Cooling system

[Tcapper]

Hi, I'm working on my heater (the heat comes and goes). The system has been burped as per other threads and the car isn't overheating. I'm suspecting a vacuum leak to the heater controls. I was wondering what this valve is that is attached to my heater hoses. Any help is appreciated. Thanks.

[KevinK]

That is a heater water control valve. It turns off the the hot engine coolant to the heater core. Most mustangs do not have this valve. It is hower a generic type of valve used on many Fords. The older mustangs with AC used it. Amber your car has aftermarket ac?

You can by pass it to see if your heat improves or just hook it up directly to vacuum. What year and options on your mustang?

[Tcapper]

It's a 1984 GT vert. and it has vintage air, so that would explain the valve. I forgot to mention that both heater hoses are hot and when the heat does flow it's great. I've just repaired a blocked heater core on my daughter's car so I know that the heater core isn't blocked. That's why I'm thinking that it's possibly the blend door. It's not really a problem as is the car is only driven in the summer but it is puzzling.

[Lowetlx]

The blend door is cable operated. You can check the operation of the cable and door behind the glove box.

[Tcapper]

Just checked and it appears to be operating. I do a lot of work on cars, but now I'm at a loss. I might try to bypass the heater water control valve, but that still doesn't explain why the hoses are both hot and still no heat. I think I'm missing something.

[Lowetlx]

Is the heat blowing out all the correct vents but it’s just not hot? The first thing I would do is make sure that valve is working properly. Pretty common for a heater control valve to get plugged up or stuck.

[Tcapper]

sorry watching the hockey game. Everything is blowing where it should, just no heat. Air conditioning is working fine too. Gonna trouble shoot more tomorrow. GO JETS GO!

[erratic50]

That valve follows a GM design used on the G body and many others. What’s good about it is they help reduce the chances of blowing the heater core. What’s bad is they are prone to malfunction and breakage. Either put on a new one that’s connected to full vacuum along with a flow restrictive for the heater core, or eliminate it and add a flow restrictor.

[cb84capri]

That's not the GM one though. The GM valve is plastic and prone to cracking. Best bet is to get rid of that and do it the Ford way with a restrictor,

Cale

[Tcapper]

I checked and I do think that is the problem. Anybody know a part number or where I might be able to get a restrictor. Also will eliminating the valve affect the operation of the AC. Thanks for all the help.

[cb84capri]

I guess I don't know anything about the Vintage Air setup. I notice now that your hoses are going wide of the engine the way non-a/c car do from the factory. Where is the evaporator in your car? Before you do it the way I suggested, you might want to make sure with that system that the valve is not necessary,

I went to Princess Auto with my heater core when I had it out and found a socket that fit in the heater core inlet. Without the restrictor, they balloon out and will eventually spring a leak.

Cale

[Tcapper]

Yup I guess I have to do a little more research on this setup. I bought the car with it and I believe there's only one company in the city that does the install. I'll check with them this week. Thanks again.