Focus thermostat housing

[IanCress]

I've replaced the thermostat housing on my 2004 MK1 2.0 Focus, but I can't get it to seal correctly.

The housing comes in two parts, and coolant is leaking where the two parts meet. I've tightened the screws as much as I can (wrecking the heads of two of the three screws) and it still leaks. Am I supposed to apply some sealant or something on the mating faces? There was nothing there when I took the old one apart.

[lemonslap]

IanCress said:

I've replaced the thermostat housing on my 2004 MK1 2.0 Focus, but I can't get it to seal correctly.

The housing comes in two parts, and coolant is leaking where the two parts meet. I've tightened the screws as much as I can (wrecking the heads of two of the three screws) and it still leaks. Am I supposed to apply some sealant or something on the mating faces? There was nothing there when I took the old one apart.

There should be a rubber seal between the two parts, are you sure the old one isn't still in the recess?

[IanCress]

Found the issue. Turns out ECP have the wrong part listed for the Focus thermostat. The thermostat I was trying to fit was slightly too small so the rubber seal was allowing coolant to flow past. Re-fitted the old thermostat (it was working fine when I removed it) and the leak has stopped.