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Broken Mounting bolt on Oil Pump


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Hi everyone,

 

I just had a quick question. I have a 96 legacy 2.5 and am changing the front crank seal on the oil pump. When I was reinstalling the oil pump, I accidentally snapped the upper left mounting bolt...i was just curious as to what I can do to insure that the oil pump will seal up properly without the mounting bolt...(the nub is stuck in the body of the engine, can't remove it)? Can I just seal the hole up with a bunch of Ultra grey? Any ideas?

 

Any help would be greatly appreciated...thanks so much.

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I’ve looked over the manual and color photos of the pump, and it looks like the high pressure side is the o-ring port, and the suction side is the area between the back of the pump and the engine block, but I can’t be sure. For the most part, it doesn’t really matter, as in one case, a bad seal will allow air in leakage, and reduced oil flow with possibly dry startups. In the other case, pressure against the back of the pump will tend to split the two from one another creating an external oil leak path. I do not think I would want to compromise on clamping force in either case, but the o-ring is at the bottom, so if in fact that is the high pressure side, a missing bolt at the top would probably be a bit less critical. If the bolt broke during the assembly process, it's was probably due to overtightening, and the bolt should not be bound up in the hole. The bolt should respond well to normal bolt extraction techniques which have been covered here from time to time. If it was mine, I would remove the oil pump and try to extract the old bolt shank, whatever it took. The normal torque for these bolts is only about 5 ft. lbs, so overtightening is not hard. To assemble without the bolt being in place, As a minimum, the now vacant hole in the pump body will need to be threaded and a bolt installed, or a solid metal plug press fit into the hole, this would seal any leak path through the empty hole, and should stand up to pressure.

 

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I say it really does need to be fixed. If the darn thing leaks then you have to take it all back apart AGAIN! Take a pair of small vice grips and see if you can turn the nub out. Take care not to break off the nub. Then it gets much uglier. If that doesn't work, check prvious postings for other tips. Last resort is drilling out the bolt with a bolt extraction bit. Follow directions on box closely. A keyless chuck drill does not work well for this purpose. I always have to barrow a keyed chuck drill when I run across this. good luck!

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rent or borrow a right angle drill and drill out the old bolt. don't use a bolt extractor, they suck and are a pain if they shear off. use a left handed drill bit. might have to saw or break the drill bit to shorten it so it and the drill fit.

i've done this before, it is possible and it is the way to fix this.

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Can I just seal the hole up with a bunch of Ultra grey? Any ideas?

 

I would say No Way! Sorry, but I think this is one you have to fix.

 

If there is enough bolt sticking out perhaps you can flatten two sides, grap it with some good vice-grips and back it out (?) If not, then the drill may have to come out...

 

Of course the most important thing is DO NOT SCAR THE MATING SURFACE on the engine side while removing the stud.

 

-Heikki

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If you have any of the old bolt still sticking out, you can try a trick I often use at the bicycle shop where I work, although it's possible you may need more torque than this: use a dremel-type tool to cut a slot into the old bolt. You can then use a flathead screwdriver in this slot to remove the bolt. Of course, you will have to be very careful not to damage the mating surface of the engine when cutting the slot into the bolt.

 

Never tried it on a car, but it's an idea.

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rent or borrow a right angle drill and drill out the old bolt. don't use a bolt extractor, they suck and are a pain if they shear off. use a left handed drill bit. might have to saw or break the drill bit to shorten it so it and the drill fit.

i've done this before, it is possible and it is the way to fix this.

I totally agree with gg. According to your post, the bolt broke off while reinstalling it as opposed to breaking it upon removal. It is not rusted/gunked in place. A simple left-twist drill bit will probably spin it right out as soon as the flutes bite into the bolt.

 

Its your engine's lubrication system. Don't gamble with it; do it right.

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