Looks like these valves should be operated from time to time, in order not
to start malfunctioning....
From: Larry Hoy [mailto:firstname.lastname@example.org]
Sent: donderdag 16 november 2000 1:05
To: Dave Tietz; MGList
Subject: RE: Replacement Heater Valve
>I'm getting tired of replacing my heater control valve in my MGB.
Me too. The straw that "broke the camels back" was a year ago. Turned on
the heater for the first
time, all the water leaked out of the head, apparently very quickly (did
anyone ever tell you the
temp sender doesn't send the temperature of air) and I blew a head gasket.
I was about 30 miles
from home on a cold rainy October night. Had to remove the valve, plug the
hole, and re-install the
valve; in the dark, and in the rain and cold; then I had to go get coolant.
Not a nice night! I
vowed that would never happen again.
> Has anyone replaced it with a reliable in-hose (1/2 inch) type - One that
could be inserted in the
heater hose either going into or out of the heater core?
Couldn't find a 1/2" one, found a 5/8" one, Factory Air 74628. AutoZone?
You'll have to figure
out the plumbing. There are adapters for hose, and there are hoses that
convert from 1/2" to 5/8".
If you want to find one of the conversion hoses you'll have to ask the auto
parts store counter
person to allow you to go into their inventory and check, take a tape
measure and the valve. If
they won't let you go back and check you're at the wrong parts store. When
you plumb in the valve
pay attention to the water flow arrow.
There are options for getting from the block to a hose, none of them simple.
Probably the easiest
is to take apart the old valve and, either cut off part of it and tap it for
a pipe thread, or seal
the outside end and use the old valve as an el. Either way, I would
recommend drilling out the hole
that is on the engine side of the valve to increase the diameter of the
hole. This will increase
water flow, and heat the cockpit of your car better.
To operate your new valve with the old cable you'll need to heat the end of
the cable and bend a
small loop in the end. It just slips over the rod at the end of the lever.
No need to fasten it
the cable to the rod, because the cable housing is held securely by a small
clip on the valve.
"OFF" on the valve is done by extending the cable, and "ON" is done by
shortening the cable. This
may be opposite of the MG valve I can't remember. Mine works correctly, but
I think I modified the
mechanism behind the dash that the heater control knob operates.
I can't give more details than this because my installation actually went on
my V8 conversion.