MK111 Heater Problems

[pete2bram]

All of a sudden the heater on my MK111 has stopped heating....air con is ok, cooling system is ok [new water pump recently fitted] and temp gauge keeps a perfect average and I don't loose any water [air con auto water valve mod has been done]. I know it could be an air lock but has anybody else out there been here and had a similar problem and how does the heater matrix valve work ? and what's the best way to dissipate an air lock.
Please.
Pete.

[bgrieger]

Originally Posted by pete2bram

All of a sudden the heater on my MK111 has stopped heating....air con is ok, cooling system is ok [new water pump recently fitted] and temp gauge keeps a perfect average and I don't loose any water [air con auto water valve mod has been done]. I know it could be an air lock but has anybody else out there been here and had a similar problem and how does the heater matrix valve work ? and what's the best way to dissipate an air lock.
Please.
Pete.

The heater VSV is the most common failure. Bypass the valve and plug the vacuum source line into the heater valve itself (the nipple sticking out the top of the whole unit), not the electric switching valve under it. If you suspect an air lock, lift the nose up several inches, open the radiator cap and start the car with the heat on.

[Jeeves]

It's not an air lock.

Try what I posted here: http://www.toyotanation.com/forum/t96727.html