Water Pump Holes Stripped HELP!!

[MrQ]

During my vacation my water pump decided to go awol and dump all its coolant. I decided to do the water pump replacement on the vacation and stripped out two of the screw holes for the water pump. Apparently the old water pump had unloosened most of its bolts over time and stripped out the holes. We just made it worse trying to retap it. It never held, but we were able to get the truck home.

It is now sitting at a mechanics shop with a $1377 repair quote attached. They say the timing chain cover is damaged and they have to pull the whole front of the engine off to fix it.

I am stuck without a vehicle and no way to pay such a bill. HELP!!

 

[nitro71]

Don't panic to fast Mr Q! I'm not an expert on fixing bolt holes as I've not messed to many of them up yet but there are ways to fix them. Helicoils come to mind. Probably have to yank the radiator to get enough room to drill them out. You might be able to weld studs into the stripped holes also. then use a nut to attach your water pump. I'm sure others will have some ideas also.

 

[MrQ]

I have already thought of heliocoils but my electric drill is too big to get in there with the drill bit.

 

[nitro71]

Even with the radiator gone? Might be able to get a 90 degree drill in there.

 

[TedJ]

90 degree drill should fit in there with the rad out, (I'd remove it just to avoid damaging it even if it does fit otherwise) you might have to put the bit in the hole and then put the drill on it, but it will get in there. You could probably rent one of those huge milwaukee right angle drills that electricians and plumbers use to put holes in framing with from a local rental place and use that. Just wear gloves and use the aux handle, and keep your fingers out of any pinch areas. Those things generate absurd torque.

This is all saying that those holes have enough metal left to be drilled out and then tapped oversize. I'm not sure exactly what is going on there, I've never taken a 4.0 water pump off. Also make sure you don't drill too deep...

 

[Hitchhikingmike]

Oh no! Has JBweld come to mind? They advertise people using the stuff to fix cracked engine blocks. Can you attach a picture?

 

[Mbrooks420]

What was the factory thread size? What size did you try to tap it to? How many stripped holes? They make long tap drills so pulling the rad, and using a super long bit might work. I'd forget about the helicoils. A Timesert would be much better for this, granted you could properly countersink the holes, or you could use the special timeserts that do not have the flange, and get cemented in. I'd cement them in regardless, tho.

 

[MrQ]

What was the factory thread size? What size did you try to tap it to? How many stripped holes? They make long tap drills so pulling the rad, and using a super long bit might work. I'd forget about the helicoils. A Timesert would be much better for this, granted you could properly countersink the holes, or you could use the special timeserts that do not have the flange, and get cemented in. I'd cement them in regardless, tho.

Factory thread size is M6x1.

2 stripped holes trying to tap to original size. Then went to M7x1 and then M8x1.25 when the previous ones wouldn't hold.

 

[Hitchhikingmike]

I remember reading about a guy online whom in the process of rebuilding his 7.3L powerstroke, either broke off a corner or broke off part of the threads to a bolt on his front engine covers. He was able to successfulyy repair and use the same engine cover through the wise application of JB weld. I think most all engine covers are aluminum. I wonder if you could use some quick sealing JB weld and just put a bunch of that stuff in the bolt holes and just hold in the bolts as it sets. It takes about 20 minutes to set good. Of course you would have to keep the proper pressure on the bolts so the water pump seals up tightly.

I know there MUST be a way we can solve this.....

....thinking..

 

[MrQ]

I have been trying to track down a local retailer of timeserts, but no joy. The one deal with JB weld is that it if I have to take that pump off again it could cause issues.

 

[Hitchhikingmike]

I have been trying to track down a local retailer of timeserts, but no joy. The one deal with JB weld is that it if I have to take that pump off again it could cause issues.

yeah, I don't think you could if you tried anyway.

I wouldn't really worry about that at this point. The pumps usually last 70k + miles, so it would last you several years to say the least. And by that time it would probably be the least of your worries, as the engine would probably require a lot more major work like rebuilding the heads and timing chains before you ever got to the point of replacing the pump again. And then at that point it would be pie to replace the front cover for a different one.

 

[Mbrooks420]

Were you just retapping the stripped holes without any drilling?

 

[MrQ]

No we tried drilling, but it didn't help. At first we were just trying to straighten out the threads, but later on we tried drilling.

 

[Mbrooks420]

Whatever you do, do NOT try and tap it to 9mm. Next logical size would be a 3/8 16. Being tapped to an 8mm now a 7mm timesert kit would be the best option. If there was enough material I'd get the special 8mm core kit and epoxy it in. JB weld won't work, there's no way to hold the pump tight enough. Are you using a normal style tap wrench? Any ideas as to why the threads are failing?

 

[MrQ]

Any ideas as to why the threads are failing?

Other than the fact that the metal I am tapping is aluminum?

 

[nitro71]

Maybe you could JB Weld a stud in the hole? Probably work better than trying to weld a steel bolt onto aluminum. I don't think JB welding a bolt in will work as you wouldn't be able to tighten it.

 

[MrQ]

Got the water pump out again in half an hour (didn't have to pull the fan). I'm getting good at this...

Apparently the RTV held. It is just those two bolts that kept it from sealing completely. I was worried that something else might have gone wrong.

BTW, anybody who replaces a water pump needs to recheck the bolts after you drive for a little bit. They might need to be re-tightened again.

 

[Mbrooks420]

If you have to do this again I would hand drill the holes out, and used WD-40 for the tap lube. Are you using a bottoming tap?

 

[MrQ]

I think I am going to have to pull the condenser to get to the water pump. I guess I will have to fix the a/c at a later date.

 

[Hitchhikingmike]

I think I am going to have to pull the condenser to get to the water pump. I guess I will have to fix the a/c at a later date.

Just remember to plug the lines when you do so. Try and find some good rubber plugs. You want to keep as much moisture out of the lines as possible. Also help prevent rust and any foreign objects finding their ways inside.