1993 2WD F150. Was replacing my newphew's water pump. A bolt snapped off in the hole which we didn't realize until trying to get the remaining portion of the bolt back in the hole on reassembly. Woulnd't thread and I looked and the entire threaded portion had broken off when we were removing the bolt. Of course, the water pump leaks. Any suggestions on how to proceed with the re-fix? He made me reassemble the whole thing after we discovered the broken bolt so he could drive it home. It wasn't my fault. Of course, he wants me to help with the repair. Any suggestions would help. Thanks.

 

If the bolt broke off flush with the block, You will have to take everything back off and most likely drill the broken piece and use an easy out. Might spray it with some penetrant and possibly put some heat to it. Nothing worse than breaking off an easy out in a stuck bolt, they're about impossible to drill through.

 

Left-handed drill bits are your friend. WhatEVER you do, don't attempt to force the new one in in an effort to srew the broken one in further to get the seal. Believe it or not, I actually saw a guy try that once - you can imagine the outcome, even after the idiot tried jb weld to fill the crack, LOL. Oh, well, some people just don't listen to common sense.

Left handed drill bits are available almost anywhere, including Sears, The Home Depot, Ace Hardware, etc... get a QUALITY set for the extra money... they pay for themselves in no time.

 

You need to be very careful trying to get this out. The broken bolt is much harder than the engine block and it is very easy to accidentally drill off the side of the bolt and really mess up the bolt hole. This can happen easily, because you are going to be at a bad angle trying to drill. I would actually talk to a machine shop to see if they can do it or if they can give you some suggestions

If you do it yourself, you can try an easy out. But as said before, don't force it, because if you break it off inside, you are in serious trouble. But, hopefully we won't have to deal with that. At least yet.

You will need to center punch the broken bolt first. This will help you to not slip off the side. I think that if you can heat it up somehow there is much more of a chance that this will work whether you are using an easy out or a reverse drill bit. A steel bolt in what is probably an aluminum engine can really be fused together and heat can really work wonders. And fused is problaby the case since it broke in the first place. I am not sure about how to do the heat safely in such a tight area. Maybe someone else will have a suggestion.

 

Thanks everyone. I had a feeling that the easy out was my best bit. The suggestion about the punch in the center of the sheared bolt was something I hadn't thought of when I was dreading the upcoming job. I was worried about sliding off center and ruining the hole threads. Should I retap the hole IF I get the broken section out or should I use a thread insert and a smaller bolt?

 

Hopefully if you get the bolt to unscrew, you can just use the old threads. If you use heat on it this is more likely to happen. I have never used one, but I just found out there is a heat gun that can be used safely to do this job. It looks like a hair dryer, but gernerates much more heat.

 

Well, what happened?

 

Well, my nehew called me yesterday when I returned from a wedding. He was having a friend's father who does machine work or something either as a hobby or vocation take care of the broken bolt. That was what he told me he was doing a week and a half earlier. Apparently the previous weekend, the guy was doing the reverse bit deal on the broken bolt and the threaded part that was seized split or broke up without coming out of the hole. So, they go at it again two days ago(Sat). They took the timing chain cover off and had to go around to the other side of the bolt hole and heat it up and he used vise grips to get it out. I had a hard time envisioning this but that is what my nephew said. He probably got it half right on what happened because he isn't very mechanically inclined. That's why he comes to me for his wrenching. Bottom line, it broke again and they were able to get the parts out without damaging the threads, buttoned it back up with new seals, gaskets, chain, etc and it is performing very well. Thanks for the advice guys.

 

Well, glad it worke dout for you.

An "old guy" trick is to heat the bolt stub with an oxy torch, then pull it away and push ordinary ivory soap against the stub and let it boil into the threads. Candle wax also works. repeat a few times and often this makes reverse drills even easier to use.

Another "old guy" truck is since the block is iron, and the bolt is steel, is to place a non-plated nut over whats left of the bolt, even if its not sticking through. Then fire up your arc or mig welder, and weld (starting in the center) onto the bolt, working your way around the inside of the nut until it fills in, and the nut is tied to the bolt.

let cool, then remove it normall as if the nut is the bolthead.

I had to do that on a pair of 460 heads, I had broken several exhaust studs. See, steel welding wire either from arc welding or mig welding, sticks to the nut and the bolt, but not the cast iron block.

Backed right out. Sometimes it might take two shots to get the nut to stick, but when you get it, you'll be saying to yourself "holy *****, that was too easy".

I dispise reverse drill bits. I've broken enough of them in bolts to be quite unhappy.

Anyway, glad it worked out for ya.

 

I printed out your "old guy" tricks for futrue reference, Frederic. I will see if my nephews "machinist" knows about them also. Thanks.

 

I call them "old guy tricks" humorously, typically because you don't see those kind of techniques in books anymore. Kinda like metal forming with an english wheel, or body work done with lead instead of bondo (thats where the name "lead sled" came from in the 50's... leading was very popular and definately an art in itself).

Anyway, the welded nut trick works extremely well if you clean the head of the broken stud a bit. I used a dremel with a flathead milling cutter, and didn't mangle the threads of the head at all. Chased them with a tap just to be sure.

 

Glad to hear it turned alright. Your problaby glad you missed that one. It sounds like it was a real pain.