bjtstarfire

What is the best way to check the operation of a HCV on a 61 Olds (It is vac. operated) or the heater t-stat?

Should I just connect the vac line from the HCV that goes to the t-stat directly to a vac source?

Is the valve normally closed then opened when vac is applied?

Some background: Heater core is not blocked, water pump is good, coolent level is correct, hoses are fine, no air bubble. When the heater is on the fan blows cool air so the blower motor is functioning and the vac that controls the master blower switch mounted on the heater core blower housing, inside the engine bay, is good.

Ben

Happy Holidays and Motoring (When me and my daughter go for rides looking at the Christmas lights it gets pretty cold - she needs a blanket due to no heat).

Oldsguy

sounds like you are going to do it right, another way to gaurantee that water is flowing through the core is to simply leave the return hose to the control valve open and let it dump down the side of the engine in the front of the firewall. I would think that as soon as you start the engine the water will start flowing as the water pump is not clutch operated, you should only have to let it dump for a few seconds. Of course the water would still be cool but that would verify circulation to the valve inlet AT LEAST. Then you can also, try running it w/o the valve. After the engine heats up you should have HOT air through your vents unless there is some other problem. That's my two cents anyway.

ozoneblue

Try installing a flush T in the return hose unscrew cap to bleed system.Also make shure you have a good radiator cap so the system builde a little pressure Ive had this problem on late models

bjtstarfire

Thanks guys