Oil Reservoir Tank

[phorner]

Several days ago, I noticed some oil leakage which was almost directly below the rear bumper mud flap. The oil kind of looked fresh, not used, and I couldn't find a likely place for it to have come from.

Opening the engine bay doors revealed a very small amount of oil in the area of the OTR compressor. How did it get there? Then I noticed that the oil line from the oil reservoir tank was wet with what appeared to be oil, and a small drop had formed at the bend of the hose.

Out comes the flashlight and a close examination following the trail leads me to oil presence on the outside of the oil reservoir tank where it comes into close contact with the rear cap. Crap, the tank must have developed a leak!

So, I need to first drain the oil out before I can remove the tank, no problem, just remove the drain hose, place a gallon container under the tank and open the valve. Easy project so far.....

Open the valve and out pours..... WATER!!!:eek:

And not just a little...... almost a half gallon before I see any oil draining.

WHAT THE ???

Well, apparently, the last time I had the cap off, I became distracted and LEFT THE CAP OFF!!!

So.... when we had the nice heavy rains the water appears to have filled the tank to overflowing, with the water displacing the oil of course, so the oil slowly leaked out the top of the tank, down the side of the tank, followed the drain hose to a low point where it dripped off onto the bus frame and ultimately the ground.

Big lesson learned here. I decided to remove the tank for inspection and cleaning, which is not real bad but then again somewhat awkward to remove. Luckily, we don't live in an area subject to hard freezing or the potential for the water to split the tank would be real. Of course all of this could have/should have been avoided if I had paid attention to what I was doing.

You can bet that cap will be on before I even install the tank.

PS: And a split oil reservoir tank due to freezing would be NOTHING compared to an engine oil pan contaminated with nearly half a gallon of water had I needed to add some oil without realizing the contents of that tank!

[Pete]

Paul, is that the original tank? On both of my coaches, an 85, and 95 now, it is a square metal tank that holds a couple gallons of oil.

First time I have seen a plastic one.

[Kevin Erion]

I removed mine on both the 99 and 01. I have never had to add oil between oil changes so what is the need?
This would be another story if I had an 8V92 or I was a paid driver going 15 to 20000 miles between oil changes.

[phorner]

Pete,

As far as I know, that's the original tank, and has a Prevost decal on the bottom.

I have also never had to add oil between changes.... but I like having that extra capacity just in case I need it some day.

I posted this to hopefully keep someone else from making such a bone-head mistake.

My guess is that most of the water entered the open tank when we had a 12" - 14" rainfall last December while I was in NJ, and of course we've had several smaller rain showers since then.

[ajhaig]

We never had to add oil between oil changes in our 1991 Marathon - 8V92 (probably because we changed the oil more then we needed), but I would always have the oil reservoir tank drained and re-filled with fresh oil when we had the oil changed.

[GDeen]

We never had to add oil between oil changes in our 1991 Marathon - 8V92 (probably because we changed the oil more then we needed to), but I would always have the oil reservoir tank drained and re-filled with fresh oil when we had the oil changed.

Ditto on mine for the short time I have owned....did learn that the tank only holds about 9 qts rather than the 10 qts the manual states:eek:

[sawdust_128]

I have the square tank seen in the upper right of the picture.

6010

On the right side, toward the front of the tank is a glass view tube. It tells you the level of oil in the tank and would show if there are layers of other things like water in there. I am headed to the coach and will try to get a picture of that.

Checking that view tube has become a part of my standard checking. I want to make sure that the confidence I think I have because of carrying additional oil is justified. I never thought about it as getting contaminated before.

Here is the condition of the resevoir tank cap when I took possession of the coach and the reason I started always checking this. It does have a breather hole in the center of the cap.

6011

[Will Garner]

Paul,

When I first read your posting I said to myself, "Liberty." Of course had I given voice to that comment I'm sure I would have heard something from Jon.

My tank is steel with a sight glass tube. I imagine getting my steel tank out would be about as much an adventure as getting out the Surge Tank for the cooling system. The tanks are about the same size and shape. I kn ow the pain of getting the Surge Tank out as one of my fitting elbows sheared off when changing the small hoses. So I took the whole tank out, had it bead blasted and powder coated. By the way, for any of the old 8v92 equipped coaches, I had to partially rotate and slide the tank all the way to the right side of the engine bay before it would come out.

All in all a fun project.