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Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: mwf on November 25, 2007, 07:37:50 PM

Title: oil leak from air tanks between front tires.
Post by: mwf on November 25, 2007, 07:37:50 PM
I have oil dripping from my air tanks between the front tires on my 88 MCI 96A3.  Purchased last year, and have not put on a lot of miles.  Any suggestions about what is causing this, and what I should do about it?
Title: Re: oil leak from air tanks between front tires.
Post by: tekebird on November 25, 2007, 07:46:08 PM
if oil is coming out you have an air leak too
Title: Re: oil leak from air tanks between front tires.
Post by: Frank @ TX on November 25, 2007, 10:20:03 PM
Hi mwf,
Put a sheet of card board under the tanks.
Pull the ring at the bottom of each tank and look for a lot oil mist and drops coming out.
Check the card board to see how much.
If there's a lot of oil then you may be blowing oil past the air compressor rings.
When is the last time you had the AD-2 ( air dryer ) serviced ??
Frank
Title: Re: oil leak from air tanks between front tires.
Post by: mwf on November 26, 2007, 04:36:29 AM
Just purchased the bus in the late spring (did not use at all from May-September), so I have not had it serviced.  From how long it had been since other things were serviced I would say it was a while.
Title: Re: oil leak from air tanks between front tires.
Post by: gumpy on November 26, 2007, 06:38:31 AM
First, which tank? Driver's side, or passenger side?

Where exactly is the oil coming out of the tanks?  Is it coming out of the drains or someplace else?

Is it coming out on it's own, or only when you pull the drain rings?

Are you sure it's oil, and not water w/ rust & crud?

The first problem is the oil itself. Air systems do not have oil in them intentionally. This means your air compressor is probably in
need of replacing. Second as pointed out above is that the air dryer is now probably in need of service due to oil coating the
dessicant. And third, you may need to fix the leak at the tank. Hopefully, if the oil is coming out the valve, then just replace the
valve, about $6 at the truck shop.

Fix the compressor first to get rid of the oil, then service the dryer after you've run it awhile to get most of the oil out of the line
from the compressor to the dryer. There should also be a drain in the rear passenger engine access next to the tag axle valves which
will drain off oil collected in the discharge muffler.