1979 thermostat housing to head not sealing

[Rambo]

I rebuilt my head and now that it is back together the thermostat housing to head leaks. When installing the gasket wasnt seating correctly but i have resolved that problem by cleaning and glueing the gasket to the housing and bolting it on. Ive confirmed that it is seating correctly by taking the temp sending unit off and looking in the housing. It still leaks and my only theory now is that the gasket is to thin and it doesn't get compressed enough before the housing bottoms agaist the head. Has anyone had this problem before?

[TimpanogosSlim]

Although a flying saucer type thermostat fits in there and works, unless you live in a colder region the external thermostat is preferred because they flow much better. And the threads in the head for the water neck aren't really designed to withstand a lot of use. The external thermostat is standard on 1800 and 2000 engines.

At any rate, it's possible you have the wrong gasket in there.

When you say glued i hope you mean RTV silicone?

Anyway, the correct procedure for form-in-place gasket making is to apply the silicone, install the part semi-loose so the excess silicone is just starting to squish out the sides, wait for the silicone to cure, and then torque fasteners to spec. The wait for cure thing is why gasket maker compounds are often available in a quick-set formula. Toyota claims that their FIPG is ready for oil contact in 20 minutes. At $12/tube (or $17/tube at the dealer) it better be.

[Rambo]

Although a flying saucer type thermostat fits in there and works, unless you live in a colder region the external thermostat is preferred because they flow much better. And the threads in the head for the water neck aren't really designed to withstand a lot of use. The external thermostat is standard on 1800 and 2000 engines.

At any rate, it's possible you have the wrong gasket in there.

When you say glued i hope you mean RTV silicone?

Anyway, the correct procedure for form-in-place gasket making is to apply the silicone, install the part semi-loose so the excess silicone is just starting to squish out the sides, wait for the silicone to cure, and then torque fasteners to spec. The wait for cure thing is why gasket maker compounds are often available in a quick-set formula. Toyota claims that their FIPG is ready for oil contact in 20 minutes. At $12/tube (or $17/tube at the dealer) it better be.

1) I do have a external thermostat i just called it thermo housing.

2) The gasket is brand new from autoricambi

3) Yes i used RTV.

[TimpanogosSlim]

In that case it sounds like you have the with-internal-thermostat gasket instead of the without-internal-thermostat gasket. Thickness is different.