[Mgs] Heater Air Control

[PaulHunt73]

Anything in the heater circuit can cause reduced flow, including the core 
itself and the metal pipe that carries the return flow back to the bottom 
hose.  Unfortunately replacement valves are pretty poor, The original lasted 
30 years, the replacement less than 10.  If the detent is missing but the 
hole is clear I'd tap the hole and uses a grub-screw, even if you could get 
the correct control (and there are many with different configurations) they 
are expensive.  Either that or get a cheap second hand one and if the wrong 
type perhaps swap the spring and pip over.

PaulH.

----- Original Message ----- 
> ... The spring on the shaft of the air control that holds the knob is 
> missing.