coolant level in thermostat housing?

Hi All,

So I have searched and cannot find the answer to this particlur question.

if I check the coolant level by removing the bung on top of the thermostat housing should it be full or would I expect to find an air gap in it, with coolant visible about halfway up the thermostat?

This is without removing the expansion tank cap.

Cheers

should be full ,with cap off vehicle sitting level

Cheers James,

Ran it until it was hot, let it cool, took off the thermostat bleed cap and it was full.

left the expansion cap in place.

cheers

You need to make sure that you only remove one cap at once. If you remove the expansion chamber cap AND one of the caps from the radiator or thermostat housing then they will level out between themselves and the expansion chamber will fill up with coolant out of the engine. So leave the cap on and first remove the filler from the radiator then top it up and replace the cap then do the same for the thermostat and replace. Any small amounts of trapped air left after that should auto bleed through the Y pipe. If it doesn't then just make sure that the Y pipe is not blocked. It can take 20-30 miles to fully clear any air from experience. Also it's worth replacing the silly plastic radiator and thermostat plugs with brass ones from a plumbers just make sure you use the white PTFE tape.

its better with both tank cap and thermostat housing bung both off then fill till both over flow ,excess will be lost and you know its full