T-stat housing big fitting leaking coolant

[ScottD]

I am having trouble sealing the large threaded fitting on the bottom of the t-stat housing. There is a large fitting that screws directly into the head and then a flared metal hose that screws into that, which goes to the heater control valve. The large fitting into the head is the one I'm having trouble with. I've tried teflon tape and teflon thread sealant and it seems to keep squeezing it out of the threads.

Is there another sealant I should try? The FSM recommends something called Perfect Seal. Should I try Form-A-Seal Gasket (the brush on stuff)? Any suggestions appreciated.

[BIGBRUDDA]

Its a tapered pipe thread. Try more "elbowgrease"(tug harder).

[ScottD]

So you're saying more torque? :-)

That's tough with it in the car (L-body) but I can remove more stuff and get a strong arm on it.

Thanks for the reply. This is a brand new engine, I just fired it for the first time yesterday and am looking forward to putting some break-in miles on, but need to fix this issue first.

[contraption22]

I have this gooey stuff that GM offers to seal head bolts that go into coolant jackets. Seems to work really well.

[ScottD]

Ok, I'll keep that in mind as well.

[cordes]

Its a tapered pipe thread. Try more "elbowgrease"(tug harder).

+1 It is 3/4" NPT. I always just use a hose barb fitting from HD there, but you could get a setup like the factory by shopping in the same isle.

[turbovanman²]

Did you use liquid teflon sealer, and yeah, tighten it up,

[ScottD]

Yep, used liquid teflon sealer.

[GLHNSLHT2]

you didn't crack the head by screwing it in too tight did you?

[ScottD]

I don't think so because it has leaked from the get go. If it keeps leaking that is something I'll consider.

[ScottD]

THANKS to all who responded. I actually had two issues. One was I needed to torque the big fitting a little bit more (thanks BIGBRUDDA). The second was I'm using a stock T-stat housing and that was actually seeping a bit too and running down the housing and down the fitting.

PS Mike that gooey stuff you have sounds like a personal problem, you need to put away the provocative pics of VP nominee Palin .....

[contraption22]

PS Mike that gooey stuff you have sounds like a personal problem, you need to put away the provocative pics of VP nominee Palin .....

Its not my fault. She's a VPilf.

I'm glad you got your leak fixed!