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I know that this is about my car but you guys all always helped me out before.

You see, now I did it. I wanted to change the thermostat on my 41 Plymouth Staff Car P12 and I broke off the nut that holds the housing down. This is a running car and the engine is/was running fine. What made me do this was that I HAD to change all the radiator hoses, dry rot. So I figure that while I am here I may as well replace everything.


SO. What do I do now? How do I get this bolt out?

Thanks

Carmen

Screw Extractor, might be an easy way. Is there a stub showing?
(did you remove the water pump outlet completely)
If there is, try heating it as long as there is enough to grab w/channel locks or vise grips?, Might be able to drill and remove the excess double helix like leftovers, I wouldn't recommend this!
I think I could screw that up myself?

When you say you broke the nut are you saying you broke the housin? I am not familiar with the motor in your vehicle, but I know that some enginse the thermostat housing bolts into the block and the "nut" is a threaded hole in the block. If you broke the housing like a tab that was theaded then you may have a bigger problem requiring some help from a machine shop.

Did you strip the threads and just cant get the bolt to tighten up and hold down? If so you might be able to get a heila coil and replace the threads. I know on M151's it was common for the threads to strip on the exhust manifolds and we would just drill it out and put a nut underneath. Maybe you can do that?

I'm a visual learner so with out seeing it I'm afraid I'm not much help.

You can try heating the stud/bolt to a dull red then hold a candle to it. Let the candle wax run down into the threads, then let it cool down a bit. May have to do it a few times. Use vise grips on the exposed threads if any, otherwise drill the bolt and use the easy-out. Work it back and forth gently til the bolt starts to move. No movement? Heat again, more wax, and patience(this is important. Snap off an easy-out and you WON'T be happy!) I have had good results this way. Kroil (or something similar) will also work in place of the candle wax.

I let it sit for two days with Kroil. It seems to me that the stud is a double treaded bolt. The lower parts screws into the head and the rest of the bolt goes up through the housing which is then held on with a nut. I snap off the nut flush with the housing. I did not attemp to remove the other side. Was going to use some heat but changed my mind. I really screwed this one up big time.


one down cookie


Carmen

Hi Carmen,
So, the stud is broken off flush with the thermostat housing? If that is the case, I would heat the other nut and remove it, then pull the housing. You will then have enough of the stud exposed to get on it with Vise grips, or weld a nut onto the broken stud. The heat from the welding will usually be enough to free it, then turn it out with a wrench.
Thats how I would go about it.
Good luck,
Tim

Heat, wax, then more heat, more wax(or kroil if you prefer) and you should be able to get the other nut off. Then remove the housing and you can get your vise grips on the broken stud. Just work it back and forth easy and use heat as needed. Again, patience is the key....

If you have enough to grip with vise grips, a small pipe wrench might be a better choice because it grips tighter as you pull harder.

If you end up drilling it out, the most important thing is to ensure the drilled hole is centered in the stud. If it's offset much in any direction the extractor will break because it isn't applying pressure evenly around the interior of the hole.
Gary

I agree with Tim. Heat the other nut, Take off the housing. Then heat the broken stud, let it cool some and it should come out. Don't try an easyout on a bolt that twisted off due to rust. It will usually not work. Plus, That was a stud and they are often in pretty tight.
If you end up with it broke off flush with the block there is a way that I use that works better than welding a nut on. I usually can't get the weld to penetrate the bolt well enough before the nut is filled up. So I build up the bolt with weld by using short bursts of weld with a wire feed welder. Really short, half second or so. I keep doing this until I have enough new bolt sticking up to grab with a vicegrip. The heat of doing this also loosens the bolt, making it easier to remove. this works best on cast iron because if you overlap the weld a little it doesn't "stick" to cast iron as well.
Ray

Up Date

Got the other nut off. Heat and soak then more heat. It came off. Done for the day - don't want to push my luck. Will work on the broken bolt tomorrow.

Carmen

Hi Carmen,
Thats great! You are on your way now.
Good luck
Tim

A slight change in advice, yes heat, wax, then heat to the block not the bolt. Metal expands when heated, if you heat the bolt it will expand and tighten in the block, if you heat the block the bolt hole will expand around the bolt.
good luck,
Rich

Great new guys. I got the stud out. Used the heat soak system. I am so happy that I didn't brake the stud in the hold.

Thank you so much for the help just knowing that someone else was feeling the pain like I was really meant a lot.


Thanks Again


Carmen