I’m having a constant leak at the upper radiator hose. The thermostat seal and thermostat are fairly new. Upper radiator hose is good, no cracks and still in good condition.

Today I installed a new thermostat housing to try and fix this leak. I thought this was my problem because the old housing was very rusted. However, the leak came back!! It looks like it’s leaking between the hose and the housing. The clamp is tight.

I don’t know what else to do. I might just order all new parts since they’re so cheap in case there are cracks I’m missing.

Any suggestions?

 

Clean it off, start the engine, wait for it to start leaking. It might be leaking around the bolts.... did you put sealer on the bolt threads?

 

I really tightened the hose clamp as tight as I could. I figure if I break something, I’ve got new parts on the way. That seemed to stop the leak for now. Once the new parts come in I will swap them all out again.

 

did you use a gasket or rtv to hold down the new thermostat housing? if the old housing was very rusty did you make sure to clean out the inside of the upper rad hose? any old rust chunks stuck to the inside of it could cause a leak.

 

My hose (albeit a used one) was tough to seal. Kept tightening the hose clamp and it finally stopped.

I have a feeling it's the surface of the nipple. Rust and pitting. I might butter it up with rtv next time.