Morris Minor Owners Club

Hi
Has anyone got an easy solution to clearing air locks in heater pipes. Mine is a 1966 traveller with original engine. any advice would be useful. Bob

dont try to do it facing down hill! Flush it out with a hose pipe.

Normally the action from the pump would push the air out with the flow of coolant. Perhaps there is a restriction somewhere stopping the full flow of coolant and so air is not clearing. It could be the passage ways in the heater matrix are partially blocked. I would give the whole system a good flush out including a back flush before refilling and testing again.

I've always found that sustained engine revs for a while (e.g. taking the car for a short run) clears any air - even when the system has been totally drained. If it's not clearing, then it could be (as mentioned) that the matrix is blocked, or I suspect even more likely that the heater tap on the head is seriously restricting flow. That is easy enough to check by whipping the heater hose off with the engine running to check flow.

when you run the engine do it with heater on and the radiator cap off once the thermostat is open it usually clears the air quickly , i usually keep an eye on the engine when its doing this and look for leaks when ive put the rad back on .