Please Help ! Is it standard to replace water pump seal when putting in new water pump in 1996 Impala SS. My mechanic replaced water pump and now leaking oil. Did he make mistake?
Water pumps should not leak oil. The seal is for coolant, not oil. The oil seal is in the timing cover, and that seal is not disturbed on a typical water pump job. Sounds coincidental to me, which is commonplace on a 17 year old car.
Well, if you didn’t have the oil leak before and it started immediately with the water pump replacement there’s a chance that replacing the water pump caused the leak.
The water pump is operated by the timing chain, the two are connected by a shaft that comes out of the timing cover and often times when removing the water pump the shaft that drives it will come out of the timing cover. If your mechanic is not careful or unaware of this setup it’s possible to damage the oil seal around this shaft. The bad news is that if this is in fact what’s leaking you will be doing the whole job over again.
Possibly more. Don’t drive the car until you have this resolved. Oil leaking from that seal may possibly contaminate the distributor, which is located behind and underneath the water pump. Excessive oil can damage the optical sensors in these distributors and will cost several hundred dollars to replace.
Agree with @asemaster. The water pump setup on the SS is not your typical variety. Why GM decided to run the pump with a shaft instead of the highly reliable belt/pulley system is beyond me.