Level LOW

[bigred]

Hello Gentlemen!I recently bought a 1994 Prevost .It is a beautiful coach,but I don't think "tender loving care "was part of the previous owner(s)vocabulary.I knew the coach had some problems so I didn't get  taken by surprise to badly.I wonder if any one can tell me of a way to check the four position Level Low switch.In addition to the Level Low system.this coach is equiped with an automatic leveling system supplied by Country Coach which seems to be working but is slow,but can not get bus to go to drive highth.I replaced the center Solinoid coil on the solinoid bank but it didn't help.I am planning on finding a 24v power source and running it to the solinoid bank .This will tell me for sure if the air system is working.These coils are all 24v.I was going to take the switch out and check it but this seems like a major operation ,but it seems that if the automatic air is working and the bus air is not ,I really think this is an electronc thing.Any advice would sure be appreciated.You guys may get tired of hearing from me before I get old" Money Pit" on the road.By the way,the sn is 2p9m33409p1001723.

[Jon]

Big,

These folks are pretty smart and offer a lot of help, but since most do their own conversions from seated coaches there is not an abundance of expertise on the level low system.

I don't want to see you leave this site, but to supplement it with http://prevostcommunity.com/index.asp where you can get very specific information from people that not only know the chassis but the conversion also.

[luvrbus]

Yours being a Country Coach I have seen some weird wiring so I would call the Country Coach service center with the serial number @541-234-2167 that is the go to place nice folks

Ron Lee does repairs and parts for the Country Coach they are not completely dead, it probably won't be long till they start manufacturing coaches again IMO


If the switch is bad they will not air up in the D position. Jon's board does have some good people that know about the system if the converters haven't done their thing on the system like yours ? does the light stay on or go off in the D position

good luck 

[Jon]

The level low system is very easy to diagnose, regardless of who the converter is, but often we are finding a poorly maintained pneumatic system loads with moisture from the aux air compressor and screws up the protection valve at the converter air connection. Then the valve doesn't open fully (or at all) when the brake system pressures reach 75 PSI. It appears to be a level low problem but can be the protection valve. However, chances are good if the protection valve is screwed up with moisture the Norgren Valves are screwed up as well making a problem created by multiple sources.

Lately we are having an epidemic of ruined Norgrens due to wet pneumatic systems.

[bigred]

Actually,the light stays on.The funny thing is ,the light stays on even with the switch off and the 24v and 12v house switches off.When I bought this thing they told me that it would raise to Drive hieith but it took a long time for the air to build up.This is not what I am finding at all because the air presures jump up quickly.It just won't raise the coach like it is supposed to.That is another thing that kind of makes me suspect the switch because the people I bought it from would keep playing with the "raise-lower" switch and it would finally raise.I can not hear any of the solinoids pull in .That is why I plan on airing this thing up from an off board air supply then jumping a 24v power source to each one of the solinoids .This way I should be able to tell if the air and the solinoid bank is working as it should .If it does,then my suspicion of the switch being bad will be confirmed.If you guy's see any thing wrong with  this theory,feel free to shoot me down.I'm a big boy !I can take it!

[luvrbus]

Some of the level low on certain year models are wired through the parking brake with a inline switch to prevent operation till the parking brake is applied yours may or may not be 

I tend to agree with you about the switch with the light staying when in the drive position

[Jon]

Big Red,

Don't make this more complex than it needs to be.

Have someone operate the level low switch (and the up and down button) and you should be able to hear the solenoid click. If you want to confirm air is passing just crack the fitting at the solenoid bank.

If you have a coach that has had moisture in the pneumatic system your problem can be as simple as a failed, corroded, or lazy protection valve (on the rear bulkhead in the steer compartment) or worse, corrosion in the Norgren valves that control the system. If you have had moisture in the system, especially the accessory system you have a complex problem that can have far reaching consequences.

Your description is not specific so I don't know if the coach won't rise to the driving height or if you cannot raise the individual positions. Each problem has limited causes, easily identified.

http://prevostcommunity.com/PDF/Prevost%20Leveling%20System%20Diagnosis%202-2-12.pdf

[bigred]

Actually Jon,I can't get a response from either of the Prevost provided controls.The Country Coach system located on the upper console(above the windshield)will actually level the coach .I know the aux air does have a leak as it will leak down over night.The dry system that operates the brakes will stay charged for weeks.Do you know how the aux compressor can be checked ?It appears to work off 120v.Does it only work off shore power?Or should it work any time air pressure is needed in the aux system? There used to be a bus machanic in the Asheville N C area .He actually had a repair shop at one time ,but closed it.Would really like to talk to him if any one knows who he is or how to locate him!               

[luvrbus]

Jon, his light should go off momentary at least when he switches to the drive position I have the schematics for the Country Coach but I am having hard time trying figure out how they have the system tied together that seems to be a Country Coach system not a HWH.
I agree with you it should be simple with the switch in the drive position the drive control solenoid supplies air to all 5 way three position air control valves letting the height control valves function that is happening for him,me after this much time I would on the phone to tech support

good luck

[Jon]

Big Red,

You need to talk to Country Coach owners who understand your coach. You went beyond my grade level when you said the CC system works but not the level low. CC did their own thing unlike most other converters in that they integrated their systems with that of the Prevost system, not only on the suspension as you describe, but other areas such as cruise control.

When a typical level low system fails to function it is very easy to isolate the problem. Whether it is electrical or pneumatic an owner can quickly figure out where the problem is. In your case you say the CC controls can level the coach. That rules out all but one of the solenoid valves as part of the problem. If the ride height solenoid valve is energized and open when you select the driving position you can rule that out as part of the problem. If not you have to find out why it isn't being powered and that is when you have to discuss this with someone who understands the CC interface with the Prevost system.

The speed at which your coach goes up and down can be lack of air flow through the protection valve, too much weight on the front axle as some CC coaches had that issue, or Norgren valves (the 5 port valves Clifford mentions) that might be sludged up by the previous owner who did not maintain the pneumatic system or even all of the above.

I can tell you one thing..........if you go to a mechanic that doesn't understand the system you are in deep manure. There is a great shop southwest of Knoxville TN run by Jeff Rowe and he has serviced CC coaches for years when he worked at Buddy Gregg's. He is the type of guy you need to do the hands on work. You will not be paying him for on the job training.

http://www.easttennesseeluxurycoach.com/index.html

I have no relationship with Jeff other than I know him. A lot of Prevost owners have raved about his work.