The 'E' Type Forum

Found a leak yesterday on my series 2 lhd car.
Its leaking coolant inside the cabin around where the throttle pedal is.
The strage thing is that its only leaking when the circulation thru the heater is turned off, when its on there is no leaks.

Can this be caused by a leaking heater valve/connection at the firewall, or is the leak caused by more pressure when circulation is turned off?
Really hoping to avoid changig the heater pipes inside the cabin.

Hi Frank....as in another post this week re leak in cabin...put in some Bars leaks to hopefully seal it up.. Steve

Frank,

The pressure in the cooling circuit should be the same no matter if the heater valve is open or closed. When open all you are doing is adding a extra volume to the cooling circuit (think short circuit and long circuit), and given both circuits are closed loop (by pressure cap on radiator) they should have the same pressure before and after opening the valve (albeit with a transitory spike as you crack open the heater valve).

So, I don't think the "pressure theory" is the one to follow. I would tend to think that it is some sort of failure on the heater valve, although all my thoughts of failure would end up with fluid in the engine bay, and not in the inside of the car.

It's an interesting problem you have, that's for sure.

David

Thanks for advice. The valve seems easy to replace and it is not very expensive. Considering buying one to test.

I had a leak similar to this. It was caused by someone leaning on the heater valve whilst checking the car. Seems to pipe was not inserted fully into the valve so the slightest pressure caused it to leak. Fix was to drill out the rivets and re-do them making sure the pipe was pushed fully home.

The way the valve is connected to pipe is quite stange by the way. Dont forget the small rubber ring seal that goes in the heater valve spacer.

How far in should the pipe go? Fully through the alloy block, O ring and then into the valve itself?