Jump to content

Leaky Thermostat Housing! :) Any Ideas?!


Recommended Posts

Hey guys, ive got an 83 Corolla and I basically swapped an Old old ooooooold 4k out and swapped an old 4k in. Just for a learning experience etc etc..


I got everything in and going but I had a water pump leak, so I took it off cleaned everything up nicely cut a new gasket out of gasket paper and the water pump stopped leaking, however the thermostat housing is leaking too, and I tried the same fix but its corroded and the new gasket doesnt fix it..


Any ideas guys? For home fixes, or is it worth just buying a new one?


Cheers in advance!

Link to comment
Share on other sites

Members dont see this ad

try using sand paper on both surfaces, a really rough grit, depending on how corroded it is, if its the housing that corroded just get a new one they go for about 30 from memory.


if its the part the housing bolts on to then give it a really good skim back with sand paper, make sure its a smooth surface so when you put a new gasket it should seal up nicely, and abit of silicone wont hurt it :)

Link to comment
Share on other sites

rather than sandpaper on the surfaces try and use something flat.


i think it is best to use a flat steel file so you can keep the surfaces flat, with sandpaper you run the risk introducing high and low points which will just promote leaking further.


i assume youve got something that looks like this:




you gotta get those surfaces perfectly flat, or at least as close as you can get without a milling machine.


easiest way is to grab the thermostat housing in the palm of your hand, grab a flat file, and gentily rub it back and forwards across the sealing face. don't go hard at it or you will make it worse!


the one on the engine not as easy to take off, but if i recall correctly on the k motor it was reasonable to get a file across the surface.

Link to comment
Share on other sites

Its because people pull the two bolts down too hard and slowly bend the flat surface on the cover. Easy to buy, I replaced one a year back, or file it flat again.


I scored a flat block of 12mm steel years ago and I use that with wet 'n dry sandpaper on for all the flatting jobs. Grab one if you ever get the chance.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


  • Create New...