Leaking Oil Pump cover

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Glen Getchell
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Leaking Oil Pump cover

#1 Post by Glen Getchell »

I at last got my race engine together, and all seems well, except I can not get my oil pump cover to stop leaking. I am on my fourth gasket, and I simply can't get it to seal. I have one of Vic's covers that sends oil to the front coolers. I have used this cover for more than a decade without a problem. But it is now mating to a different third piece. I thought I had it the last time around. No signs of significant leaks till I turned it off. That kind of made sense as there is that oil grove to keep it from leaking. Once the car was off the oil was not be pumped around that grove. I tried snugging up the nuts, and well that just made it worse. Now I have a full blown leak. Again. I bought a bunch of gaskets, but honestly I can see going through them in a couple hours at this rate. Does anybody have a trick to get the oil pump cover to stop leaking. Thanks!

Glen
64Cx2
P.S. This is not a dribble. This is a leak.

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C J Murray
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Re: Leaking Oil Pump cover

#2 Post by C J Murray »

I would get a flat plate/block of steel and use it to sand the third piece with 1500 grit paper to check for warping. You can also check the cover. If you do much sanding I would remove the third piece and confirm that the pump turns freely and smoothly when the cover is torqued. In fact, do you know absolutely that the gears are not holding the cover away from clamping the gasket? I think you should remove the third piece and give everything a very close inspection for flatness and freedom of rotation without binding. I always assemble the pump before attaching the third piece to the engine because problems often occur with the pump assembly.
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Glen Getchell
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Re: Leaking Oil Pump cover

#3 Post by Glen Getchell »

Ya, all of this was assembled prior to installation. Oil pump gears were on the short end of spec, so they should not be holding the plate out.

I think I need to reword my dribble P.S. on my last post. I may have over stated that. It is a very heavy dribble would be more accurate. Enough to leave a small puddle after 15 minutes of running. But its not dumping quarts out or streaming out.

Now with that said, I just pulled it all apart again. The gasket looked fine, and still measures in spec. So I cleaned it up, and put it back together with the same gasket. Remember I said that it leaked after shut off and I tightened every thing up a little, and that is when the above mentioned "heavy dribble" started. I just started it up (I have the fan belt off to get temps up quicker for testing). Let it run for 10 minutes, Got the temp up to 220 MOL reved it up and down to 5K RPM, let it run. I saw no leak while running. As soon as I shut it off, it starts to leak (just like before). This time instead of being proactive and tightening the nuts I left it alone and just laid on the ground and watched. I counted four drips, and a fifth that was non-committal and hung to the plate.

While I don't like any oil leaks. This seems like a livable situation especially considering that the leaks are when the engine is off. While I have never experienced this on any of my other engines, maybe this is some what normal. Is it some times? Opinions? Really don't want to pull the engine and third piece for this.

Glen
P.S. Went and looked at it after writing this post but before sending it. It appears that we remain with what is probably fifth drip still hanging on. So no additional oil appears to be leaking. I started it ran it to 180 degrees revved it back up and down. No leaks. Shut it off, laid on the ground for a few minutes saw one minor drip that was to light to fall and just followed the third piece down, and another building into what appears will be a minor hanger.

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Wes Bender
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Re: Leaking Oil Pump cover

#4 Post by Wes Bender »

You'll have to remove the pump plate to check it, but make sure you didn't block the little return channel that takes oil from the "catch" circle back to the inlet side of the pump.
Some days it's just not worth chewing through the restraints.....

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Re: Leaking Oil Pump cover

#5 Post by Jeffrey Leeds »

If it is truly just weeping - as opposed to leaking - I'd clean the metal faces with some brake-clean, then wipe both sides of the gasket with your finger with Blue Hylomar, reassemble and let it sit for a bit before running it again.
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Glen Getchell
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Re: Leaking Oil Pump cover

#6 Post by Glen Getchell »

Never heard of Hylomar. Is that the same as Blue RTV?

Glen
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C J Murray
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Re: Leaking Oil Pump cover

#7 Post by C J Murray »

Glen Getchell wrote:Never heard of Hylomar. Is that the same as Blue RTV?

Glen
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No.
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Re: Leaking Oil Pump cover

#8 Post by Jeffrey Leeds »

It is a non-setting sealer. You can learn all about it here:

http://hylomar.com/hylomar-product-rang ... compounds/
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Re: Leaking Oil Pump cover

#9 Post by C J Murray »

Permatex has a version also.
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Re: Leaking Oil Pump cover

#10 Post by Jeffrey Leeds »

Would you use repro parts on your 356 Cliff, when you can get the real thing?
;))
< Jeff >

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Dick Weiss
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Re: Leaking Oil Pump cover

#11 Post by Dick Weiss »

After reading all the above responses, I don 't believe it's the pump cover gasket. I make sure both mating surfaces
are flat, check the end-play of the gear shafts--w/the OEM gasket which is approximately .008-.009" thick, and will give excessive end-play/outa specs! W/o removing the 3 (or 4) studs to face off the 3rd piece, I make a .004-.005" thick gasket from brown paper + a little #2 Permatex sealant on both sides to solve the problem.
The endplay equaled w/in specs.

Therefore, no one mentioned the tach shaft seal being in good shape or replacement + the little shim to squeeze it when snugging up the ring-nut--unless you have a non-tach cover. Thusly, when the engine is shut off, the oil will leak will occur and weep around and down the cover's edge. My findings resulted in preventing any leaks.
This also prevents any leaks from the ring nut--or 'venturing' forward on the tach cable to the instrument!

BTW, the 3rd piece's face doesn't get outa shape, but the pump's cover would be easy to lap flat on a plate.
Also, I remake the spacer/bushing between the spiral and pump gear on the drive shaft to refit the bore in the cover
to keep the shafts parallel to each other; You'll see some wear on the gear pitch lines worn on 1-side.
It's usually worn down as much as .010"--should be around .707-.709" diameter.

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Ron LaDow
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Re: Leaking Oil Pump cover

#12 Post by Ron LaDow »

Vic's part is as robust as the Pre Mat part. It is not 'out-of-flat' unless it was caught in the CA wildfires and one of the HOT ones at that.
The timing cover does not go 'out-of-flat' unless it is warped enough that the oil pump gears won't rotate.
You need to take it apart and look. What ever the problem is, it has nothing to do with the gasket sealing. Look again.
Ron LaDow
www.precisionmatters.biz

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Vic Skirmants
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Re: Leaking Oil Pump cover

#13 Post by Vic Skirmants »

I had a situation once with a leaking cover on a newly-built race car. Turns out the bolt at the left lower location was just a smidge too long and therefore prevented it from clamping the cover properly at that location.
But I don't understand Glen's problem: NO leak while running, and then leaking only after shutting down?

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C J Murray
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Re: Leaking Oil Pump cover

#14 Post by C J Murray »

Jeffrey Leeds wrote:Would you use repro parts on your 356 Cliff, when you can get the real thing?
;))
I'm going to check your cheesehead screws smart guy! :P
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Re: Leaking Oil Pump cover

#15 Post by Greg Bryan »

Don't overlook other seals in the are area that could be leaking such as the pulley and the Oil Pressure relief valve cap screw.
Greg Bryan

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