'69 heater control valve
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Joined: Jan 2002
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From: BOULDER CREEK ca
'69 heater control valve making my car overheat?
I have a '69 smallblock TH400 with AC. I just got my heater control valve working, Vacuum appears to close it in the OFF and MAX AC positions, open in all other positions. however, when it is closed the temp goes through the roof. When the control is in any other position, and the valve is open, the engine temp stays normal...HELP
[Modified by HWY 9 - '69, 11:19 AM 1/21/2002]
[Modified by HWY 9 - '69, 11:19 AM 1/21/2002]
Le Mans Master
Joined: Aug 2000
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From: Semper ubi, sub ubi
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Re: '69 heater control valve making my car overheat? (HWY 9 - '69)
You and I have basically the same car, I had the same problem, then I discovered that my radiator was nearly completely plugged off. I had it recored and it cured my problems. When I had the radiator out I put in new radiator seals and fixed the shroud.
Drifting
Joined: Oct 2001
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From: Westampton NJ
Re: '69 heater control valve making my car overheat? (HWY 9 - '69)
When I installed my new heater core, I just bypassed the heater control valve. I figured that I really didn't need to worry about it since I installed my OWN valve in the supply line. It is a manually operated ball valve that will close off the circulation to the heater core during the summer when I close it.
My radiator has been recored (yay, for still having original tanks!) and it works great. Car never goes above the mark inbetween the first two written temps (I'm really tired, so I'm drawing a blank, but think they're 100 and 210). The mark is the one without numbers.
My radiator has been recored (yay, for still having original tanks!) and it works great. Car never goes above the mark inbetween the first two written temps (I'm really tired, so I'm drawing a blank, but think they're 100 and 210). The mark is the one without numbers.
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From: BOULDER CREEK ca
Re: '69 heater control valve making my car overheat? (rainman69)
mine runs right at that first line also, exept when the heater valve is closed, then the temp climbs very fast. i flushed the radiator last year, when i changed all the belts and hoses(it came out pretty clean, and the tubes didnt look fouled or anything). the temp is fine, even on 100 degree days in the summer(even in traffic), but for some reason when that valve closes, something gets unhappy. i cannot turn the AC control to off or Max (the two positions that close the heater valve) or the car will overheat. Anyone know why???
