86 740 water pump - paper gasket vs permatex

e777 · Post by **e777** » 21 Jan 2012, 23:18

I have refitted my water pump twice only to find coolant slowly dribbling out from the under side of it. Both times I have used the standard paper gasket. I am thinking I will try permatex in the hope of really getting that thing to stay on (in addition to using brand new bolts and nuts next time). Any reason why permatex would be a bad idea? Or any pointers on using permatex for this application?

Thanks,

Eric
86 740 235K mi.

Post by **writer100** » 23 Jan 2012, 09:44

I've used permatex in the past with success. Follow the instructions.

Also, I believe on your water pump there is a rubber gasket at the top. This is a pressure fit against the head, and must be held under pressure until the pump is torqued down. It is helpful to have another set of hands for this.

Good luck.

Post by **billofdurham** » 23 Jan 2012, 11:50

I haven't used Permatex but I am a firm believer in using a gasket sealant when fitting water pumps. On two occasions when I didn't use a sealant they leaked.

The sealing ring on the top does need to be held firmly in place so how quickly can you grow two more hands?

Bill.

e777 · Post by **e777** » 24 Jan 2012, 08:37

Thanks for the information, writer100 and Bill. Yes, it is a pain to get that upper seal snugly fitted!

Post by **fazool** » 24 Jan 2012, 15:00

Make sure your surfaces scraped/sanded clean. Paper gaskets are junk but they work because they are cheap and easy to assemble on a new motor (where everything is flat and smooth and clean.

Frankly, I've always put a bead of permatex, then the paper gasket, then another bead of permatex.

Sounds stupid but I've always had good luck.

e777 · Post by **e777** » 25 Jan 2012, 15:06

Thanks, fazool. Given the mating surfaces are difficult to get absolutely flat and clean, permatex definitely makes more sense in this case.

e777 · Post by **e777** » 15 Mar 2012, 07:39

Fazool,

I followed your advice and the pump is totally solid and leak-proof. I laid a bead of permatex on the pump edge, where the gasket sits. I pressed the gasket onto the pump and then laid a bead onto the side of the gasket that mates with the engine block, and fit the pump to the block. No leaks after weeks of use! Thanks a million.

Eric
86 740 wagon
90 740 wagon
91 240 wagon

Post by **billofdurham** » 15 Mar 2012, 13:47

Good job. Thank you for the update.

Bill.