swooshdave Posted August 9, 2011 Share Posted August 9, 2011 When the bike is running the ATF comes out the primary filler plug (it's vented). I can't figure out how the primary is getting pressurized, I thought that if the crank seals were bad they would suck, not blow. Thoughts? Quote Link to comment Share on other sites More sharing options...
copemech Posted August 9, 2011 Share Posted August 9, 2011 Somewhat recent experience with the Sherco's and the fuels suggeste this could go both ways, so seals are suspect I would think! Quote Link to comment Share on other sites More sharing options...
swooshdave Posted August 9, 2011 Author Share Posted August 9, 2011 Somewhat recent experience with the Sherco's and the fuels suggeste this could go both ways, so seals are suspect I would think! Yeah, I thought that might be the case. Hope a local place has those size seals. Quote Link to comment Share on other sites More sharing options...
toofasttim Posted August 10, 2011 Share Posted August 10, 2011 (edited) Piston goes down = positive pressure in crankcase. Piston goes up = negative pressure in crankcase. Works both ways Dave. P.S. It will pressurise the drive side because it is easier to push air from the crankcase through the seal during a downward stroke of the piston than it is to suck ATF back into the crankcase through the seal during an upward stroke. Edited August 10, 2011 by TooFastTim Quote Link to comment Share on other sites More sharing options...
swooshdave Posted August 20, 2011 Author Share Posted August 20, 2011 New seals worked. Thanks. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.