Check this out...

OEM water pump experienced catastrophic failure at 150,XXX miles.





The screw backed out and the impeller wore a pretty significant gouge into the plate. That's how far the screw was backed out. I removed the other screw and didn't notice any thread lock or thread seal from the factory.

My new OEM Ford water pump has these screws. Should I use a thread lock on these?

Have any of you ever seen this before? Because when I saw it, the first thing I said was, WTF?!?!?!?!?

 

Sure. There's no reason NOT to use LocTite on those screws.

Just do it.

Pop

 

I agree.


filler....

 

Ha!

(more filler)

Pop

 

Was there any play in the shaft? The only time I recall seeing those screws loose was when there was play on the water pump shaft and the vibration loosened the screw.

I do agree with the others though, no reason not to use loctite.

 

I hate it.



More filler yet.

 

Loctite it is. Thanks.

Yes, there is play in the shaft. Coolant literally poured out from the shaft when the truck was parked after I discovered a lake under the truck.

In the first picture, the coolant vane in the lower left is nice and clear and smooth. On my new pump, it's ~3/4 that size because of huge burrs clogging the hole. No damage to clean that up and make it full size, right?

The gasket on the new pump is not blue or oval in cross section as the one pictured. It is black and rectangular in cross section. I've seen mention of an o-ring/gasket lube to use in this application, but when I asked for this at the parts store, they looked at me like I was ****ing idiot. Will Vaseline work for this?

Is RTV required on any flange or mating surface on this? I didn't see any on anything I removed.

I noticed a thread coating on a few of the bolts which fasten the pump to the motor. Is that a sealant, Loctite or anti-seize?

 

The only RVT I would use is to hold the O-ring in the groove so it wouldn't fall out when installing. Make sure the other surface is nice and clean though.

 

The very first thing to do is "chase" all threaded holes and bolts with the appropriate tap or die.

Then, make sure that everything on all mating surfaces is spotlessly clean.

I like to use a VERY light film of Aviation Form-a-Gasket on both surfaces and in the o-ring groove, and I've never had a leak. I also put a light film on the bolt threads. Torque the bolts to only 18 ft/lbs, as the factory value is in error.

Maybe I've been just lucky with the Form-a-Gasket, or maybe it really works well. I dunno'.

I do the same thing on the thermostat housing, too. Place the housing down on the pump body with the gasket and thermostat in position, then push down slightly on the housing while threading the three bolts in by hand. When the bolt heads have all touched the housing surface snugly, begin turning each down, a half-turn each at a time, until tight. That takes the housing down evenly and prevents the gasket from moving out of place. Again, no leaks.

That gasket material works wonders on the plug and hose-fitting threads, too.

Just my two cents. YMMV.........

Pop

 

I thought that technically, you should use a thread restorer and not a tap since a tap is meant to cut new threads, not restore existing ones.

Of course I used a tap and die set for years and years to fix threads and didn't even know there was a difference until someone online pointed it out to me. Of course I had to go out and buy a thread restorer kit, so at least I feel special now.

 

Yes there is a difference. There are thread "chasers" and then regular taps. Regular taps will remove a tiny bit of material making the threads a bit weaker. However taps are what I use to chase threads. But I am not one that just goes and chases all the threads I encounter when doing any motor work. I only chase threads that either I had trouble with getting bolts out, can see rust or corrosion, or are buggered up from some other problem.

 

Actually my preferred method is to use a wire brush type thingy on a drill to clean threads.

 

When I replaced my original water pump around 260k or so....those two screws were very loose. Probably 3 or 4 full turns. The new pump screws got Loctite.

 

I checked the new water pump's #3 Phillips countersunk screws ~5 minutes ago. They weren't even finger tight.

I applied Loctite and tightened the screws down like you would with a #3 Phillips, not like the limp-wrist did in the factory.

I talked to my dad about chasing threads... He said you can chase threads with a tap if you're familiar with the feel of a tap. Dad does it all the time and he doesn't thin the threads or hog it out and cause loose bolts. He never chases threads with a dry tap either, always lubricated. He does the same thing with dies. He's a master machinist with 50 years experience, so I suppose he knows the feel of a tap and die by now. He does use a specific type of tap when chasing threads in blind holes VS thru-holes and went on about the number of flutes.

I have to get out there and mow the yard, then clean up the mating surface on the block with some scotch brite. Thanks for the help.