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Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: johns4104s on January 08, 2010, 05:45:58 AM

Title: Series 71 and 92 Air ox drains
Post by: johns4104s on January 08, 2010, 05:45:58 AM
I was just told that the oil looking drips that come out off these tubes are fuel mixed with carbon. Due to lots of idling. I always though it was oil from the crank case.

John
Title: Re: Series 71 and 92 Air ox drains
Post by: robertglines1 on January 08, 2010, 06:17:28 AM
hate to step out first...I understand the air box is a pressurized air system for the engine...the only thing that could come out is condensation and some oil that may have entered from leakage from blower or turbo...the fuel enters system after the air box...
Title: Re: Series 71 and 92 Air ox drains
Post by: bevans6 on January 08, 2010, 08:31:32 AM
If the seals in the blower and the oil rings on the pistons are in great shape, then the residue should be a mix of unburnt fuel that came out of the combustion chamber, moisture, and some oil from seepage.  But excess slobbering can be bad rings, bad injectors, low compression causing poor combustions, leaking blower seals, and probably an excess of bad karma, or a fresh pave job on your driveway that needs seasoning...

Brian
Title: Re: Series 71 and 92 Air ox drains
Post by: Van on January 08, 2010, 09:18:33 AM
If you are dropping oil from these, and not sure how much, hang two empty 1 gallon milk jugs under the hoses to monitor the amount (if any) of oil being ejected from the oil drain hoses. As was said in a previous post, the AB drain tube are a good indicator of an existing or developing engine problem,Blower seals, head gaskets, injector tubes, oil rings, piston problems etc .At idle the check valves should be open, under way they should be closed. I am not an expert but have learned alot fom the masters here, and from hands on experience caused by my on going engine problems. Good luck! ;)
Title: Re: Series 71 and 92 Air ox drains
Post by: johns4104s on January 08, 2010, 12:19:55 PM
I am not having (touch wood) any pavement drips etc, But what I do see is is a slight oily solution at both drains (only at the tube opening) On my 671/4104 I had the oil collection system which I will swap over to my 8v92T, Which consisted of a one way check valve for each slobber tube/hoses /a collection tank complete with breather and a special air filter/breather to keep the oil from being pressured out of the collection tank.
All these years I assumed it was oil from the crank case (which it may be from on some warn out engines) but in my case I have been idling an awful lot (due to my skinner valve playing up) and on enquiring I was told it would be unburnt fuel mixed with carbon and oil gook from excessive idling.

John