Pan leak won’t seal

[Sb_750]

Hello I have a 77 r75 and I can’t get the oil pan to stop Leaking. First I put a silicon gasket did not seal
Then I used rtv and made sure the surface was clean.
Did not seal. Then I bout the normal gasket and it sealed for a week then when I took it on its first longer ride it started leaking again. I’m lost on how to fix this could the pan be warped? When I tightend it I went in a cross pattern and torqued it to spec. Thank you

[Kurt in S.A.]

I believe that the threaded holes that go into the block are actually through holes, so oil can work down the threads. You should try some non-hardening thread sealant, like Hylomar or Permatex Ultra Gray.

Kurt

[Rob Frankham]

Oil leaks from the sump joint are rare, how sure are you that the oil is coming from the sump/block joint? There are a number of places where oil can come from and appear around this joint... notably the push rod tube rubbers, the oil pressure switch and the timing cover joint (especially where it meets the sump joint).

Is it in one area only or is it generally around the whole joint?

It's woirth checking that the sump isn't warped by laying it on a sheet of glass but, really, RTV should effect a seal even if there is quite a bit of warpage.

Rob

[Sb_750]

I am pretty sure that’s where it’s coming from. I see the oil start at the flange in the back right corner.

[Rob Frankham]

OK, then I would think you need to be looking for damage in that area. If RTV hasn't effected a cure, you need to face the possibility that there is damage to either the sump casting or the block in that area. Not a nice thought but cracks and/or porous castings aren't unknown.

Rob

[jackonz]

I had the same issue and it was leaking from the crankshaft rear main oil seal, clean everything off and let it dry, then run the motor for a short ride and look for leaks, use talcum powder and it will stick to where the oil is, you will need to clean the area blow the gear box on the ledge where the rear engine mount pass through the frame, I used degreaser and a water blaster.

You may find as in my case you have more than one leak.