A Picture Tells 1,000 Words...

We've encountered a bit of a set back on our way to south Florida so we back tracked north to Marathon FL (we were just here last week for an oil change). Last night when we arrived at Marathon it only took about 20 min for the bus to settle into it's "full lean posistion."

The tech has more or less rulled out any problems with the Prevost side of the air system, they have isolated the Prevost system from the house side of the air system to confirm this in an overnight test.

On a separate note, I noticed this afternoon that the brake lights are stuck on. Any thoughts on what could be wrong with them? I want to show off by fixing the brake lights while the Marathon guys deal with the air system!

AJ

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Originally Posted by ajhaig

On a separate note, I noticed this afternoon that the brake lights are stuck on. Any thoughts on what could be wrong with them? I want to show off by fixing the brake lights while the Marathon guys deal with the air system!

AJ

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The first place I'd look would be the stop light switch - a small valve screwed into one of the ports in the foot valve, you can use a test light to see if both the wires have power only one should be hot unless the brake is applied. You can remove one and check to see if the stop lights go out. Your foot valve is mounted directly below the treadle (brake pedal) in the floor. I'll post some possible valve photos tomorrow when I get to work. A new stop light switch should run you between $20-$25.

AJ.....I seriously doubt the house has ANYTHING to do with the leans.

Your problem is on the RH rear. Verify the three air bags (one on the tag and two on the drive axle) are not leaking. That is immensely easier said than done, but a coach that leans quickly has a leak likely to be heard with a stethoscope.

If you can prove the air bags are leak free, then check the five port Norgren valve ahead of the drive axle, on the forward drive axle bulk head, either behind the fender liner or towards the middle, and if that checks OK look at the three port Norgren on the frame on the RH side between the tag and drive.

If the five port valve is leaking it may be heard leaking from one of the valves in the steer compartment.

Let me really stick my neck out here. I cannot conceive of anything on the house air circuit that can make your coach lean. You can have zero aux air pressure and the bus should not lean. If the tech disagrees, get on the phone to Prevost because he does not understand how the system works.

Ditto what Jon said, as usual he is Jon-nie on the spot and spot on.

Jon,

What you are saying makes perfect sense to me based on everything I've read regarding leaning coaches. What has me confused is that last night the coach went "down" very quickly and tonight she's standing proud, not a hint of leaning.

Is it possible to have intermittent leans?

AJ

AJ I had the same stop light problem a year ago. I went to Prevost Mira Loma to have it checked. They replaced a square clear plastic circuit breaker in the panel above the engine. I am not sure it is called a circuit breaker. There are 3 or 4 of them in a row inside the rear panel. I am not sure but I think they replaced the second one from the right. Whatever this part is called, it is plugged in with a retainer to keep it from comming out. Hope someone jumps (JON) with better info. Darrell

AJ, I'm sure you've heard this before, but the temperature will often impact when/if the bus leaks. My leaks only showed up when it was really cold.

I've also had times where it seems like there might get some debris in the valve or something and things lean. Then bringing the system down, the up again (sometimes a couple of times), seems to clear it, and it's fine.

Ray

AJ, cold will affect it, and as Ray points out it can be an intermittent or one time event. If you can make the Sevierville rally Hector will walk everybody through the basic concept of the leveling system so there will be an understanding of how most coaches work. There are so many revision levels, different designs and converter installed features it is impossible to specifically teach your coach, but you will come away with an understanding of the system in general.

Does that particular vintage coach use or have manual leveling valves? It is also possible that the o-rings have not seated properly when the valves were used allowing the bags to leak back through the manual valves. You can usually rebuild the Bendix Westinghouse valve that was used with 2 or 3 o-rings for a total cost ot .50 per valve

AJ and Darrell,

My brain did not kick in when Darrell mentioned the fix that was made on his coach. Hector and I were PMing this AM and the light came on.

Some coaches have a circuit to engage the brake lights when the Jake or the retarder is in use. When you have either the retarder or the Jake Brake on, and you let off the gas, the retarder or Jake engages and that brings on the stop lights to warn drivers following that you are slowing down.

I have not looked up any electrical diagrams yet, but on my coach for example (a 96 XL shell) relay 76 would be the one to engage the brake lights. This occurs without any use of the foot brake, and Darrells description suggests to me he has an earlier shell than a 96 which uses the black Bosch relays and his uses the P&B style octagon base realys.

AJ do not try to confuse by overcomplicating. Very simply something wore out and began to leak, chase it down and repair it:)

AJ,

Our case of the left rear leans turned out to be a brass connection (cracked) from the drive axle air tank to the tag. Mira Loma searched and searched and said it was either the tag Norgren or the tag air bag since it didn't settle with the tag dumped. So we arragned for them to replace the airbag. Still leaned. So, I obtained a Norgren valve for later install in Quebec. Prevost Quebec found the leak almost immediately last October and it was NOT the Norgren.
We also have sticky brake lights when its cold ( below 50). It IS one of our brake switches. When we leave tomorrow for Tucson for a Country Coach rally, Chris will test it while I hit the brakes to see which one it is. If Tucson Beaudry's doesn't have one, maybe we will zoom over to Mira Loma when we get to Indio.
Our friends just don't understand RV's or busses. I tell them to put their houses on wheels and watch what shakes off.:D

Jim / Chris....I think on your bus you have what Prevost calls bladder tanks. They are tanks solely connected to the air bags, the purpose of which appears to be to provide additional volume to the air bag portion of the circuit.

AJ does not have any tanks between the Norgrens and the air bags. But your advice should be noted by all others with your vintage coach because if the problem happened once, it could happen again.

When it rains it pours...

If a coach is leaning, as ours is right now, could that affect the preformance of the refrigerator?

If you have an ammonia refrigerator it needs to be level. If it uses LP gas it is ammonia.

If it is a regular freon refrigerator it just needs to be somewhat vertical, and only so the compressor oil will stay pretty much where it belongs.

AJ it has been my experience that you would have to be a little more unlevel before the fridge reacts.

Find a level spot and dump all the air bags all the way down till you straighten it out.

Get out the squirt bottle with soapy water, bet you'll find the leak.

AJ,

I'm assuming it's runnning, but not cooling sufficiently.

If you've already haven't done so, check the air filter on the bottom of the refrigerator. Clogged it will really degrades the performance. This is the easy fix.

MIke

Thanks everyone... Mike - indeed, the refrigerator is running, just not cold.

I've put Sarah in charge of getting the refrigerator resolved, which should be interesting (I hope Marathon doesn't kick us out).

With respect to the leans, the tech now thinks we have a problem with the 5-way valve (as Jon already identified as the problem), but the service department wants to test all the air bags first.

AJ

P.S. Is it ok to use drano on the shower drain?

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Originally Posted by ajhaig

AJ
P.S. Is it ok to use drano on the shower drain?

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AJ, I would say NO. I don't think you want to use any caustic products like Drano on your pipes or have it in your holding tanks? :eek:

But I am a newbie, so wait for someone more knowledgable to give you their advice.

Gary S.

AJ, here is a clue as we spoke earlier. If it leans one time, but not another tell Marathon that unless they can be sure the air bags are the self sealing type there is a high probability the only thing they will accomplish is deflating your wallet. It is not the air bags if the leans are intermittent.

Leans - The air bags passed the leak test. We have a new five way valve, aux air pump & pressuere switch. So far so good... time will tell.

Fridge - Removed from coach and a new relay switch installed.

Brake lights - New pressure sensing switch.

Shower drain - Due to the coach leaning.

We may be on our way!