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Well darn it. Will not be starting the rebuilt engine for the first time today. Got me a coolant leak. As I was pouring in coolant I heard a dripping noise and discovered a pretty steady trickle of coolant running down the drivers side of the engine following the line of the gasket between front cover and front iron. Traced it upwards and seems to be coming from behind the water pump. Searched the forums and see there is a 'gland' on the backside of the water pump that is known to fail and result in the symptoms I am seeing. However, I cant find anything more on the gland and what to do about it.
Questions.
- Replace the water pump, or try to fix/replace the 'gland'? If so, any resources you can point me at? Dont even know what this gland looks like or what it does.
- I also see some dampness around the pump to front iron gasket. Does not seem to be likely to produce what is a pretty good trickle of coolant. Should I assume this is a parallel problem to the gland, and add some Permatex to the gasket when I replace/rebuild the pump? Used Gasgacinch last time.
Top of water pump, alternator removed. Damp patch at gasket between pump and front iron. Below water pump, front cover to front iron showing stream of coolant running from water pump above.
"Gland" is not a thing. There's a small gasket where the water pump housing mounts to the front cover, and then a larger gasket where the actual WP mounts to the WP housing. Assuming you torqued everything down properly, I'm going to guess you didn't install the 2 shims on the left 2 mounting studs. There are 4 long studs that hold the water pump housing (and wp) onto the front cover. You NEED to put the 2 shims ( super-thin washers) on the 2 left-most studs to equal the thickness of the compressed smaller gasket. Otherwise... the WP housing will **** slightly towards the pass. side and cause this leak. I am 99% sure this is what you're seeing.
The shims are cheap from Mazdatrix or Atkins. I also use a thin smear of RTV (or similar) on both sides of both paper gaskets.
PS - I have no idea why Mazda designed it to need these shims (super-thin washers). why not just make the front cover or WP housing slightly thicker at these 2 points?
BINGO! That was exactly it. Pulled off the water pump (pain in the *** as the pulleys on this car overlap so you have to take the pump apart) and sure enough, no shims on the two non-gasket bolts. Checked back on the Haynes manual we are using, and no mention of shims. Gives nice clear torque settings and tightening sequence but totally misses the shims. Haynes also starts the section on the water pump by saying the majority of leaks are gland faliures that then drain through the weep hole in the casing... so sending me in the wrong direction.
Thanks! Literally could not do this without you guys.
Another thing to note when reassembling the water pump and housing is to make sure the water pump housing to front cover gasket is installed in the correct orientation. It may sound ridiculous but it will fit incorrectly and if you're rushing through the job you may not notice its backwards and install the housing and pump. Been there and it did leak. Stupid mistake but I'd rather educate others on the mistake I made so they do not make the same mistake.
BINGO! That was exactly it. Pulled off the water pump (pain in the *** as the pulleys on this car overlap so you have to take the pump apart) and sure enough, no shims on the two non-gasket bolts. Checked back on the Haynes manual we are using, and no mention of shims. Gives nice clear torque settings and tightening sequence but totally misses the shims. Haynes also starts the section on the water pump by saying the majority of leaks are gland faliures that then drain through the weep hole in the casing... so sending me in the wrong direction.
Thanks! Literally could not do this without you guys.
Definitely ordering the factory manual. Learned my lesson on this one. Then again... would I have spotted the need for those shims? Its such an odd design decision, why not just create a little extra thickness in the casting instead? Really would not have been looking for it and would have probably made the same mistake even with a decent manual. Anyhow, will know next time.
Idk, but the "gland" leak they mention is probably the seal around the pump shaft. There is a weep hole where the coolant will drain when the seal fails.
03-16-22, 03:03 PM
