New Waterpump Leaks

[Laker]

I ordered a cooling system kit that had a new thermostate, alum thermostate housing, waterpump, hoses and belts and radiator. I had a leaking radiator so I thought when eveything was out it would be a good time for some preventive maintance. My new waterpump is now leaking past the o-ring on the bottom side of pump. Should I try another new o-ring or does bmw use some type of gasket compound to aid in sealing the o-ring? Or maybe I should return pump for another new one?
Thanks for any help

[jkh2828]

did you put some coolant on the o-ring when you installed it? Did you torque it enough? I don't recall the torque to be that high though. That o-ring is pretty thick right? You could try a new one, just a pain to drain everything again.

I didn't have any problems at that spot - my thermostat housing gasket was a b*tch to get to seal - i have a flat aluminum housing (no groove for a gasket).

[Dudesky_E36]

Coating the new o-ring with coolant is pretty important. It not only keeps the rubber from drying out, but also aids in the installation. If you didn't do this, you may have pinched the o-ring, creating a tiny gap. Or the o-ring may just be defective. Either way, you'll have to back out the water pump to see what's going on in there. You did use a new o-ring right? (just checking). And don't use any type of gasket compound. If you do, you'll strip the M6 bolt holes trying to get the pump off in the future. A properly working o-ring is more than sufficient to create the seal.

[Laker]

I put some lithium grease on the o-ring to help with the seal, that was according to my haynes manuel. It still leaked so I returned the pump, should have new one installed by tomorrow. keeping my fingers crossed this one doesn't leak!

[theruss1an1]

Now that it is not a dry rubber o-ring in there it should stop leaking.

-Serge