I have had a coolant leak for some time from the thermostat housing. Unfortunately there is no drain point in the system, so a hose needs to be disconnected. Messy!
First I drained down the system and removed the thermostat housing. This was cleaned up where it mated to the block. Next I applied Hylomar blue sealant to the mating surfaces. After a bit of fiddling I got the thermostat and housing back in place, bolted up and filled ......... but it still leaked. So I repeated the process. It leaked again! So a glass of wine was called for.
After relaxing a bit, I thought of three reasons why this may be happening - the thermostat was not being correctly aligned, the bolts were too long and not allowing the housing to be nipped up or both.
So the next day I checked the bolts and sure enough one was not going in to the block far enough. The bolt was shortened a little to allow it to screw in fully.
Next I fit the rubber thermostat gasket in to the housing, using sealant in the recess where the rubber gasket sits. Then I put two tie wraps through the top of the thermostat and threaded these through the housing. I located the thermostat in place, making sure that the pressure release thingy was in the correct place (there is a recess in the rubber seal). Next I fixed the tie wraps around a bolt to secure the thermostat in the right place and so that it could not be moved whilst fixing. Sealant was applied yet again to the clean mating surface, before the housing was offered up and bolted in place. The tie wraps were removed, the hose reconnected and the jubilee clip tightened. The system was then re-filled gradually, making sure that no air was trapped (tip - get the front of the car higher than the back). Success!
|Thermostat housing re-fitted|
Whilst messing about stopping the leak above, I noticed that two of the fan fixings on the driver's side had broken after only 1,200 miles!
|Broken fan fixing. Tie wrap can now be seen below it.|