need help...broken stud for thermostat housing

[ty**20]

I just flushed my coolant with new oem toyota red and install new thermostat. there were a small leak around the housing. So i tightened all the nuts but i overtightened the furthest nut (one closest to fire wall) and the stud broke off. Can the broken stud be taken off to be replace when dissembled the housing all over again? Any suggestions will be greatly appreciated.

Thanks,

[dc_98_cam]

I wouldn't be surprised if the broken stud already had a crack in it, which would mean that the housing at that location wouldn't be properly snugged down ... resulting in the leak that you observed ...
That doesn't really help you much though ....
If there is enough remaining stud length to get a grip on .... you could try removing it.
If the stud breaks off at the surface, then maybe you could try drilling and tapping it ... If the stud goes all the way through to the waterside, there is probably some sort of sealant on the stud threads.

Another thought ....
The smart thing to do would be to get a propane torch and gently heat the broken stud remnant... the part that is left sticking out ... repeat this two or three times .... The idea is to deactivate the loctite or sealant compound that is probably on the stud threads. You want to be really careful not to overheat anything and cause additional damage. Try just to heat the stud and not much else surrounding it .... Maybe some sort of mini-torch would work best.
Then try to get a grip on it and twist it out.

Just curious ... can you post a picture or two?

[hill8570]

Originally Posted by ty**20

I just flushed my coolant with new oem toyota red and install new thermostat. there were a small leak around the housing. So i tightened all the nuts but i overtightened the furthest nut (one closest to fire wall) and the stud broke off. Can the broken stud be taken off to be replace when dissembled the housing all over again? Any suggestions will be greatly appreciated.

Thanks,

Well, the stud's replaceable (part # 90116‑06070) if you can get it extracted.

[ty**20]

I suspect cracks too because it was hard getting the inlet pipe off due to the pulling and rocking in the limited space. The stud broke right at the nut so I guess there will be a good chance of pulling the remaining piece out. I will take pic tomorrow cuz it dark and the housing is quite hard to get some snaps off in that condition.

Thanks,

Originally Posted by dc_98_cam

I wouldn't be surprised if the broken stud already had a crack in it, which would mean that the housing at that location wouldn't be properly snugged down ... resulting in the leak that you observed ...
That doesn't really help you much though ....
If there is enough remaining stud length to get a grip on .... you could try removing it.
If the stud breaks off at the surface, then maybe you could try drilling and tapping it ... If the stud goes all the way through to the waterside, there is probably some sort of sealant on the stud threads.

[ty**20]

Originally Posted by hill8570

Well, the stud's replaceable (part # 90116‑06070) if you can get it extracted.

That is awesome. Thankyou so much. I might have make a trip to the local dealer for this.

[JohnGD]

Did you also use a new thermostat gasket? But I'd think even the old one should hold.

I'd double check to make sure the thermostat gasket surfaces on the housing and block are clean before the next install. If there was a previous leak then the coolant crust can interfere with the seal.

[Pvt-Public]

Once you get it out you can probably match it up at any auto parts store just be sure you get a metric stud. If you really need to you can even use a metric bolt of the correct length and pitch.

[ty**20]

yes i used a new gasket. i will make sure to do that during the repairing.

Originally Posted by JohnGD

Did you also use a new thermostat gasket? But I'd think even the old one should hold.

I'd double check to make sure the thermostat gasket surfaces on the housing and block are clean before the next install. If there was a previous leak then the coolant crust can interfere with the seal.

i'll see what the toyota dealer have and keep your suggestion in mind.

Originally Posted by Pvt-Public

Once you get it out you can probably match it up at any auto parts store just be sure you get a metric stud. If you really need to you can even use a metric bolt of the correct length and pitch.

[ty**20]

alright got the broken stud out. now off to the dealer for a new one. does anybody know what kind of sealant i should put on the new stud. there seem to be several loctite thread-locker kind (red, blue, green, black)out there, but which one is better suited for this situation?

[Mike Gerber]

Congrats. How did you get the stud out?

For the correct type of sealant, I would ask at the dealer's parts department. It might even show on their sytem along with the stud, or even ask a tech if you can talk to one.

Mike

[hill8570]

Originally Posted by ty**20

alright got the broken stud out. now off to the dealer for a new one. does anybody know what kind of sealant i should put on the new stud. there seem to be several loctite thread-locker kind (red, blue, green, black)out there, but which one is better suited for this situation?

If the new stud doesn't already come with something on the threads, I'd use Loctite red for the threads going into the housing, and Loctite blue (or nothing) on the nut.

[ty**20]

i used the advice fenixus and dc_98_cam gave me. torched the remaining stud with a small torch propane and use vise grip pliers to turn the stud off counter-clock wise. be careful when you handle the flame, it can burn other parts around the block. yeah i will ask the dealer people about the thread locker sealant when i pick up the new stud tomorrow (thanks hill8570 for the part number). the studs weren't in stock so they have to order it.

Originally Posted by Mike Gerber

Congrats. How did you get the stud out?

For the correct type of sealant, I would ask at the dealer's parts department. It might even show on their sytem along with the stud, or even ask a tech if you can talk to one.

Mike

[dc_98_cam]

Glad to see you got out of a difficult situation ....
It looks like the small torch did the trick with the sealant on the stud.
It could have turned out different ... drilling ... tapping ... an oversize hole ...

The only other suggestion is to find out the factory specification for the torque on the housing nuts .... Maybe you won't have anymore cracked studs or other broken parts.

[fenixus]

glad you were able to pull it out! phew, was worried you may end up drilling and tapping, but can't really imagine doing that is such a PITA area ... unless engine was removed ... never mind.

FYI, 1mz-fe uses 69in-lbs / 5.75ft-lbs (strongly recommended to use a 1/4'' torque wrench with in-lbs scale on that) on thermostat housing nuts and no more breaking the studs

I have a feeling that the old one could have been already cracked though as mentioned above. it very well fits to description of the initial leak over there (not holding the housing right to start with).



BTW, which thermostat did you use? now would be the last chance to swap it with Toyota OEM or Kuzeh (same as OEM, received this one in a Toyota box)

[ty**20]

Yep the good old torch trick does it again. i'm happy no drilling was involved.

Originally Posted by dc_98_cam

Glad to see you got out of a difficult situation ....
It looks like the small torch did the trick with the sealant on the stud.
It could have turned out different ... drilling ... tapping ... an oversize hole ...

The only other suggestion is to find out the factory specification for the torque on the housing nuts .... Maybe you won't have anymore cracked studs or other broken parts.

Moving the air filter box system will give you way more room to work on when dissembling the thermostat housing. i wish knew that in the first place. I always use oem stuff. i got the thermostat and gasket from Gary. all his magnets and note pads are all over the house. Thanks fenixus and dc_98_cam

Originally Posted by fenixus

glad you were able to pull it out! phew, was worried you may end up drilling and tapping, but can't really imagine doing that is such a PITA area ... unless engine was removed ... never mind.

FYI, 1mz-fe uses 69in-lbs / 5.75ft-lbs (strongly recommended to use a 1/4'' torque wrench with in-lbs scale on that) on thermostat housing nuts and no more breaking the studs

I have a feeling that the old one could have been already cracked though as mentioned above. it very well fits to description of the initial leak over there (not holding the housing right to start with).



BTW, which thermostat did you use? now would be the last chance to swap it with Toyota OEM or Kuzeh (same as OEM, received this one in a Toyota box)