Antifreeze leak

[zoob]

The tube that comes from the top of the radiator to the top of the block where that meets the block there I am getting a pool of antifreeze on top of the block the clamp is tight it appears that where the tub connects to the block that piece has a seal between it and the block does this ever go?

289 engine

 

[zoob]

What is this seal called?

 

[70_Steve]

Thermostat housing gasket.

That looks to be an aluminum thermostat housing. I've never had much kuck with them. They always corrode and leak. Use a cast iron thermostat housing.

 

[phred]

The aluminum housings do tend to leak. I've had success with makeing gaskets from cork and glueing the whole assembly to the intake with RTV. Also I prefer studs in the intake instead of using bolts.

 

[stock1970]

bars stop leak..

I know everyone is going to jump on this and say dont use it, it clogs this and that.. but i have used in on several of my cars in the past and never had a problem. used it on a 75 mustang when i was a kid and that motor did not die until i sold it 15 years later.. I have it in my current bronco and can run at 180 all day long on trails, in traffic, down the highway. ect ect.. i think overheating is due more to buildup in the waterjackets and a bad radiator to begin with.. i used it this last time to stop a small gasket leak between the timing gear cover and block.. no problems yet..

 

[BUCKNBRONK]

bars stop leak..

Use stop leak crap only in a emergency it will plug up your radiator and heater core. just replace the gasket, if the thermostat housing is corroded change that too. not a bad time to put a new thermostat in as well.. Do it right the first time and be done with it.

 

[Viperwolf1]

Never seen a non-aluminum thermostat housing for a sbf. Those chromed ones are the ones that leak. Usually they use o-rings.

 

[72Sport]

Most auto parts stores around here sell cast iron thermostat housings made in China. They are crap. The area the hose clamps on is not round so the hose will not seal. The groove for the thermostat housing is not deep enough. Not sure about the stock ones. I have a serpentine system

I have been chasing similar problems. I found that the groove in the thermostat housing that the thermostat fits in was not deep enough and it was uneven. The gasket would compress on one side and not on the other. I made up a fixture to hold the housing and took it to a machine shop and had them make it deeper and square to the gasket surfaces. That fixed the problem. You might check yours after you remove the housing. See if the thermostat flange is above the surface of the housing. Make sure the housing gasket surface is flat also.

I had other problems also. I went to Autozone and got (loan) a radiator pressure tester. Took it up to 15 lbs and let it sit a couple of days. Gaskets compress between the block and timing cover over time and things begin to leak.
Another thing you might look into is the spring type hose clamps. They work great on new hoses. When the hoses get hot and soft the clamps tighten up. The screw clamps just get loose and begin to drip until you notice a leak.

 

[deltarat]

Mine leaks there too. I tried new gaskets and rtv and bought a new housing from BCB- the one with the O-ring. It stopped for a while but I noticed anti-freeze on the water pump the other day.

 

[gearida]

It doesn't look like the upper radiator hose clamp is tight to me, I can see the edges of it. Use the rule of thumb, you should be able to slide you finger over the clamp and not feel and level difference in the hose-clamp-hose. Take your thermostat housing off and use a file or glass and sand paper to make sure the surface is truly flat. make some gaskets and apply a very thin layer of RTV to both sides of the gasket. Make sure your t-stat is correctly installed too. I like the red lock-tite sealer that looks like jelly rather than RTV, can't remember the number.