I replaced what I believed to be a cracked and leaking OEM thermostat housing with the commonly available aluminum housing kit. Since then, I've been plagued with seepage from the joing between the main thermo housing and the thermostat cover. This is the joint that is sealed by the rubber ring that wraps around the thermostat itself. I disassembled and put in a new thermostat seal, but the problem remains. I can actually see it dripping from this joint.

It seems to me that the aluminum housing and thermo cover do not squeeze the rubber seal enough, i.e., the recess in the main housing is too deep.

Anyone else had this sort of problem with the aftermarket aluminum housing? Any ideas on fixes? I'm considering "re-shaping the recess in the main housing with JB-weld or RTV to force it to really put the squeeze on the seal.

Thanks-

 

The rear bolts on the t-stat housing are very difficult to reach and tighten. This is true for both the OEM plastic and aftermarket aluminum. Are you certain you have these bolts tight? And before you go out in the garage and snap one off, I only mean tight like 10-15 ftlbs. (As I recall they are only 8-10 mm and they seat in aluminum threads, so please do not overtighten!) Is the O-ring seated in the groove? It could have been pinched and broken.

I would NOT attempt a fix using JB Weld or the like. There is too much pressure for anything other than a proper fix. gordo

 

Thanks for your sound advice. However, The leak is not at the manifold attachment, but rather the joint that pinches the thermostat itself via the thero rubber seal. Since my initial post, I decided to add a gasket to this joint. I fabricated a gasket and coated both sides with hylomar, and reassembled. Hasn't dripped a drop since. That's the way most thermo housing joints are designed anyway, so I'm not really inventing anything new.

Thanks again.

 

testzzzzzzzzzzzzz

 

I would pull the thermostat out and check the rubber gasket to see if it had shifted in the housing. If that were the case I would use the old gasket if the new one was damaged and another is not available. As for the “T”stat if I recall it only goes in one way and then it must be positioned correctly to allow the cap to be bolted on properly. I wish I had taken photos of that to show you.

 

I installed one of the aluminum kits for the first time recently. My vendor warned me that the supplied aftermarket thermostat seal was junk, so I assembled everything with factory seals...in this case, with the new seal that came on the new factory thermostat. The casting and machining was very good, as was the final result.