Leak at oil filter
Thread Starter
Instructor
Joined: Aug 2012
Posts: 109
Likes: 21
From: Dripping Springs Texas
Leak at oil filter
Have had an oil leak following an engine (454) rebuild on my '73 that looked like it was coming from the oil filter. After determining it was not the oil pressure tap plumbing at fault, I tried several different oil filters to see if that was the cause - no change. The leak was very small, a drip, but was persistent. Ran across an article on BB Chevy engine builds that cautioned to check the oil filter adapter bolts to be sure they were not extending above the gasket seat on the block. This appeared to be OK on my engine, but I removed the oil filter adapter any way and in checking the adapter & bolt combination on the bench, found the bolts the engine builder had used to secure the oil filter adapter were large enough (1/2" heads) that they came into contact with the raised portion of the oil filter (all filters that I tried), just inside the oil filter gasket. I replaced the oil filter adapter bolts with some 5/15-18 button head allen screws, secured with some blue locktite and the filter no longer leaks. Found that the OEM bolts have a 7/16" head versus the 1/2" head the engine builder used. A small difference, but a significant impact. Hope this might help anyone who comes across a similar leak issue.
