Thermostat housing

[Roadie800]

I have a thermostat housing (water outlet) that leaks. The 289 has an aluminum Edlebrock intake and there was an aluminum housing on it when I bought the car. It leaked so I bought an original cast iron housing. I installed it with a standard gasket and put RTV on it but it still leaks.

I watched a few Youtube videos and one guy recommends getting a chrome plated housing that has an O ring instead of the standard gasket. Anyone here have any experiences with these?

[poboyjo65]

had 2-3 of the chrome ones with o ring,they all leaked. Last one I got from oreillys for a 70's 302 ,it is aluminum with a regular gasket & hasn't leaked yet. I always use a just a little of the sealant to glue the thermostat on to the housing in its groove & let dry then put it on. this is to keep from the thermostat falling down during assembly . if that happens one of the ears can break off of the housing when you tighten up the bolts.

[Caveman49]

What Johno said Never had any luck with chrome ones, aluminum or stock is best IMHO. Clean everything real good, both surfaces, put t-stat in correctly. Make sure to tq to specs, and let it set up for a day before adding coolant. At least that’s the way I do it, haven’t had any leaks so far…keep us posted on progress.

[Joe Travers]

I would only add to use anti-seize on all bolts threaded into aluminum and don't over-torque to try and stop a leak.

Joe

[Jims65cyclone]

Was talking to a guy at PF gathering this year who has a chrome housing on his. He was planning to change it out for a plain aluminum one because he said that was the second chrome one he had installed, and both leaked at the HOSE connection. He couldn't tighten the hose enough to prevent the leakage. Of course, that drips into the same valley on top of the WP that a bad gasket seal leaks into. May be worth checking to be sure it's not your hose connection that's leaking. Wrap a rag around the hose connection, go for a ride and see if the rag is wet when you get back.

Jim

[poboyjo65]

& if you do get a chrome one to seal it has a short lifespan ,I guess the antifreeze is hard on the chrome ,it will start flaking & eventually leak at the flakes. also a gasket is much easier to find if you have to service away from home. the chrome ones are hard to seal the first time,but after it's run awhile & you take it off the chrome around that o-ring can get rotten & sealing it will only get more aggravating.