Join Date: Dec 2002
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Re: oil leak problem on sbc
The valve covers are the most likely source for a leak. I just learned this lesson again a few weeks ago. I was sure that I had a rear main seal leak, took all the bolts on the oil pan off to replace the seal when I saw oil drops from the corner of the head. It turned out to be a crack in each of the valve cover gaskets and the oil collected at the bellhousing, just like a rear main seal leak. Fortunately, I had not yet broken the seal between the pan and the block so I was able to just put all the bolts back. When you replace a valve cover gasket, make sure that the lips are flat and straight, especially at the bolt holes, and don't overtorque. Rule out all other possibilities before you work on the rear main seal.
To replace the rear main seal, you need to pull the oil pan, loosen all caps so that the crankshaft drops slightly and tap the old seal out with a brass drift.