts on 'Front wont go up' under on the level.

Jon Wehrenberg
04-12-2010, 07:23 AM
Michael. First, don't drive the bus if the rear will not stay at the driving position. You can damage it.

Diagnosing a malfunction on the suspension system is not difficult, but it requires a systematic step by step analysis. Superficially I think it would be easy to say that the solenoid valves or the Norgrens are at fault, but the fact that your description says the rear (suggesting both sides of the rear) drops I can say you have at least two problems.

We can keep this discussion here on the forum, or go to emails, but I would urge for general interest we do it on this forum, with you at the bus manning the tools. That will help everyone because maintaining the driving position is critical, leveling in a campground is less critical so I think everyone needs to understand how to get their bus at the driving height via temporary repairs.

Off the top of my head I would say you have a leak in both sides of the rear. That is not your major concern right now but it is something you do need to fix. I suspect your front stays where it needs to be although you do not mention it. so it leads me to guess your middle solenoid valve is not funtioning. Replace it with any of the others, (just swap the coil first, and if that doesn't do it, swap the valve itself) , put the control in the driving position and see if that (temporarily) cures the problem.

If not, lets pick a time when you can be at the bus and I can be at the computer and we can walk through the diagnosis.

You will not have to get under the bus. If it comes down to a suspected bad Norgren valve(s) then the problem is more complex than I am thinking right now.

truk4u
04-12-2010, 08:52 AM
Michael,

Bleakley in Douglasville was a Prevost Dealer and they used to have a seperate shop for bus sales and service. You may want to give them a call.

michaeldterry
04-12-2010, 02:46 PM
Gary, Jon, and Tom - thank you for your prompt responses! I'm cautiously encouraged to know that the issue may not be as major (from a resolution perspective) as I had feared! Jon, getting to the bus with a computer and online access should not be a problem as I recently got Sprint's "Overdrive" mobile hotspot device and activated the service as we've found that the WiFi in the various RV parks is spotty at best - nonexistent at worst! Since Vita's work requires that she have constant dependable online access - I went ahead and signed up since we are already Sprint cell customers.

I would like to get a little more information so that I can be as prepared as possible when we "go to work" on the issue. I agree with the benefit of keeping the details of the project here on the forum in hopes that it may benefit someone else at some point. However, I need to make sure that we know what we're looking for and where before we go poking around. Vita will be the one primarily handling the tools as my lack of dexterity/mobility makes working with hand tools a very frustrating/tedious exercise for all concerned (I can "supervise with the best, though! - and in all fairness - I can do some stuff with my one functioning hand if it doesn't require particularly fine motor skills) :p

It would be a wonderful help if you and Vita could trade e-mails with her questions or even talk to you on the phone (Yes - Vita usually acts as the "spokesmodel" for us because my voice is weak and hard for others to understand most of the time - the aftermath of permanent damage to my trach and vocal chords from having a tracheostomy for 6 weeks after my accident).

I just went out to the bus to "poke around" a bit. I was able to open the outside compartment beneath the driver's seat where I remembered seeing it said the Norgren valves live. I saw a large 5-way contraption that had a Norgren label on it and also saw a vertical "stack" of 5 things that look like relays to me. Each one had a small red "post" sticking out of it with a slot on top (like a small flat blade screwdriver would fit). Am I in the right area? The right ballpark? The right country??? :rolleyes:

I cranked the bus and ran it on high idle for a fair amount of time to see if the problem had spontaneously repaired itself - no luck! However, the bus was able to be raised manually with the HWH controls (I didn't move her, though). I did a few other housekeeping items while there and then shut her down to come home and report to the POG experts and beg for guidance for "next steps"! :o

We have a long planned family trip to Gatlinburg, TN coming up April 25-29 and everyone has been so excited about going in the "rock star" bus. If I don't get this resolved before then, I'll be sleeping on the couch for a LONG time! :eek:

Alek&Lucia
04-12-2010, 02:56 PM
Michael,

Try here:

http://www.prevoman.com/Pages/Manifold/Manifoldpg1.html

http://www.prevoman.com/Pages/Manifold/Manifoldpg2.html

http://www.prevoman.com/Pages/Manifold/Manifoldpg3.html

Alek

Jon Wehrenberg
04-12-2010, 04:49 PM
Michael,

Thanks to Alec you now have a picture of what I suspect is the problem. The stack of small valves with the red caps is where the problem is suspected. The faulty valve or coil is the middle one, or the third one down.

In another thread Tom posted a picture of the parts as they look. That thread involved Elliott's Marathon entitled "Front won't go up or down", post #36.

I would start by pulling the "C" clip or retainer (use a tiny screw driver and be careful because the clip may fly away), remove the section with the wires (I think held by a small phillips screw), and set the coil or the box shown aside. I think that is what is bad.

Remove the coil from the #3 or #4 position (I picked these because you can raise the bus manually so I know they work) and reassemble the wires and coil back on the middle valve stem. Use caution pushing the "C" clip back on because it will fly away easily.

Start the bus and set the controls for the driving or road position. It should work. If you want to talk on the phone eight six five three two nine zero four six seven. I will be home all evening.

JIM KELLER
04-13-2010, 06:25 AM
WHAT..... Who gives someone their phone number written out in words !

michaeldterry
04-13-2010, 08:34 AM
Michael,

Thanks to Alec you now have a picture of what I suspect is the problem. The stack of small valves with the red caps is where the problem is suspected. The faulty valve or coil is the middle one, or the third one down.

In another thread Tom posted a picture of the parts as they look. That thread involved Elliott's Marathon entitled "Front won't go up or down", post #36.

I would start by pulling the "C" clip or retainer (use a tiny screw driver and be careful because the clip may fly away), remove the section with the wires (I think held by a small phillips screw), and set the coil or the box shown aside. I think that is what is bad.

Remove the coil from the #3 or #4 position (I picked these because you can raise the bus manually so I know they work) and reassemble the wires and coil back on the middle valve stem. Use caution pushing the "C" clip back on because it will fly away easily.

Start the bus and set the controls for the driving or road position. It should work. If you want to talk on the phone eight six five three two nine zero four six seven. I will be home all evening.

Jon - I think you've succeeded in supplying simple, concise instructions that even a brain damaged reprobate from the shallow end of the gene pool like me can follow! My next opportunity to "play" with the bus will be Thursday afternoon/evening. if we run into something your excellent instructions don't cover (or we can't figure out) we'll call you (the number is BR-549, right?) :D

Just for nuttin' - we rode by the lot last evening on our way somewhere else and glanced over at the bus (we always gaze lovingly on her whenever she's in sight) and noticed that her "butt" was still raised at approximate ride height even though it had been several hours since I had manually raised her up and then shut down. It makes me wonder if my very technical procedure of tapping on the Norgren valve and each of the 5 electrical valves with the butt of the large screwdriver I used to open the compartment resolved the issue! (Don't worry - I actually know better - but it was a fun thought!) :p

Jon Wehrenberg
04-13-2010, 08:56 AM
It could have worked.

The solenoid valves when energized cause the 3 and 5 port Norgren valves to "shift". They go from their normal position to an open or closed position because the air passing through the open solenoid valves pushes on a plunger in the Norgren valves. The simple act of adding air to an air bag via the leveling system involves the opeing and or closing of several air valves. If one gets stuck, whether it is the 3 or 5 port valves or the solenoid valves the bus could fail to raise or lower as desired, or air could leak out when you don't want it to leak out or you cannot get the bus to automatically raise to the ride height.

But you have more than one problem and unless you want to spend an exceptionally large amount of money providing on the job training for a technician you are going to have to resolve the main issue, and then seriously consider going the rest of the way by bringing what I suspect are 15 year old air bags and valves up to date.

But in the meantime tapping a valve that probably hasn't been exercised much may just allow it to function. One thing you need to consider and understand is these buses are reliable if used often, maintained to a schedule and fixed as soon as a single problem arises. When a bus sits for extended periods, when it is not maintained, and when problems mount the diagnosis process is very difficult. I don't know this to be a fact, but I suspect you may have contributing issues and if my suspicion is correct moisture in the aux air system may be contributing to lazy valves or stuck valves. I change my dryer every 2 years and I drain my air tanks every 5000 miles. People who do not keep the air systems dry can create issues that actually frustrate logical diagnosis methods. I hope your problem is not made more complex by such issues.

FWIW you can have all the air bags replaced for about $2500, all Norgren valves for about $1300 and you will have what amounts to a brand new suspension system.

michaeldterry
04-13-2010, 09:07 AM
It could have worked.


FWIW you can have all the air bags replaced for about $2500, all Norgren valves for about $1300 and you will have what amounts to a brand new suspension system.

If I can just get this immediate problem resolved and make the family trip to Gatlinburg at the end of this month, I think that will be my next bus related "investment" (sooner rather than later). It makes sense to me! Who would be your choice vendor to have this work done? Prevost - Nashville (Goodlettsville)?

Jon Wehrenberg
04-13-2010, 09:20 AM
With all due respect to Prevost, they have adopted a policy of charging much more to do remove and replace jobs than is reasonable. I would suggest you buy the air bags and valves yourself through Prevost, who ironically has good prices on those parts, and then shop around to determine who will be best for you to do the work. If the vendor you select will order for you that will help insure you get the right parts, but they need to be compensated if you expect them to pay for your parts.

I apologize to those sponsors if I have forgotten you, but I do know from personal experience with them that Russell Coach may work best for you because of their proximity, but you should not rule out Coach Worx or Parliament. When you are in Gatlinburg you are only about an hour from Russell. There may be others I have forgotten, but compare prices, see who best suits your needs and I think you will be satisfied.

Keep in mind the numbers I recited above are only for remove and replace, and if there are other things found when the techs are under the coach, it will be in addition to those estimates. I wouldn't hesitate to add brake chambers, possibly hoses and I would look hard at the brake pads, linings and hub seals, all service items that may or may not be needed, but which will make a lot of sense to do at the same time.

michaeldterry
04-13-2010, 02:51 PM
Jon - do the jobs you outline require access to a pit? If not, that greatly expands my options for selecting someone to do these repairs. Ordering any needed parts from Prevost is not a problem, as long as I have the correct part numbers. I would want whomever I select to do the work to review/check my parts order list and verify that I'm ordering what is needed before I "pull the trigger."

Jon Wehrenberg
04-13-2010, 02:58 PM
A pit helps marginally, but is not required. I changed my first set of air bags and Norgren valves on a barn floor in sub freezing temps.

But....whoever does this has to block the bus up properly. I wouldn't consider anyone except the companies I mentioned and maybe a few others if they could prove to me they have the expertise to explain in detail exactly how the Prevost suspension system works. When POG was in the early years there were a great number of posts by owners who had been screwed badly getting issues with their bus suspension repaired. You can avoid becoming one of those owners by sticking with proven experts who charge fair prices.

I'm sending you an email.

parksincpp
04-15-2010, 10:44 PM
Michael- You just crack me up. Your body and your voice might be screwed up but there is nothing wrong with your brain. Your sharp and witty as always.

michaeldterry
04-16-2010, 06:59 AM
Michael- You just crack me up. Your body and your voice might be screwed up but there is nothing wrong with your brain. Your sharp and witty as always.

Thanks Scott & Cyndie! However, your comment may only serve as evidence that your threshold for "sharp" is way low! :p On the other hand - it also says you can never underestimate a brain damaged "handicripple" with an attitude! ;)

michaeldterry
04-16-2010, 07:10 AM
By the way - I want to report that, with substantial instruction, patience, and moral support from Jon, we were able to swap the valve coil positions for the Norgren yesterday evening and Evangeline is back to being able to achieve perfect, level ride height automatically without breaking a sweat! This work around gets us safely back on the road, but thanks to all I've learned from the braintrust during this experience, I am now motivated to have the suspension gone over completely with a probable replacement of the air bags - at least! And sooner rather than later! Thanks again to all of you who always step up to offer guidance, knowledge, experience, and support as I continue my "education". Thanks especially to Jon Wehrenberg for his invaluable assistance /guidance on this issue!

truk4u
04-16-2010, 07:54 AM
Michael,

Wait until you get his bill, you'll think Prevost is a bargain!:p

ajducote
04-16-2010, 07:55 AM
Michael,

That is great news. It sure is nice to have people like Jon to help out and make things that seem so hard, look so easy. Simple fixes are only simple if you know the tricks. This brain trust called "POG" knows a LOT of tricks that sure make owning a bus a lot easier on the mind and the wallet.

Jon Wehrenberg
04-16-2010, 07:57 AM
When a coach owner has a problem there is a world of difference between diagnosing it and coming up with a way to cure the problem remotely as we do on these forums, compared to having the bus near at hand. Michael and I got lucky.

In Michael's case he provided several critical clues that were caused by an unrelated problem, but made the diagnosis of the problem somewhat easy. We are not always so lucky because often problems do not have other clues that narrow down the area where the defect may be. I can make a general comment applicable for all of us who post problems here seeking solutions. Do as Michael did and tell the whole story. It may not seem important, but to narrow the search for the problem every little detail becomes a part of the puzzle.

For anyone that is following this thread, Michael's problem was the bus would not go to the driving height. He could get it there by manually raising the coach but it would not go there on its own. He stated his back end would sag down and he had to raise it using his leveling system.

That was the critical piece of information. Because he could raise the rear of the bus it proved the Norgen valves which allow that were functioning manually, but when he wanted them to function so the ride height valves worked (they automatically maintain the driving height) and they would not. On later model coaches with the 5 valve manifold on the steer compartment rear wall the center solenoid valve sends an air signal to the 3 five port Norgren valves to open the air path to the air bags through the ride height valves. His clues led to a failed #3 solenoid valve, and most likely the coil was bad.

If any of you experience this problem, which is not uncommon, swap the #3 valve electrical coil with any of the others and your ability to go to the driving position should be restored. The only times the other valves come into play is during leveling such as in a campground. The reason that coil is likely to fail before all others is because the #3 solenoid valve coil is energized any time the key is on and the bus is in the driving position on the leveling system.