Author Topic: Bus leveling slowly  (Read 1967 times)

Offline travelingfools

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Bus leveling slowly
« on: April 22, 2012, 12:59:05 PM »
My bus seems to level very slowly when I'm going down the road. It does level but sometimes will take a minute or two.  Any ideas / things I should check ?
John P, Lewiston NY   1987 MC 9 ...ex NJT

Offline gus

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Re: Bus leveling slowly
« Reply #1 on: April 22, 2012, 04:10:11 PM »
John,

The air bags don't level the bus, they just keep the distance between the axles and chassis constant.

This has a built-in time delay so it doesn't constantly keep moving back and forth underway.

This was to keep the bus stable when loading/offloading passengers and cargo, nothing to do with keeping level with the horizon.

But maybe you already know all this?
PD4107-152
PD4104-1274
Ash Flat, AR

Offline Stormcloud

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Re: Bus leveling slowly
« Reply #2 on: April 22, 2012, 07:21:27 PM »
My MC-7 had a rear corner seemed to take 'forever' to come up first time each day, then it quit filling altogether. The leveling valve was absolutely full of crud.

When I bought the bus, the air system maintenance was performed at a shop in the city where I purchased it, prior to me driving it home. The mechanic said there was a substantial amount of goo came out of the wet and dry tanks. Undoubtedly, some got further along in the air system and was plugging the screen in the leveling valve. The screen can be cleaned and re-used, but I replaced the valve instead.

Mark
Mark Morgan  
1972 MCI-7 'Papabus'
8v71N MT654 Automatic
 Brandon, Manitoba, Canada in summer
 somewhere around Yuma, Arizona in winter

Offline RJ

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Re: Bus leveling slowly
« Reply #3 on: April 22, 2012, 10:25:39 PM »
John -

MC-8s & 9s are notorious for "cornering on the rub rails" because the factory did not install any anti-roll bars in the suspension system.

So it takes a little bit before the leveling valves respond, and then a little bit more for them to bring everything back.

Mark's comments are valid - may be a cruddy valve on one side.

Leveling valves are relatively (for a bus) inexpensive, once replaced, with good system maintenance you'll probably never have to do it again.

FWIW & HTH. . .

 ;)
RJ Long
PD4106-2784 No More
S13406 1978 MC-5C Converted 6V71/MT-644
S14947 1980 MC-5C Shell 6V92/HT-740
Cheney WA

Offline travelingfools

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Re: Bus leveling slowly
« Reply #4 on: April 24, 2012, 06:26:36 AM »
sounds like I may be operating correctly after all.. Where would I find the leveling valves ?
John P, Lewiston NY   1987 MC 9 ...ex NJT

Offline bevans6

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Re: Bus leveling slowly
« Reply #5 on: April 24, 2012, 07:25:57 AM »
Attached to the axles with little struts, two on the rear axle and one in the middle of the front axle.  Not sure if the tags have leveling valves or not.

Brian
1980 MCI MC-5C, 8V-71T from a M-110 self propelled howitzer
Allison MT-647
Tatamagouche, Nova Scotia

Offline travelingfools

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Re: Bus leveling slowly
« Reply #6 on: April 24, 2012, 12:28:21 PM »
Gotcha...I assumed that what those were...
John P, Lewiston NY   1987 MC 9 ...ex NJT

Offline Stormcloud

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Re: Bus leveling slowly
« Reply #7 on: April 24, 2012, 02:30:07 PM »
Not sure if the tags have leveling valves or not.

No leveling valves on the tags. ( at least, not from the factory. )

Mark
Mark Morgan  
1972 MCI-7 'Papabus'
8v71N MT654 Automatic
 Brandon, Manitoba, Canada in summer
 somewhere around Yuma, Arizona in winter