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Oil leak track down

Posted: Mon Apr 16, 2012 8:41 am
by grandfatherjim
End of last summer I noticed more than the usual odd drop of oil leaking from somewhere on the left side of the engine.
The season has started again and we'll be actively camping from June onward, if all goes as planned. Yesterday I backed in to the garage to do some other work and this morning when I went out there was an alarming puddle of oil under it. I had only backed in, then shut off the engine.
I intend to pull the engine anyway for other reasons so now want to fix this leak. It's not the seals around the pushrod tubes; those were all successfully replaced along with the tubes themselves.
Problem is the oil is all over the place so hard to pinpoint the source. I wish I had a pressure washer but don't.
What are the first places I should look? What things should be dealt with as a matter of course when the engine is out? I do have new oil cooler seals on hand.
I want to get parts together before pulling, to minimize my down time. I don't have a lot of spare hours and don't want to miss out on camping...but this leak is too big.
Thanks,
Jim

Re: Oil leak track down

Posted: Mon Apr 16, 2012 9:08 am
by poptop tom
What year is your bus?

Re: Oil leak track down

Posted: Mon Apr 16, 2012 9:13 am
by grandfatherjim
It's a 72 1700 dual carb.

Re: Oil leak track down

Posted: Mon Apr 16, 2012 9:39 am
by poptop tom
I would spray some carb cleaner on paper towels and start wiping things down/cleaning up the best you can. Start up top.

I would look down around the distributor, and oil pressure switch.
You may be able to look (with a flashlight) up past the rear motor mount towards the oil cooler, oil pump housing,
and oil filter to see if you can locate something from there.

Another thing you could do is pull your cooling fan pulley out. You can see the top of the oil pump housing from there, as well as the rear main seal, and some the gallery plugs to confirm that they hopefully aren't leaking.

Re: Oil leak track down

Posted: Mon Apr 16, 2012 8:49 pm
by RSorak 71Westy
I wish I had a pressure washer but don't.
2 cheap solutions, spray it down with brake clean or buy a $9 pump it up yard sprayer at Walmart and put some gas in it and spray it down with this. Either way will remove the oil and leave it clean and dry. Just make sure its not running and there's no source of spark nearby (gas hot water heater in garage for instance..

Re: Oil leak track down

Posted: Tue Apr 17, 2012 4:39 am
by grandfatherjim
I like the pump up yard sprayer idea. I think we even already have one, but I might use something other than gas. Certainly I'll make the effort to clean up as best I can.
The underside of the heat exchanger is covered so I suspect it's above that, but it could be migrating forward or back from somewhere. I suspect it will be hard to spot but am not keen on running the engine without a manifold attached. Maybe I'll try cleaning, running it for a short time, and "quickly" removing the heat exchanger"
Jim

Re: Oil leak track down

Posted: Tue Apr 17, 2012 7:56 am
by Amskeptic
grandfatherjim wrote:I like the pump up yard sprayer idea. I think we even already have one, but I might use something other than gas. Certainly I'll make the effort to clean up as best I can.
The underside of the heat exchanger is covered so I suspect it's above that, but it could be migrating forward or back from somewhere. I suspect it will be hard to spot but am not keen on running the engine without a manifold attached. Maybe I'll try cleaning, running it for a short time, and "quickly" removing the heat exchanger"
Jim
This makes no sense. You find your oil leak without removing heat exchangers. The most important thing here is to clean, then look for fresh oil. Pushrod tube seals you have to *clean* each end of *each* pushrod tube, then run the run the engine warm, then *look*.
Colin

Re: Oil leak track down

Posted: Tue Apr 17, 2012 8:06 am
by grandfatherjim
I will definitely look everywhere I can see. I wrote that thinking that the leak may be out of sight, above the heat exchanger. Pretty sure it's not the pushrod tubes as they themselves aren't oily, but we'll see.
Just in from picking up some Simple Green.

Re: Oil leak track down

Posted: Thu Apr 19, 2012 5:03 pm
by drober23
There are several things on the left side of the engine that could be leaking. Oil Pressure Switch, Oil Cooler Seals, Pushrod Tubes, Valve Cover Leak, and Oil Filter Seal are the ones that come immediately to mind.

The pushrod check is pretty easy, so you probably want to listen to Colin (always a good idea anyway!) and try that first.

Also, sometimes it is good to feel into places that you can't see well. Feel around the oil filter,and the edges of it. If that is wet, try to see if it is wet higher (above where the filter screws on). If it is wet up there, you know your leak may be higher on the engine (like the pressure switch).

Good luck to you!

Re: Oil leak track down

Posted: Fri Apr 20, 2012 6:06 pm
by Amskeptic
drober23 wrote:There are several things on the left side of the engine that could be leaking. Oil Pressure Switch, Oil Cooler Seals, Pushrod Tubes, Valve Cover Leak, and Oil Filter Seal are the ones that come immediately to mind.

The pushrod check is pretty easy, so you probably want to listen to Colin (always a good idea anyway!) and try that first.

Also, sometimes it is good to feel into places that you can't see well. Feel around the oil filter,and the edges of it. If that is wet, try to see if it is wet higher (above where the filter screws on). If it is wet up there, you know your leak may be higher on the engine (like the pressure switch).

Good luck to you!
Advanced Leak Possibilities:

spigots, case nuts, distributor o-ring, gallery plugs, my favorite, and that stupid oil filter housing.
Colin

Re: Oil leak track down

Posted: Fri Apr 20, 2012 7:15 pm
by grandfatherjim
After lots of de-greasing foaming cleaner spray-on super gel, I believe I can see what's going on, and to my (tentative) relief it appears to just be the rocker cover gasket at the lower front corner.
Earlier I was going to post how I don't think it's rocker cover gaskets, pushrod tube seals, distributor O-ring, or oil pressure switch as they all have been replaced pretty recently. But I guess I won't say that now.
Tomorrow's the day for pulling the engine (for other reasons). Maybe first I'll swap in a new rocker cover gasket since I have them on hand, and see how much that reduces the overall leakage. I think there is still a bit at the oil cooler, but that I will deal with once the motor's out.

Re: Oil leak track down

Posted: Sat Apr 21, 2012 7:22 am
by grandfatherjim
Image

Let's see if this works. Should be that if you click on it you will see a video of oil dripping.

Re: Oil leak track down

Posted: Sat Apr 21, 2012 3:12 pm
by grandfatherjim
Image

Well that was easy. Replaced gasket and no drips. First time I've ever had no drips.
Started removing ancillaries in preparation for engine pull and do see some oil on top of the left heat exchanger just where it meets the muffler, which is just below the oil cooler. This is encouraging.

Re: Oil leak track down

Posted: Sat Apr 21, 2012 4:50 pm
by Amskeptic
grandfatherjim wrote:Replaced gasket and no drips.
Is that a badly shrunken gasket? We might need to update our valve cover gasket methodology to include cleaning the valve cover spiffily dry, gluing the gasket to the valve cover with Curil or 3M weatherstrip or hylomar?
Colin
(new skinny gaskets seem to be more prone to shrinkage)

Re: Oil leak track down

Posted: Sat Apr 21, 2012 5:30 pm
by grandfatherjim
Amskeptic wrote:
grandfatherjim wrote:Replaced gasket and no drips.
Is that a badly shrunken gasket?
Yes it is.
Amskeptic wrote:We might need to update our valve cover gasket methodology to include cleaning the valve cover spiffily dry, gluing the gasket to the valve cover with Curil or 3M weatherstrip or hylomar?
Colin
(new skinny gaskets seem to be more prone to shrinkage)
I almost used Hylomar but wanted something a bit thicker and with a bit more tenacity, to hold the cork from siding around as I installed it. I find Hylomar pretty jelly-like which is great later when you want to take things apart, but I ended up using a Permatex form-a-gasket - kind of a light blue colour - that's non-hardening, on the rocker cover side only. This after serious cleaning and drying of the inside of the cover of course.
Not familiar with Curil. Must investigate.