Prevost kneeling

[jok]

Need help again. My 1990 XL has a kneeling feature that has lowered quickly and raised verrrry slowly since I bought it in 2000. I figured it was the nature of the beast. Yesterday I saw an MCI commercial bus in a parking lot kneel and raise again. It raised as quickly as it lowered. The driver said his company has replaced the valve that controls the kneeling on all their buses. Does anyone know if the Prevost uses a similar valve and if so where is it located. Thanks in advance for your help.

John

[Sammy]

I ran a fleet of H3-45's, don't know everything but will check my library for you.
Might be a sticking Norgren valve, a bad solenoid, but I'll see what I can find for you.
I'll post any info that might help. 

[Ray D]

I have an 89XL and it goes up slowly also.  All others I have seen in this class also go up slowly, don't know if there is an adjustment for this, but I would be interested also.

Ray D

[rip]

I have a 85 Prevost and mine is also slow going up. I rarely use mine so I never looked into it if there is a problem or not.
      Don

[Skykingrob]

Hi John
I have a 91 LeMirage XL. I too had the kneeling feature. My coach lowered fast and raised nearly as fast as lowering.

John, the valve in question is directly above the front axle, in the very center of the coach. If you block up the coach when it is up, crawl under the spare tire storage from the front, there is an area to sit up right behind the front axle.

Caution: Do not crawl under without blocking well. If you don't, there will be about 5-6" at most under the coach, and you will likely be crushed to death.

I didn't want the kneeling feature in my coach, so I initially blocked the bus when up, then crawled under the bus, removed the valve exhaust tube and replaced with a 1/4" plug. Probabky would work with adjustment of the ride height arm but without it, my bus was 4" to high in the front. I was worried it was overinflating the airbags, so I contacted Prevost-Nashville and got another valve that was non-kneeling and replaced the kneeling valve. The cost was $56 including shipping. My bus no longer kneels and I have used the dash switch for other things.

Rob
91 LeMirage XL
Missouri

[RTS/Daytona]

The way RTS's get thier kneeling feature to raise fast is with a "FAST FILL" valve - this is an "air Piloted" non electric valve with a HUGE flow rate - The same valve that is used with "air starters" - it requires air pressure to open this fast flowing valve - so a regular skinner type solenoid valve (just like you have in your slow raise circuit now) is activated by a switch and when the valve open it supplies "pilot Air" pressure to open the "fast Fill valve"

the GM parts # is 2057331 - I see it in the Midwest Cat for $75 and the Mohawk cat for $173 - But I bet a lot of RTS's out there have already removed the valve and may have them laying around - do you want me to ask on the yahoo RTS Bus Nuts Board ??

The other solution - buy a FAST AIR BAG SOLENIOD from the guys that supply the valves that make the kids cars hop -
see-->
his last set went for $22 + his outrageous shipping of $19.99
http://cgi.ebay.com/ebaymotors/2-3-8-ASCO-12-VOLT-FAST-VALVES-AIR-RIDE-SUSPENSION_W0QQitemZ220139318102QQihZ012QQcategoryZ33586QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

http://cgi.ebay.com/ebaymotors/2-3-8-ASCO-12-VOLT-FAST-VALVES-AIR-RIDE-SUSPENSION_W0QQitemZ220139318102QQihZ012QQcategoryZ33586QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

BUT YOU need a check valve for it to work in your application - These types of diaphram valves allow large / fast flows BUT they can not take pressure in the opposite direction - so if your suspension tank goes down overnight - so will your front air bag

the other solution (although it may sound silly) is to use 2 valves back to back in opposite flow directions - this will also allow you to wire the 2 coil together to get 24V operation ??

Pete RTS/Daytona -- I KNOW leveling system very very well -

[jok]

Thanks for your replys. I will check with Prevost next week about the valve to see if I can fix it with original parts. If not I will look into the RTS system. I am looking forward to have it raise faster. I knew I would get some good answers here. I will keep you informed.

John