Well guys it's not good, With the engine running you can see just a tiny amount building at the join on the back and front (area highlighted by black box in first picture, doesn't seep when engine isn't on). Most of you know I did a flush and refil last week and now I have this problem. Thermostat is a Ford one, Ford o-ring too, though I do have a new one from Repco as well. Surge tanks is down about 1.5cm. Note: I put no kind of sealant or vaseline on the o-ring beford installation.

How do I fix this and what is the process? I don't wanna empty and refill again. Just get the thermostat off without making a huge mess, and top it up from there, thanks guys.




NOTE: That grey glue like looking stuff at the join was there before the empty, flush and refill last week, I thought it best not to touch it.

I had the same problem after a flush.

To remove enougth coolant as to take of the thermostat housing, I siphoned from the overflow bottle. Under the cap, get your hose (about 1/2" size) right down the filler hose that goes to the radiator underneath. If you siphon till it can't siphon any more you will reduce the coolant level to about 1/2 way up the radiator, plenty below the thermostat.

I took off my housing and gave it a good cleaning with a wire brush. When I put it back on, I didn't rely just on the O ring seal, I put silastic around the outer seal of the housing. All so far so good.

Cheers, I'm off the stop now, I'll get some silastic.

Couldn't have put it better myself! Exactly what I do.

just remove ALL of the old silastic and sealant rubbish, get a new genuine o-ring and refit it all. i've never had one leak yet that i'd cleaned properly