[David Jones]

I was wandering through the pull-a-part Saturday AM and found a mid 70's fullsize Pontiac with a 400 still under the hood, with no radiator. I have a 73 455 shortblock at home but need various parts, one of which is the timing cover. Bingo. Pull-a-Part gets $6.50 for an aluminum timing cover. I took the water pump/fan/timing cover off as a unit and then separated the water pump and fan from the timing cover while I was sitting on the gravel in the shade. That's when I discovered the broken water pump bolt. About 1/4-3/8" of bolt is standing proud of the timing cover, head broken off. I've been soaking it in PB Blaster since I got home and have also tried heating it. You can lock a pair of Vice-Grips on it an turn until they spin metal off the bolt and it won't budge.

Is there a decent way to remove a broken metal bolt from an aluminum part?

[sixtee8gto]

Might have to drill it out.

[oakster]

I had one of the bolts break that goes thru the cover and into the block on a '69 I was taking apart. I had to put a lot of heat on it to get it to come loose.

I'd let it sit for a while and just keep heating it up. At least you can get a vice grips on the top of the bolt.

Drilling it out is always the option of last resort

[OINK 1]

Place GRADE 8 nut on busted bolt, Use arc welder to attach, this will really heat up the bolt and make it loose. Weld on, wait 10 seconds to cool,click on vise grips. Go for it.

Pontiac Gregg

[David Jones]

So removing a broken bolt in aluminum is about the same as one in iron. Heat-soak etc. If I end up drilling it out I think I'll come up from the bottom.

[BVR421]

Originally Posted by OINK 1

Place GRADE 8 nut on busted bolt, Use arc welder to attach, this will really heat up the bolt and make it loose. Weld on, wait 10 seconds to cool,click on vise grips. Go for it.

Pontiac Gregg

ditto, welding on a nut does two things, gives a socket a place and the heat of the welding breaks loose the corrosion and rust on the threads. By the time you put away the welder, the bolt will nearly come out with your fingers.

[fbody_mike]

I gotta try that welding trick next time. I wonder if a mig welder would have enough heat to do the job.

I have used ammonia on aluminum parts that were stuck in steel. Takes a little while but it has worked. I just keep spraying ammonia on the aluminum where it meets the steel. It works wonders on stuck aluminum bicycle parts on chromoly steel frames.

[GTOGreg]

Yep, heat it up

[David Jones]

No welder...........I'll just have to continue with the torch and the PB Blaster.

[scott cedergren]

I have done it with a mig welder works great. Find a nut that slips over the stud snugly and go to an exhaust shop and see if they will put a small weld on, I would think they would do it for free or close to it. Good luck those can be a pain in the a$$

[judgert]

If you have to drill it try to use a drill press so that it is straight, then just keep going up in drill bit sizes little by little till you get to the threads and use a pick to dig out the pieces. When your done use a tap to straighten the threads.

[scott cedergren]

when it comes to drilling it out when done put a heli coil in it. The long term is that it will work better and last longer.

[dmac]

Is this one of the threaded holes or one of the holes that goes through the cover for the bolt to attach to the block? If you can attack from the back side, you could try pressing the broken bolt out, or at least try tapping on it as the PB works into it. And just a question but wouldn't heating the bolt make it expand and be tighter? I would try heating the cover around the bolt while tapping on the bolt, expanding the aluminum around the bolt