Water Pump Advice

[benji808]

Replaced water pump and fan clutch today. Car will be dry-docked for a week or so while the radiator gets repaired so I figured, "might as well." Overall the job went smoothly...everything was pretty easy to access, and overall made for a relaxing Saturday afternoon.

Two issues/questions:

1) I was very careful with the bolts going into the block - liberal use of PB blaster, and torque wrench for re-installing. However, there is one bolt that won't torque down for the reinstall. It goes into the hole and screws in, but then just spins when it should get tight. I suspect that whoever worked on it previously (I don't think the pump is original) stripped something, but what I am not sure. I did try a different bolt in the hole, but it didn't help, so the issue is likely in the block.
Can y'all educate on what's going on behind that front engine cover, and what good options might be? Can I pull the cover and fix something? Use helicoil?  Alternately, I've considered just leaving it to see if it leaks...I'm assuming it's been like that since the last person worked on it and I haven't noticed leaks...maybe having everything else torqued properly is enough... picture of the bolt I'm talking about is circled red in the attached picture.

2) What are your opinions on gasket only vs gasket+sealant. The factory manual said just gasket, with sealant on the 4 smaller bolts, so that's what I did...the previous person went to town on the sealant/liquid gasket so it took me a while to scrape it all off. My general viewpoint is the gasket should do it's job, and so I don't use uncalled for sealant, but interested in others' perspectives.

Thank you!

[Big Fins]

That screw is one of the dreaded 4 screws that can't be cranked down. It has to be torqued in inch pounds. The real cure comes with pulling the front cover and tack welding 1/4-20 nuts to the inside of the cover. And all 4 do require a sealant per the factory service manual.

[benji808]

Right- the other 3 torqued to the factory inch/lb spec, but this one won't. What stripped? Threads in the engine cover itself? Is it likely to leak with just that one not torqued?

[Big Fins]

Yes. Stripped. The threads are actually part of the front cover. Whether or not it leaks is entirely dependent on the gasket used and the sealer. Mount it, pressurize it (16 psi max) and see, is the best I can offer.

[benji808]

Got it - that makes sense. Thank you for the insight!

[Big Fins]

I'll admit that in the years I bent a wrench, I came across a few that were stripped. We loaded them up with 'gasket maker', then hoped when it cured. That was a piss poor design. Just like the fuel pump being right under the P/S pump.

Try it, fill the system with water so there is no real waste except if you are in Kalifornia, and see if it leaks. Personally, I'm wagering that it doesn't.

["Cadillac Kid" Greg Surfas 15364]

Benjamin,
If all the other bolts are spec tight I might suggest you try and get a Metric bolt, just slightly bigger than the 1/4-20 that i stripped (M-8-1.25) and see if you can get that to get a grip on the timing cover.
Greg Surfas

[benji808]

Thanks for the thoughts! Greg- love the metric idea, unfortunately I can't seem to find a way to thread a M8 through the water pump- opening is too narrow.

I guess I'll think on it...is there a good way to test for leaks without the radiator on?

If I do pull the front cover...it looks as simple as taking off a few more bolts and the main pulley. Are there any other watch outs?

["Cadillac Kid" Greg Surfas 15364]

Benjamin
you really do not want to pull the front cover. It is a lot of work. I might suggest removing the water pump, drilling out the bolt hole in the water pump where the stripped bolt is and at the same time seeing if you can re thread the stripped hole to the metric size.
Greg Surfas

[benji808]

Thank you- makes sense. I'm having a shop pull the engine in a few weeks for oil pan gasket, rms, and timing chain, so maybe I will leave it and see if it leaks, and can have them get behind it at that time.

[79 Eldorado]

Benjamin,
If they are pulling it to do the oil pan gasket have them weld the nuts on the back of the front cover like someone else mentioned. I've done that for preventive measure before. If you ever do it without doing the oil pan the bottom gasket is a real pain. A friend who was a dealer tech told me his secret was reuse of the original gasket because it's already compressed to the perfect shape.

Back to the front cover threads they basically extrude some of the cover metal back to provide more thread engagement but it's a little sketchy. I grind off the extra material extruded back and I locate the nut using a bolt threaded through the front.

If the front cover is coming off check to see if you have a plastic tooth timing gear. It would be a perfect time to take care of that as well.

Edit: Also be very careful not to break that timing mark when tightening belts. They are very easy to break with a poorly positioned pry bar.

Scott