16 RE: Oil Leak from oil pump hole Tue Jul 13, 2010 8:36 am
Dennis
Platinum member
The reason for the metal to metal joint and not a gasket is because the oil pump is a gear pump, which relies on minimal end clearances for efficiency. So use of a gasket would cause that efficiency to be compromised, and in a worst case scenario, if some one was to make a gasket which was too thick the the result would be very low oil pressure and reduced flow.
Also, the metal joint assures perfect alignment with the drive, which in this case is from the end of the output shaft.
The reason for leaks when using silicone (sometimes) is because the oil pump internal pressure could be as much as 70 PSI (4.8 Bar) when the engine is cold, so there is some serious pressure acting on the case to pump joint.
Hope this helps to understand the reason for attention to detail when assembling the pump back onto the engine block.
Spend time getting everything clean, do not touch the joint faces with a file as any damage will cause a leak.
Also, the metal joint assures perfect alignment with the drive, which in this case is from the end of the output shaft.
The reason for leaks when using silicone (sometimes) is because the oil pump internal pressure could be as much as 70 PSI (4.8 Bar) when the engine is cold, so there is some serious pressure acting on the case to pump joint.
Hope this helps to understand the reason for attention to detail when assembling the pump back onto the engine block.
Spend time getting everything clean, do not touch the joint faces with a file as any damage will cause a leak.