Fresh Water Pump Gasket Failure

[Gline]

About 2 years ago I replaced the fresh water pump (coolant circulator) on my Universal 5432. I went with a new Kubota pump and provided paper gasket, from Kumar Bros. I used Permatex 22071 Water Pump and Thermostat Housing gasket maker. Worked great and pretty easy job. After about 12 months I noticed a little coolant leak, the seal between the two surfaces was failing. After 2 years I decided it was time to do it over again as the leak was significant.

I removed the pump yesterday and noticed the paper gasket was wet and mushy.

Did I do something wrong? Is there a better gasket or sealant?

I'm planning to clean the surfaces and repeat exactly what I did last time, but this seems crazy as it did not last.

 

[Christian Williams]

Apparently the surfaces are not mating perfectly. Perhaps a sealant like Permatex could be applied with the gasket.

You would know if the bolts loosened, which it seems they didn't. Doubt you did anything wrong, or at least you did it as I would have.

 

[peaman]

It seems some assemblies are more sensitive to specified torque for optimum sealing. Service manuals usually specify the recommended torque for fasteners. A torque wrench can be useful, but for most applications, a reasonable estimate will work. Since torque specs are expressed in units of pressure applied at a distance, if you can estimate how much pressure you apply to a wrench and at what distance that pressure is applied, you can estimate the torque.

Specified units:
foot-pounds, or inch-pounds, or inch-ounce are fairly self-explanatory
lbf and ozf are "pounds force" and "ounce force" respectively, so the "f" can be ignored
SI or metric unit of N-m x 8.85 results in ft-lb

 

[Gline]

Turns out the screw holes on the aftermarket water pump didn't perfectly align with the bolts, so it could not become flush and I wasn't getting a good seal. After a little work with my Dremel, the pump can now sit fully flush. Hopefully others who buy an aftermarket pump can learn from my mistake and dry fit the pump first! Oops