Oil leaking from crankshaft pulley
 

after putting on a new scat aluminum pulley and installing the engine, oil leaks pretty bad from behind the pulley. i tried reinstalling the old stock pulley but the oil is still coming out at a rate which is upsetting. Ive tried cranking it down tighter than ****, but it still decides it wants to leak. any suggestions on how to stop or at least slow this leak?

how did you take off the old pulley? hopfully it didn't get damaged taking off the pulley.

also what kind of case pressure do you have? could be you have to high a case pressure pushing the oil out.

not sure if these are helpful but good luck :o

i had this problem with my old engine which is why i just built aqnother that i knew was solid.

but it would be interesting to see what it might be.

i took the old pulley off with a pulley puller and it came off easily and smoothly. not sure what kind of case pressure i have but i did just install a new 26mm oil pump. the engine is not old, it has about 7 or 8000 miles on it and i had believed that it was leaking a bit from behind the pulley before this recent exchange of new parts, but after the new parts were installed the oil leak became very noticable. i think i am going to try to use a slip in sand seal and see how that does.

aight peaceeee

I had this same problem years ago on one of my first engine builds. I though that I installed the oil slinger the wrong way but I was very careful during the crank assembly to get it right. Before you go the sand seal, measure the pulley and compare it to a stock one. I found about a .012 to .024 difference between five different pulleys and a stock one. In the end I went to the slip in sand seal hope this helps.

I have seen a couple of folks forget the oil slinger when they build up the cranksaft and oil came out around the pully like mad. Make sure the slinger is installed.

there actually is an oil slinger installed. it doesnt look like it is doing very much though. there is a nice gap between it and the case on the bottom, but maybe there should be i dont know. to install a new one of these you would have to split the case right? i think i will just try a slip in sand seal and see if that helps.

thanks

That would be what I would try first. Make sure you get a matching pulley.
Do you have a breather box and vented valve covers?

yeah, i have a breather box with lines going to the valve covers. once i get the pulley and seal installed ill follow up on how it works.

same thing happened to me a few weeks ago!! the problem with mine was that the air breather HOSE coming off the oil filler that connects under the air filter was kinked; therefore not letting the eng breathe! it had to breathe somewhere so it decided to come out from behind the crank pully as you described. hope this has helped out! let us all know! :cool:

jsut got the pulley. i am supposed to glue the seal to the case right? not glue the seal to the pulley...correct?

I would say so. You don't want to glue it to the pulley.

i put the new pulley and seal on yesterday, ran the engine for a little while and noticed oil had stopped coming out from behind the pulley and now a little bit was finding its way up through the bolt and washer then being flung around and off the pulley. so i sealed it with some gasket maker stuff and let it cure overnight. i also sealed off the tube that was coming down from the oil filler that didnt go anywhere cause i had noticed a little bit of oil leaking from here too. checked the breather box connections and things and took it for a drive today for the first time in a while. checked the engine after the drive and no oil had leaked from the pulley. it is nice. thanks for all the help, i recommend the slip in sand seals to anyone who also has this problem.

good to here :agree:

sounds like some weird preassure happening to push oil out through the crank pulley bolt.

well at least it's fixed :)