Broken Thermostat Housing Bolt. Now What?

[brian]

As you can see, my housing is really at the end-of-life.

how so?

 

[mags]

That's one heck of a stuck bolt. I had a similar situation but my stud actually sheered in the housing. Used an "Easy-Out" to remove it. You just drill into the bolt with one of the included bits, and then use the reverse gripper bit after you have gotten sufficiently deep enough with the standard drill bit. Mine, luckily, came right out. Although in your situation I don't know if the easy out would've worked so efficiently. That bolt is really bad if you can't get it out with heat and some vice grips.

 

[brian]

canned heat isn't really hot enough for this sorta thing. it doesn't get the piece you want to heat hot enough quickly, before the piece you don't want hot, gets hot too.

 

[JohnnyC]

That stinks

 

[HJ45]

Those bolts.

 

[Weber Sarge]

Just fyi - I get parts like that shipped here for repairs . Most times it's repair filling old cast aluminum parts that have been eaten by bad antifreeze or broken fasteners , like thermostat housing necks , bases , water pump castings , ect...
Some jobs are quite time consuming , but for some reason I enjoy it - nice to be able to save rare or nla parts for folks .
You really can't rely on a Mapp torch , it's not a fast enough heat nor concentrated enough .

Sarge

 

[Racer65]

canned heat isn't really hot enough for this sorta thing. it doesn't get the piece you want to heat hot enough quickly, before the piece you don't want hot, gets hot too.

It's hard to tell at which point I might melt the housing. Lesson learned. Welding a nut would've been a safer path.

 

[73FJ40]

Been there done that. I bought my FJ40 in June of 1977. I had all kinds of "PO" issues, of course not discovered until after the fact.

It came to a cold morning in September and I had no heat. Long story short, I opened up the T-Stat housing (of course, shearing off the outboard bolt) and discovered no T-Stat. Being young and broke and not even thinking about going to Toyota for a part, I drilled the remaining piece out, the threads were shot, so I continued on through and the resulting 'fix':

Lasted fine for the next 20 years, then sat quietly undisturbed for another 17 years, until a month ago when I started to take things apart to replace gaskets and seals:

Yep, the driver side bolt snapped off inside the block. More fun..

 

[micruz60]

Challenges, every day!
We shall overcome...

 

[ginmtb]

I apparently got lucky taking mine off the engine block. But it did shear in the housing. Replaced with new. Think the bolt is still sitting in old one lol.

 

[65swb45]

Just fyi - I get parts like that shipped here for repairs . Most times it's repair filling old cast aluminum parts that have been eaten by bad antifreeze or broken fasteners , like thermostat housing necks , bases , water pump castings , ect...
Some jobs are quite time consuming , but for some reason I enjoy it - nice to be able to save rare or nla parts for folks .
You really can't rely on a Mapp torch , it's not a fast enough heat nor concentrated enough .

Sarge

Unlike Weber Sarge and others, I have had a hundred percent success rate with a handheld propane torch.

 

[JohnnyC]

X2 on the propane ... I don't know if one would consider it wrong but I always heat the housing

Never had issue with the other engine bolts... I think when you leave the oil leaks it prevents the rust from creating problems ... Just as Mr.T designed it

 

[Racer65]

The car is now in good hands, with Georg.

 

[ginmtb]

The car is now in good hands, with Georg.

View attachment 1208087

Dang I want one of those decals! Maybe you can pick one up for me when you pick up your cruiser. Have had plenty of work done there.

Oh and the MAPP gas works for me and can get things pretty hot (full disclosure this was two torches to do this but I don't think you need to get the bolt that hot)...

 

[Racer65]

Dang I want one of those decals! Maybe you can pick one up for me when you pick up your cruiser. Have had plenty of work done there.
View attachment 1208128

No way man. You have to break two thermostat housing bolts to get that sticker!

 

[oldschool4wheeling]

OK, has anyone ever broken the bolts to the lower thermostat housing, or do those come out without a fight? The last thing I want is a broken bolt in the engine; that's why I'm hoping to leave the lower housing in place.

That is exactly what i was thinking. Trying to taking it off could open up a bigger

Edit: Posted this before I was through reading the thread.

But I really like what @JohnnyC said about oil leaks!! That will definitely keep them from seizing.

Im thinking we should add a new item to the FSM preventive maintenance schedule. Especially, since these rigs are 30 plus year old. I think every time we open the hood we should start Kroil or PB blaster every nut and bolt we see. Then when we finally have to replace a certain part, it should in theory "fall off" .

 

[orangefj45]

Well. Turned out the old tried-and-trued "weld a nut to it" worked great. Just as always. And of course the second bolt broke off too.
Good thing we've got a little experience with this.

Georg @ Valley Hybrids & Cruiser Brothers

First step: clean threads with wire wheel.

 

[orangefj45]

Second step: thread a nut into the broken bolt.

 

[orangefj45]

Third step: weld! Don't tack weld the nut on there. Burn it on! You need the heat from the welding process to transfer along the broken bolt to help break up the rust, corrosion and calcium build-up around the threads.

 

[orangefj45]

Step four: grab a wrench and twist the bolt back and forth to pulverize the corrosion build-up. Washing it off with something like PB Blaster doesn't hurt. Once it starts to tune freely, unscrew it. If it starts to snug up, run it back in.
Repeat process until you've got this puppy in your hand.

Georg @ Valley Hybrids & Cruiser Brothers