What is this leaking? (Pic)

[427ford]

Those heater control valves were fairly common "back in the day" (cars / trucks from the 60's and 70's). My '94 Ranger doesn't have one but I'm pretty sure the one in the picture's only purpose it to cut off flow to the heater core. I remember a buddy back in high school had an old beater car..that had a manual shut off vlalve up by the fire wall. He'd shut it for the summer and open back up for winter.

 

[Dave-X]

Thermostat?

I looked around and it seems that a 195° thermostat is what's normally installed, but would installing something like a 180° thermostat cause any problems? To cool it earlier.

Thanks.

 

[427ford]

That's just what the t'stat is rated at to open. Probably wouldn't hurt and I don't think it'll be of any benefit. Coolant is going to run well over that (220+ degrees), anyway. The only reason it doesn't boil is it's under pressure (which raises the boiling point of water). If your $5 pressure cap is venting too soon, and not holding the 11 or 13 pounds of pressure... the coolant could boil. Steam doesn't remove heat as well as liquid

First thing I look at with a vehicle that runs hot.. the cap.