Valid Water Pump Leak Test?

[newman27]

I thought I would post this for open discussion. I have a water pump that is virtually new but leaked on the car apparently from my poor application of gasket sealer so I am redoing today - correctly I hope! I'm paranoid about the pump leaking from the shaft (this one has no weep hole BTW) even though I am 99% certain I was able to isolate the leak to a spot on the gasket. I've devised the leak test pictured here and am interested in opinions on whether or not this test would in fact reveal a pump with a leaky shaft (presumably due to bad bearings). Basically, I have inverted the pump and tilted it back and filled it with water until the water came out the front opening where the radiator hose would be. The cavity is thus full of water. If no water drips down the shaft to the plate where the fan attaches - can I feel fairly confident I have a sound water pump? Or, is pressure and rotation necessary to reveal such a leak (i.e., it has to be on the car and in use to tell)? I really don't want to do this again... Thoughts?

Thanks,

Matt

[jmbinjax]

Pressure would definitely come into play. I'm not aware of a bench test for a waterpump. Maybe a teaspoon of sugar, as it appears to be readily available

[timemachine]

Originally Posted by jmbinjax Pressure would definitely come into play.

Agreed. It's possible you got a bad pump but more likely that the gasket is leaking. I prefer not to use gasket sealer when replacing the pump since a paper gasket is fine for the job if you take your time to remove every last bit of the residue from the timing cover.

Jim

[newman27]

Originally Posted by jmbinjax Pressure would definitely come into play. I'm not aware of a bench test for a waterpump. Maybe a teaspoon of sugar, as it appears to be readily available

Actually, that is full of Starbucks Verona beans . I better that get that thing off the counter before my wife gets home! Thanks for the comments...

Matt

[hrcollinsjr]

Matt as Jim as already mentioned if you'll clean the sealing surfaces the paper gasket should be fine. The FSM rates the cap pressures as 13.2-15.2. I had water pumps that didn't show rear signs of leaking until after you shut the engine down and it built up more pressure because of the heat.

Tip: You may want to only use water until you know it doesn't leak. Then you can drain it anywhere and add coolant when you're sure you have successfully fixed the problem.

Harold

[guyopel]

When you get it back together call me at home I have my pressure tester here and we can check it . I will P.M. you my cell number .
John

[newman27]

Originally Posted by hrcollinsjr ...I had water pumps that didn't show rear signs of leaking until after you shut the engine down and it built up more pressure because of the heat. Tip: You may want to only use water until you know it doesn't leak. Then you can drain it anywhere and add coolant when you're sure you have successfully fixed the problem. Harold

That's what mine was doing - leaking after the car was shut down and sat for a while. Thanks for the idea on using water only - the main thing I hate about this job is the mess the coolant makes when it drips all over the place...

Originally Posted by guyopel When you get it back together call me at home I have my pressure tester here and we can check it . I will P.M. you my cell number . John

Thanks John - everything is cleaned up and prepped for an early Sunday morning install. It all looks good and is clean, I just need a nice secure seal there. I'll give you a call once everything is in place.

Matt

[newman27]

OK, I can confirm that my rigged up test pictured in post #1 above is NOT a valid test. I put that pump back on the car and it leaked from the shaft anyway . I pulled out my spare pump and a new gasket and so far no leaks after a day with a couple test drives taken. BTW, this latest pump is different than any others I have used. I've attached a picture from the Rock Auto website. Notice that the impeller blades are not open but rather enclosed in a solid casting. I also noted that this pump felt "tighter" when turning it by hand and that the shaft where the fan attaches is slightly shorter than the others I have used. My hope is that all this translates into a more robust, fail-proof water pump.

The good news is that at this point I am an expert at water pump removal and replacement. I can have the radiator out of the car, hoses, belts, and the pump removed, and be cleaning the old gasket off the timing cover in about 15 minutes. Not bad for me anyway...

Matt

[RallyBob]

Originally Posted by newman27 BTW, this latest pump is different than any others I have used. I've attached a picture from the Rock Auto website. Notice that the impeller blades are not open but rather enclosed in a solid casting.

That's a cast iron impellor, which is what our Opels came with from the factory. Most of the cheaper aftermarket replacement pumps use a stamped steel impellor which is not as efficient at cooling. I won't use the stamped steel versions in any performance engine...they don't cool as well due to cavitation.

[hrcollinsjr]

Originally Posted by RallyBob That's a cast iron impellor, which is what our Opels came with from the factory.

And they seem to come in two varieties, either w/straight or curved impellors. I may have even seen these two versions in the cheaper stamped steel ones also. Too many water pump installations and not all of them as easy as the Opels. Right Matt?

Harold

[newman27]

Originally Posted by RallyBob That's a cast iron impellor, which is what our Opels came with from the factory. Most of the cheaper aftermarket replacement pumps use a stamped steel impellor which is not as efficient at cooling. I won't use the stamped steel versions in any performance engine...they don't cool as well due to cavitation.

This makes me feel better - thanks!

Originally Posted by hrcollinsjr And they seem to come in two varieties, either w/straight or curved impellors. I may have even seen these two versions in the cheaper stamped steel ones also. Too many water pump installations and not all of them as easy as the Opels. Right Matt? Harold

Right Harold - easy as pie now

Matt