I have had to replace the thermostat housing on my 1999 2.0lt Zetec Ford Focus twice over three years, the last time was two months ago and already the seal is leaking, I know its a bit of a design fault on the Focus but was wondering if when fitting a new housing if the mating surfaces require anything other than just a clean, or do they just bolt together?
The thermostat housing is unlikely to require replacement being new as its probably just the rubber seal which is only a few quid but a new housing kit from my local Ford dealer is over £100.
Just wondering why I've had to do this job three times already and might be missing something.
Stephen.