Oldssupreme

Hey everyone. Any ideas on how to get this bolt out? The bolt head broke off but I have about 3/4" of the bolt to grab on to. I soaked it in mineral oil and used vice grips but they just dented the bolt. It wouldn't move. Thanks !
Chris

joe_padavano

lemoldsnut

Is the head on or off the engine? In or out of the car?

IF off the engine weld a nut to the stud and unscrew it while it is still hot.

If in use heat to get is good and warm and then a very good pair of vice grips

oldcutlass

Lol, I you have access to a torch, heat the area around the bolt and it will turn right out. Do not heat the bolt and do not overheat to the point of melting the metal.

Oldssupreme

Ok. Great. Thanks guys. The heads are on the block. I didn't remove them. I'll try both of your suggestions.
Chris.

Cutty77

If you have a good stud remover you may have better luck than vise grips.

MDchanic

I've had to do this, too. Heat the area all around the screw. You want it VERY hot, but probably not getting to red yet (don't want to crack the cast iron).
You want to use an oxygen-torch (oxy-acetylene, oxy-propane, oxy-MAPP, whatever), not a regular propane torch.

You will find that the exhaust screws screw into their own webs, and most are not blind (depends on the casting, I believe), so you can actually heat the surrounding area pretty well.

- Eric

joe_padavano

Note that four of the five exhaust manifold bolts are in through holes. Only the center bolt is in a blind hole. If this is one of the four, be sure to apply penetrating oil (not mineral oil) to the backside and allow it to penetrate.

Charlie Jones

A trick I learned at an automotive machine shop is to heat the stud and the area around it with an acytelene torch and then apply parrifin (wax) on it .
The hot parrafin penetrates like crazy.

Oldssupreme

Hey thanks so much to all of you. I'll report back To let you know what works.
Chris

Oldssupreme

I only have a propane torch. Does anyone rent these types of acetylene/ oxygen torches???

MDchanic

You may be able to get away with one of the tiny Bernz-O-Matic Oxy-MAPP torches.
I think they're about forty bucks at some hardware stores. The trick would be to concentrate all the heat you can on the metal around the screw. If you use one of those, you do not need to worry about overheating anything.



Also, if you use one of these, you need to have at least 3 bottles of oxygen available - they go fast.

- Eric

Gary's 2 442-S

I just went thru removing the center manifold bolt. It broke off when I tried to remove it and I let it sit in PB Blaster spraying it at least every other day for at least 3 weeks. I first tried using a pair of vise grips which are a very good pair and still could not remove it. I then welded another bolt on it and it twisted off. I then determined that someone had used a bolt other than a grade 8 bolt. i never could understand why anyone would use anything but a grade 8 bolt on manifolds

So my next step was then to drill the bolt/stud out first by using a small drill bit and then the next size and then finally one that was just a little bit smaller than the bolt. it came out and I used a tap to ream it out. Very little damage was done to the threads. I was going to use a Heli Coil but it was unnecessary. I was lucky!

z11375ss

The reason why everyone is saying to heat the head and not the bolt is because the metal on the head will expand releasing the bolt. It wasn't mentioned. Just thought I would. Many things that many here assume are known knowledge are really not. Good luck.

Oldssupreme

Thank you all! Very much appreciated. I'll be working on this next week.

quaddriver

x2 on the stud remover - its a good set of tools to have in the box. 3/4 inch should be enough to grab. vice grips, sadly are really only good enough for extracting details on enemy troop movements (torture reference...)

keep in mind: there is practically no torque SUPPOSED to be used on an exhaust bolt (usually 20-30ft) so its held in by rust and galling. use PB blaster or ATF+dishwashing detergent (trust me)

if its broken off flush, then the fix sucks more, but usually a small hole and a screw type extractor works. I get leery of the welding method on assembled heads - various valves can spot weld themselves to seats on the grounding path....

Oldssupreme

Thanks quad. It's not flush so I'll try your mgic concoction of ATF and dish washing detergent. Any particular brand?

Tedd Thompson

Never heard of ATF and dishwasher liquid.I always used 50%-50% ATF and acetone but what do I know, learn something every day on this site..... Tedd

Oldssupreme

Me too Tedd! I wouldn't be able to do this project without these guys!

quaddriver

sorry I was not back sooner...atf is a wonderful penetrating oil, the dishwashing liquid (very little, not like 50-50) acts as an emulsifier and lets it squeeze in smaller places. I got that one from the ford guys years back...

Oldssupreme

Ok. Im kind of dissapointed that i couldnt try some of the more exciting remedies, but soaking it in boring old WD40 for two nights worked. Now if only that broken valve cover bolt/bit/extrator would come out that easily!
Thanks guys!
Chris

MDchanic

How boring.

- Eric