MGB & MGA Heater Control Valves
Heater valves frequently fail and need replacing in MG’s…
Even back in the 1960s and 1970s, heater valve replacement was often required in these cars.
A “Blown” heater valve will let you know in various ways:
-Since the valve is directly above the ignition distributor, when it fails, it will dribble antifreeze onto the distributor. This will cause missing, back-firing, rough running, or it may actually cause your engine to stall out entirely.
If your engine starts running rough, and it is accompanied by the smell of antifreeze, you can almost bet that your heater valve has failed.
-Once a heater valve has failed, it will start leaking antifreeze (coolant), and it won’t tale long before the coolant level in your engine drops enough that overheating occurs.
Remember, the fluid volume in the cylinder head is quite small. If you leak out a litre or two of antifreeze, the cylinder head may actually run DRY. This is a prime cause of a cracked cylinder head $$$$$.
The heater valve contains a rubber diaphragm and this is what usually fails. There aren’t any repair parts available. This means that a new valve will be needed. We’ve just brought in a decent supply of brand new MG heater valves.
Fits any 1955 – 1980 MGA or MGB.