Oil In Air Compressor Intake Hose

gus · March 02, 2011, 05:36:10 PM

I found my hose oil soaked today, got about an ounce of oil out of the hose. The bottom of the air box is oil soaked and the air intake hose was soaked and dripping oil onto the valve cover. It is an 8V71 in a 4107 with an oil bath air cleaner.

Only two ways I can see that happening;

>If the oil bath cleaner is overfilled oil could be sucked into it, maybe, but I would think the engine suction would be so much greater the engine would get all the oil?

>Or, maybe the engine is sucking oil out of the compressor when there is no load on the compressor?

Any other ideas?

JohnEd · March 02, 2011, 10:11:27 PM

If you get a water leak into the oil bath air cleaner, my personal favorite, then the oil will float on the water and run out and "look" like an oil leak. Possibility? Clogged drain? Happened after a rain storm? Can't see how you could get too much oil in the reservoir and not know about it. When was it serviced? You overfill it and it will get sucked into the output air flow. You should also see some smoke due to the engine running rich due to the intake air restriction even if it is only one of the three air cleaners that run in parallel. The air is supposed to flow across the surface of the oil and not get percolated up through it as in an overfill condition.

Let us know,

John

RickB · March 03, 2011, 08:38:08 AM

Gus,

The biggest contributor to my oil leakage (the assorted drips at idle that are not coming from the airbox drains) was my compressor. The thing leaked into my air system, onto the ground, into the air and God only knows where else. I don't have the oil bath air cleaner so I don't know if this piece of info will help but I am so glad I changed out my compressor/ I have literally zero leaks coming out of my motor other than the stuff I'm collecting in my airbox drains. Feels good to leave a parking lot after a short idle and not leave a puddle (Knock on wood)

Good luck getting to the bottom of this and keep us informed as to your progress

Thanks

Rick

gus · March 03, 2011, 07:16:45 PM

Rick,

My engine is as leak free as I would ever expect a DD to be, even this leak does not drip onto the ground but puts oil stains on the engine, bumper and hoses. I have an accumulator tank for the drip tubes so it leaks nothing onto the ground.

The leak is in the compressor fresh air intake hose. I know worn out compressors are bad to leak oil into the air output line but this is the first one I've seen with oil in the intake?

My 8V71 has a muffler looking gallon size steel air box bolted to the top of the engine air intake and the air cleaner empties into this box. I would assume the air box would have a standpipe inside it to keep stuff from flowing out of it but, maybe not. Anyway, it seems strange to me that the air supply to the comp is from the bottom of the air box instead of the side?

I haven't yet serviced the air cleaner because I just got the bus but I intend to check it out. There is only one huge air cleaner, not three like for the 671 on my 4104.

I'm hoping Don Fairchild will see this and contribute from his store of DD knowledge.

luvrbus · March 03, 2011, 07:56:09 PM

The air compressor is supposed to be tied into the air horn on top of the blower on a 8v71 you never tie a air compressor into a oil bath on a 8v71 or they have their own air filter bolted on the compressor.
I would chunk the old oil bath and install a ECO system and give your 8v71 some breathing room and better filtering all the DD books I have show the oil bath filters 95% of the air and a good paper filter will filter 99.8% of the air, paper is better lol JohnEd

good luck

trucktramp · March 03, 2011, 08:18:59 PM

Quote from: luvrbus on March 03, 2011, 07:56:09 PM

I would chunk the old oil bath and install a Echo system and give your 8v71 some breathing room and better filtering all the DD books I have show the oil bath filters 95% of the air and a good paper filter will filter 99.8% of the air, paper is better lol JohnEd

good luck

Clifford, tell me more about the Echo system. I want to change my oil bath system over to paper. I googled echo and all I saw was chainsaw information. Where do I find the system?

luvrbus · March 03, 2011, 08:32:49 PM

Sorry about that Dennis it is ECO never noticed I posted Echo it is a good system

good luck

JohnEd · March 03, 2011, 09:12:08 PM

Quote from: luvrbus on March 03, 2011, 07:56:09 PM
The air compressor is supposed to be tied into the air horn on top of the blower on a 8v71 you never tie a air compressor into a oil bath on a 8v71 or they have their own air filter bolted on the compressor.
I would chunk the old oil bath and install a ECO system and give your 8v71 some breathing room and better filtering all the DD books I have show the oil bath filters 95% of the air and a good paper filter will filter 99.8% of the air, paper is better lol JohnEd

good luck

At the risk of looking like I am insisting on staying stupid....I will stay with the oil bath as my optimum performer and heart throb. Paper, I know can get down to a finer particulate...no question. Oil is impervious to getting dirt clogged as it progresses through its maint cycle. I imagine that the air resistance to flow and the filtering performance are the exact same at service time, 50K, 100K or? It filters stuff out by inertia and the micron stuff that weighs next to nothing has little problem getting around the "corner" and not getting slung into the oil,bath. For instance, smoke would not be impeded by any oil bath but you could find a paper element that would stop smoke particulate. We already have one of those hooked on to the exhaust and call it the particulate filter and that is followed with the urea thingy. So the science is definitely there and provable. With the OB you can even double the cleaning interval, as I did with the VW, and all seems to be well. No matter how long I let it go I never found more than an inch thick/deep crud of trapped sand or dust or vegetation in there but I was always impressed at how much it trapped and still kept working. The OB is ancient tech and I understand,from one of your posts that the OB is still alive and well on farm and off road equip, sometimes as an option but available none the less. I was told long ago on this board that the reason the OB was replaced was purely initial cost, labor to service and consumable materials cost associated with service. Time seems to have become the deciding factor, as in the case with aq lot of stuff, but, Clifford, time is what I have and this adventure is a labor of love. I am not a purest but if I can stay with tried and true, and get superior performance for my minimal effort I will stick with OB as my personal choice. Did he just even come close to arguing with "The Clifford"?

Don't worry Clifford...you still walk on water in my book. Just explaining my reasoning to the other guys so I don't look like an old fart stuck in his past and stubbornly refusing to get with the 20th century.

Now what kind of fuel filter can I use that would remain nonrestrictive till change out time? Oh, I know...a centrifugal filter...isn't that like a velocity filter AKA Oil Bath? And don't they use them for engine oil filtering while under way? On a roll here. $:-\$

Ya got me on that helicopter stuff though, Clifford. At least for now. I own a small RC copter and I can fly it but my eyes got so bad I was bouncing it off stuff...by accident. But I will get it out and get a bigger one and study up so we can "talk' next time you fly in.

Still love you Clifford even if you don't answer my PM's.

John

Boomer · March 04, 2011, 08:10:33 AM

The Eco series filters are a Donaldson product. Look for them in the Donaldson parts catalog, on line or get the paper catalog from your distributor. Get the highest flow one that will fit on the bus. The are a completely replaceable unit, no element inside, just replace the whole unit when it's ready. You have to have a filter minder installed in the intake to register the restriction for this, minor item. I love mine. Clifford is right on.

gus · March 04, 2011, 08:06:00 PM

The air compressor intake is not connected to the oil bath air cleaner, it is connected to a steel can on top of the air box cover. My only complaint about this connection is it is at the bottom of the can, I think it should be at the side or top but it is mechanically simpler to use the bottom.

I agree with JE, I am an oil bath air cleaner fan and would never remove one. Don't see any reason to replace a simple, effective system with an expensive one. I think the only reason for changing to paper was to make maintenance much simpler and faster at the expense of the owner!!

I agree it is messy but what about a DD isn't?

RickB · March 04, 2011, 08:43:33 PM

Not actually being there to see what you're describing is there any chance the oil is coming from the airbox?
I will admit I have never seen an oil bath air cleaner so I have no idea whether or not this is feasible but thought I would put it out there. Stuck closed airbox drains, oil backs up in the blower and the blower vanes start spitting it out the top of the blower.
Just a thought gus
Rick

gus · March 05, 2011, 05:16:37 PM

Rick,

On my 8V71 there is a large inverted cone shaped cast housing on top of the air box, on top of this housing is a sheet metal housing that looks like a muffler. At the bottom of the sheet metal housing is an outlet to the compressor.

The outlet from the oil bath air cleaner goes into the side of this sheet metal housing

I presume this cast housing is installed on all 8V71s but this engine is new to me so I'm not sure, all my previous experience is with the 671, a great ole engine.