Stripped screw on water pump mounting bolt

[mclaveau]

Hi,

I changed the two lip seals on my Oberdorfer water pump because I had an important water leek. I put the pump back in place and started the engine. Everything looked good so far, no more leak. I let the engine run for 10 minutes and noticed that there was an oil leak that seemed to come through the bottom bolt on the water pump... the one that is hard to reach.



I gave it 1/2 a turn, still leaking... another 1/2 a turn... and so on, to notice that the bolt is always free turning. The threads are probably stripped. I tried to remove it and it's impossible. Tried to unscrew while pulling on the pump at the bolt location, using a flat head screw driver... now I feel I'm in big trouble. Any body has an idea ?

[tenders]

Try applying a crowbar to the pump, putting outward pressure on the bolt as you spin it with the socket. You may need a deep socket to be able to effectively grab the bolt while doing this.

Once you have it out, I'm afraid I don't have experience with these myself but I believe a Helicoil will best solve the problem.

[BunnyPlanet169]

And...

As Tenders says, but you may find the process more controlled if you put the other bolt back in to keep the pump from flopping around, keeping the mating surfaces more or less parallel.

In fact, it's been my experience (on other assemblies) that with a more controlled prying perpendicular to the flange, the bolt may pull out without twisting. That said, always try unscrewing first!

Keep the force applied, and the fulcrum, close to the bad bolt and the other bolt should be fine assuming it's more or less fully threaded. Use a longer bolt in the upper hole as required, but once it starts pulling out, it should be easy.

Helicoils are wonderful, assuming you have room to do the drilling and tapping. Don't allow chips into the engine, and be careful to remove the tang of the helicoil with a pair of skinny needle nose pliers.

When you're done - consider purchasing the long head bolt from MMI - simply wonderful! http://www.moyermarine.com/cgi-bin/s...key=CSOB_10_89

[JOHN COOKSON]

And........Part II

A minor point: If you can use a piece of wood as a lever so you don't ding up the flat surfaces.

TRUE GRIT

[Carl-T705]

This is horrible... your vessel is doomed... No only kidding, the above mentioned will get your bolt removed. What you can also try is loosely bolting the pump back on, then get a 7/16 wrench and slip it over the threaded portion of the bolt you are trying to remove, then applying pressure to force the bolt out, while you turn 9/16 wrench to remove the bolt. If you don't want to do the drill and helicoil deal right now , you can try picking up a metric threaded bolt, grade 8 and with the pump removed, thread this bolt into the hole that is stripped, go slowly and remove the bolt to clean the threads of the removed material. This will generally cut new threads to secure the bolt. Make sure that you don't confuse the two different bolts you are now using and put them in the wrong hole on assembly. A metric tap would help here if one is available.

[mclaveau]

Thank's to all of you but...

I tried to pull it out while using a piece of wood, then a crowbar as a lever, had someone to give me a hand... but it won't come out.

The bolt is so damaged now, half way in, half way out, I can turn it easily at hand.

This morning, I will try calling a mecano.

Martin, from Magdalen Islands.

[Carl-T705]

It sounds like a helicoil has already been installed improperly and the coil has threaded through the block into the engine case.

[Mo]

Martin,
Get yourself a piece of flat bar about 1/8 to 1/4 inch thick...as thick as will fit in between the pump and the gap you have made with the bolt partially out. Cut a piece out of the bar and allow it to go down on both sides of the bolt. Will attach a pic of what I mean...then pry out and have someone with a rachet as pressure is applied...it should come. Just need to make a tool for it.

[JOHN COOKSON]

Any chance of gripping the head of the bolt with a pair of vice grips and pulling out while twisting?

TRUE GRIT

[domenic]

Hi,

I changed the two lip seals on my Oberdorfer water pump because I had an important water leek. I put the pump back in place and started the engine. Everything looked good so far, no more leak. I let the engine run for 10 minutes and noticed that there was an oil leak that seemed to come through the bottom bolt on the water pump... the one that is hard to reach.



I gave it 1/2 a turn, still leaking... another 1/2 a turn... and so on, to notice that the bolt is always free turning. The threads are probably stripped. I tried to remove it and it's impossible. Tried to unscrew while pulling on the pump at the bolt location, using a flat head screw driver... now I feel I'm in big trouble. Any body has an idea ?

It's no big deal. You can get it out. If the bolt will twist, it will come out. I drilled seven inches into my lead keel. Broke my own rule, and drilled at high speed. That melted the lead around the drill bit. I twisted the drill bit 1/16th at a time with a pipe wrench until it moved...then just pulled it out.
Don't worry about the threads, You can drill a size larger hole, and re-thread.

Golden Rule: If you can be broken it, it can be fixed.

[mclaveau]

Pump reinstalled but still Oil leak ??

Thank's to all of you. I could finally take it out using a crowbar to pry out the bolt while turning it with a box; we only had to be 2 !

To put back the pump, I drilled the whole 1/16 bigger and made new threads. I reinstalled the pump with a new gasket and some silicone gasket on both surface and around the bolts. I'm now certain that the pump is solid, aligned and not leaking any water or oil.

BUT !!! I still can see some oil leaking from underneath the pump, as it shows on the picture:


Any body has an idea about that ?

[Mo]

I find that if I use silicone as a gasket I put the bolts hand tight for a couple of hours then go back and torque them. Might be you squeezed all the gasket material out of there.

Might look at ordering up a new one from Ken.

[tenders]

This happened to me too after I replaced the lip seals. No idea if it was because of a poor alignment of the lip seal, something worn on the shaft, or something leaking around the bolts or gasket.

I put up with it for a few seasons and ended up replacing the pump. If I had to do it again I'd try a little harder to reseal the bolts.

The basic problem is that the individual pump components are kind of expensive - the tradeoff is expensive parts that take some time to replace and MIGHT solve the problem, but might not, vs an expensive pump that will DEFINITELY solve the problem.

[StephenGwyn]

This was a while ago, but I find myself with a similarly stripped hole. Can you describe in a bit more detail how you did that? There is not a lot of room back there for a drill and a tap handle.

To put back the pump, I drilled the whole 1/16 bigger and made new threads. I reinstalled the pump with a new gasket and some silicone gasket on both surface and around the bolts. I'm now certain that the pump is solid, aligned and not leaking any water or oil.

[Al Schober]

Suspect you may be using a lock washer there - DON'T. Just a plain flat washer, permatex both sides. Ditto for the lower bolts in the transmission aft flange.
edit: Might be a good place for a stud?