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I've been hunting for oil leaks (eg mentioned here) and have been successful with some, but some were untraceable.  I got smart and bought some of that UV dye that you pour into your oil and then trace the leak using a blacklight/UVA.  We (father and I) traced it to two places: (1) the cover to what I think is an oil sump pump?  (2) an opening for which I don't know the purpose.  We thought their gaskets were meager/thin (pictured), so we cut out gaskets from a gasket material sheet we had lying around.  

Now it's super leaking oil!!  Both places but especially the sump cover.

Perhaps the gasket material is wrong for this use?  I don't know the specific product info, but it's paper-like, please see the photo.  Should I change this for a rubber material?  Or buy gaskets from the manufacturer?  I'll have to do some investigation to figure out what motor and thereby parts these are...

I should note that one of the 4 bolts for the square sump lid was loose and its hole was kinda stripped (we believe from before), so we actually tapped that hole and used a larger bolt there.  For that reason, we were careful not to *super* tighten the screws, perhaps that has something to do with the leak?  Perhaps this means the layer I mention at the end of this post isn't as tight as it used to be either.

Speaking of, I was thinking perhaps the gasket material shrunk after being pressed / heated, so I just tried tightening the few bolts I have ready access to, I noticed that these bolts felt a tad loose.  So I'm going to do the whole pulley removal effort (discussed in that link above) again to access and tighten the top 2 bolts of the square lid.  But it's probably wishful thinking that that'll do it.  Probably should change the gaskets while at it if that's what's recommended...

Last but not at all least, I think the sump has two interface layers: (1a) the outer layer we serviced (1b) but there's an inner layer, see the photos.  Seems like the inner layer might actually be the main leak.  But it wasn't readily apparent how to remove the intervening plate to get to this layer.  Any tips on that would be appreciated (I'll try to figure out what type of motor this is, hopefully someone here's familiar or it's a standard setup).

Any help or ideas would be much appreciated!

IMG_4490 copyIMG_4499 copy

Original gaskets

New gasket material


Images (4)
  • Leak
  • Leak
  • Original gaskets
  • New gasket material
Videos (1)
Leak video
Last edited by Sean Seena
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Pretty sure the oil pump gets 18 ft. lbs. of torque on the 4 bolts. You SHOULD NOT stick a larger bolt in there, if the holes are stripped you'll have to split the case and basically rebuild the motor, and maybe save the case with time-certs.

Usually, oil pumps have studs in there and sealing nuts on the cover. And you MUST use a thin paper gasket, if the gasket is too thick you'll lose oil pressure.

Buy a 66-69 VW Beetle service manual by Bentley, it will serve you well.

You have a universal/type3 case. The two-bolt flange is not a big deal to seal, use whatever method makes it seal.

@Alan Merklin & @DannyP thanks for your guidance, I was able to know where to direct my research efforts.  

Danny, we went from 8m-something to 10m-1.25 threading, are the tolerances in there so tight that this has caused an issue?  If I'm understanding your point correctly, then we could expect oil leak from the bolt hole?  I'll check if there is any.  If so, instead of a time-sert, what about teflon around the bolt threads?  And/or a gasket for the bolt head?  

Also, I'm curious to know how pressure is lost without a thin gasket, that's interesting.  Something to do with requiring very rigid space?  Or the gears need to turn right up against the cover plate?

I'm going to attempt performing this in a limited garage (think basically apartment garage, it's private but with limited tools/capability).  So I'm going to try to think ahead as much as possible to avoid any surprises.  Any help with these questions would be very appreciated:

Is this the tool you refer to?  Seems like these are generally all the same.  Ps in one of the videos I watched the T head that grabs the oil pump bent and broke!  Hopefully that doesn't happen here:

Then, I think this is the outer gasket? (oil pump to cover plate interface).  I think it's clear these are all the same product #:

Inner gasket? (oil pump to engine case interface):

Lastly, do you recommend any particular gasket sealant and locktite for the screws?  I saw people using different types in youtube videos.

Sean, the thin paper gasket under the oil pump and under the oil pump cover will usually seal any leaks where the bolts(studs) are. Stock cases have studs there FYI, not bolts. The washer and nut on the outside cover can be sealed by a smear of oil-proof Permatex silicone.

I didn't think there was enough room in the oil pump for a 10mm stud or bolt, that's why I suggested a Time-cert.

And yes, you need a thin paper gasket because a thicker gasket will allow pressure to bleed past the ends of the gears.

In order to pull an oil pump, it is usually necessary to loosen the two case studs, one above and one below the oil pump. That should allow the puller to get the pump out without destroying the pump or the puller. Sometimes, when using a puller, you put tension on it, then smack it with a hammer. Sometimes, this jars the pulled object loose. But not every time, some really won't come out without splitting the case.

Get that Bentley manual, there is a ton of information and pictures to help you. Plus thread sizes, torque and wear specs........

"Also, I'm curious to know how pressure is lost without a thin gasket, that's interesting."

An oil pump works by squishing oil between the cogs of the two gears. If you create a gap on the top and bottom, the oil can squish into there instead of your oil passages.

Think trying to drink through a straw with your mouth open.

"Lastly, do you recommend any particular gasket sealant and locktite for the screws?"  

I'll defer to Danny and others with more engine building experience than I, but personally I never do anything other than soaking paper gaskets in oil or a thin coat of grease prior to installing them. Honestly, more to keep them in place than anything else.

Last edited by dlearl476

@DannyP @dlearl476 Ahhh, makes sense now.  So the oil pump gears are sandwiched tightly, and I've now spread the panini bread apart.  So now the salami oil isn't compressed.  I think I'm getting hungry.

I'm now considering having a shop do the work (I finally got around to asking for SoCal shop recommendations here which I meant to do anyway), which is odd because I think I now have a pretty solid understanding of exactly what to do.  And by all indications I can perform it, I'm just concerned about the 1-3 unforeseen things that always unexpectedly go wrong!  And in this garage, I'd be dead in the water.  It would be hard to even get it towed because of the small clearances/bends of this garage area!  

It's a little frustrating because I can do it (and put the saved $$$ toward some other part of the car), but this is probably the wise decision.  It'll depend on what shops I can find nearby and if the cost isn't unconscionable.  If so, at least I have a way better understanding of this region of my car and the rest would just be going through the motions.  That, and I know exactly what the mechanic is dealing with...

@DannyP @Alan Merklin @dlearl476, thank you for all your help

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