'89 740 B230F. I am completely stumped. I recently changed out the timing belt from failure due to the cam seal leaking. I changed out all three seals only to have the cam seal start leaking again. Checked the flame trap and assoc. hoses. They were surprisingly clean. Getting good vaccuum and vent to the crankcase. Help.

Is it leaking around the inner diameter or the outer diameter?

I've had a couple of non-OEM seals (both crank shaft and cam shaft) that the outer diameter didn't fit very tight in the casings. I tried an actual Volvo seal (from dealer) which looked somewhat different - black vs red, and was actually a little narrower. Of course it cost me twice as much $ but it was a pretty good fit.

Check the surface on the cam. I rcently had a 234 twincam with the same problem. Turns out the engine had been sitting for a long time and moisture had caused rust on the sealing surface which was too deep to polish away. Had to get another cam.

Nicked the camshaft while removing old seal?....I did this--used crocus cloth to polish light scratches out....Correct seal, i.e., size?....Damaged the seal lips while installing?
I replaced all three seals at 100K....As I recall, I was able to push them all in a tad past the locations of the originals so that the seal lips were riding on virgin surfaces. The old seal may have worn minute grooves in the camshaft....
Hope this helps some,
--
Jim Nau '91 740 130K

I thought I was smart by buying Fram seals. I will go to Volvo and get one. It did go in easier than I thought it should. You guys are great. Thanks for the advice. Hopefully this will do it.
'89 740 auto 182K
'90 740 man 194K 29mpg
lovin' 'em