After installing a brand new thermostat and gasket (on my car) I noticed a constant leak/drip at the housing. Tried reinstalling the thermostat about 3 times thinking the gasket wasn't sitting right. ( I think I can change a thermostat in about 5 minutes now...lol) After finally sanding the housing smooth and clean ( after seeing your video) the leak was finally gone. And there wasn't much buildup on the housing but just enough to cause a problem. Thanks!

This is the method I used to fix my situation: Thermostat housing was leaking like crazy so I kept tightening the bolts, thinking it would solve the leak, ended up breaking the bolt and now I had a broken bolt and a leaky thermostat. To remove the broken screw/bolt I had to make a tiny hole on it using a cordless drill and some very small drill bits, used penetrating oil as lube and after a good hour or so of drilling in incremental sizes (1.5mm, 2mm, 3mm) I was able to create a little hole big enough for a reverse drill / broken bolt extractor to fit in and get that pesky broken bolt out of there. From what I gathered researching for this issue is that these leaks are definitely caused by the previous gunk/rust residue creating an uneven mating surface between the block and the thermostat housing/gasket. To clean it off I used a razor to remove the chunky residue, very carefully not to scratch the metal, and then I used wet sandpaper grit 500, 1000, 2000. Doesn't need a lot of sanding just enough so that the surface is smooth, doesn't need a mirror finish. Give your new thermostat mating surface a quick little 2000 grit sanding as well just in case. And then clean both surfaces with a little bit of alcohol and let it evaporate, make sure its bone dry. After I used an RTV or Gasket Maker, and put it on the mating surface, just a little bit all around, it really doesn't need much at all, just enough to make a thin film and I installed the new thermostat and housing by hand tightening the bolts, afterwards waited at least 24h before torquing to final specs. Some RTV are different and you don't need to wait, it should say on the box. About the torque, you're better off seeing what grade and diameter your bolt is, and searching online the recommended torque values for it, because my car's torque sheet was a bit confusing and originally I ended up torquing 20nm on a bolt was supposed to be 10.5nm (8.8 grade 6mmx16mm bolt) which caused the broken bolt in the first place. So be careful with the torquing and look up the bolt specs and torque before properly tightening it. And it worked, no issues so far!

I didn’t know! ReelTease always with the tips

Great tutorial. Unfortunately I didn't watch it when I was installing a new housing, so it began to leak and eventually I lost my coolant mid drive. Oops.

Good man. I sheared a bolt on mine and can't get a weld on the recessed bit of bolt and have heard too many horror stories about easy outs to use one so am going to try running with 3 bolts !

You saved my bacon!

nice job -

Hi,today i had the same problem, i saw the leaking from the thermostat.I changed a month ago,i didnt change the gasket,in fact i didnt know.I will do what you say,i just want to ask if its necessarily to put gasket clue and also if it is a possibility the water coming from the head gasket The engine is Suzuki dt 40 1992.Thanks

Looks like my car has a leak coming out a bolt, it started small leak and now it’s a huge leak

what about if i just put silicone gasket

where is thermostat?