Thermostat housing question

[fj40z]

The gasket on my thermostat housing started to leak a little bit, so I picked up a new gasket today and started to change it this evening, one side was a stud bolt, the other looked like a bolt and when I went to take it out it snapped like a twig. I got the housing off and there was quite a bit of bolt sticking out, but no matter how hard I tried I could not get the rest of the bolt out of the bottom part of the housing. Are both of these bolts stud bolts? I know one is but Im kinda thinking that the other one might be to since I cant get it out. And if it is and its ruined is there any other way of fixing it rather than replacing the bottom part of the housing that bolts to the block? Thanks for any help, and I apologize for the bad wording.

 

[Poser]

The fasteners used to retain the top part of the thermostat housing to the bottom housing are bolts, 8mmx50mm long, iirc. They are not studs. The factory Toyota bolts are soft, and typically are corroded to the point that they will fail when trying to remove them.

I replace them whenever I service a thermostat housing with 10.9 hardness bolts and use anti-seize on the threads and shank of the bolts to prevent the dissimilar metal corrosion from running rampant.


A little heat from a propane/Mapp gas torch may get that remaining part of the bolt out of the housing. Get the piece good an hot, and get after it with a vise-grip. It will come out.

After the piece is removed, if the threads are damaged in the housing, you can easily install a heli-coil or other threaded insert into the housing to make it serviceable once again.

If this sounds like too much work, just pick up a different lower housing.


Good luck!


-Steve

 

[Pin_Head]

And if it is and its ruined is there any other way of fixing it rather than replacing the bottom part of the housing that bolts to the block? .

I presume you mean that the bolt broke off inside the bottom aluminum housing. I have only seen bolts holding the upper and lower housing together. You can drill out the remains. The more time you spend centering the drill, the easier the repair will be. I would bolt it to a piece of angle iron and fix it to a drill press using the top part to center the drill.

 

[fj40z]

Yeah you are right Poser the metal those bolts are made out of is some of the softest metal I've seen, thanks to you and Pin_Head both for the ideas, Im going to try to get it out again tomorrow and I'll post up how it goes.

 

[Trollhole]

Like Steve said heat is your friend. I've fixed several that have snapped this way.

 

[yotawheeler]

i fixed one the other day on mine.... mine snapped off flush to the bottom of the housing so i drilled it out with 1/8th bit put an easy out and heated the bottom part of the housing with a propane torch..came right out

 

[psuknow98]

I have an extra housing... Interested?

 

[Cruiserdrew]

Buy the extra housing. I'm pretty sure they are discontinued by Toyota. I bought a new one from SOR, just so the next time mine needs service, I have the part. Those Toyota bolts in the t-stat housing are complete crap.

 

[Dusty 66]

New lower housings are available PN 66331-10040 for 69 to 79
and X2 on new bolts and anti-seize every-time....... good luck

 

[fj40z]

Well I got it all back together again with new bolts and liberal use of never seize, and I did get the stuck bolt out finally but I went a different route. My 2F is desmogged and the bottom of the therm. housing there is 2 outlets that are normally capped for the desmog. So instead of using the old housing I used one from a 1F, it doesnt have the 2 outlets so no need to plug them. It worked out real well.

 

[a77fj40]

i just want to say that i love this place. here i am out in my driveway with two broken bolts for my thermostat housing, cursing and swearing and wondering what to do now that my easyout just snapped in half. then i come inside and check out MUD and low and behold, there is a thread with my exact problem and a whole list of solutions. i love you guys!

i am going to try this tomorrow and i will let you know how it turns out.

thanks guys

db

 

[Coolerman]

If there is enough bolt sticking out you can use a stud extractor to remove it.

Just heat the stud as hot as you can get it without melting the housing, slide the extractor over it and turn it out.

 

[trekker]

If there is enough bolt sticking out you can use a stud extractor to remove it.

Just heat the stud as hot as you can get it without melting the housing, slide the extractor over it and turn it out.

Good Lord Coolerman. How in the heck do you get those pictures so fast? You must photo everything. I thought I was bad but you get the award.

btw, you got pm

 

[Coolerman]

I have over 6 gig of pics of this rig and it's pieces...

One of my jobs as part owner of a small company is web site work which means I have to know how to do picture manipulation. I use Paint Shop Pro for all of my work. I have all the pics here at work so... I can pull the pic up, crop it, fix it if it's too dark, shrink it down, then post it all in about 2 minutes.

Checking mail now...

 

[a77fj40]

ok so this all sounded good but i can't get the cover (top) of the housing off. it is completely frozen and no amount of pounding is loosening it up. any ideas/suggestions?

db

 

[Coolerman]

See if you can remove the two bolts holding the lower thermo housing to the block. Remove the entire housing and take it inside where you can work on it. You may have to drill it all the way out then re-tap it.

It may be make more sense to just get another complete housing and be done with it.

 

[bsevans]

See if you can remove the two bolts holding the lower thermo housing to the block. Remove the entire housing and take it inside where you can work on it. You may have to drill it all the way out then re-tap it.

It may be make more sense to just get another complete housing and be done with it.

The housing can be saved. I would buy a helicoil kit (available at most good automotive stores or McMaster-Carr) with SS Helicoils and install them. I would also use SS bolts with anti-seize. I found that after a number of years the gasket will leak because the mating surfaces become pitted. The only way I could keep the gasket from seeping was to thoroughly clean the surface with a brass wire wheel followed by an alcohol wipe and then use high temp RTV on both sides of the gasket. It's been three years and not a drop.
A point of information: If you break a tap or easy out off and can not remove it, a good machine shop can EDM it out. I broke a tap off flush with the surface and my friend who is a tool and die maker had a mill bit that milled the broken tap out and did not need to use an EDM machine. That was one damn hard bit.

 

[Coolerman]

Oh I agree 100% it can be saved! but....


E-Bay Helicoil kit $19.99 + shipping

Machine shop work $25? (Don't have a clue what a shop would charge to do this)

So figure $50 for parts/labor/gas to machine shop and time is free for arguments sake.

Used housing $15 tops?