Heater Control Valve Question

VaCat33

VaCat33

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CAT Member
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Hi All

I am replacing the heater control valve on my MkI. I got one of the replacement valves from SS. Unfortunately, before removing the old valve, I did not check the orientation of the dash control lever in relation to the control lever on the valve.

Could somebody please tell me in what position (forward toward front of car or back toward rear of engine compartment) the control lever on the valve is suppose to be when the control lever on the dash is in the HOT and COLD Positions.

Just to be clear, when referring to the control lever of the valve, I am referring to the point where the heater control cable affixes to the valve control with the screw that tightens down...NOT the little tab that moves though the slot on the valve.

Thanks.
 
A Picture might help

OK, I have the new valve on the car. If the control lever on the valve (the circular tab on the bottom where the cable connects) is in this position, where should the dash control lever be...HEAT or COLD?

Thanks again.
 
Hi Jim,

I am thinking the dash control mechanism would be the same on both your Mark I and my Mark IA. As I move the lever from left to right (from cold to hot), the cable extends forward in the engine compartment. I would first verify that is also the case with your car.

If so, I would suggest moving the lever on the valve as far rearward as possible (toward the windshield) and put the dash lever in the cold position. Attach the cable end and housing to the valve with everything in this position. Then test by moving the dash lever to the right all the way to hot. The cable wire should move the valve lever forward opening it to allow water to flow to the heater core.

I suggest doing it this way to ensure the heater is truly off (cold) at least in the off position. If you do not get fully range of movement of the dash lever to hot, at least there you know it is off in the cold position. There is also some adjustment possible in the outer cable positioning at the lever end of the control if its current positioning is somehow limiting full range of motion. (Not easy to get to as I recall...)

Hope I have understood the question correctly and some of this proves helpful.

Best regards, Gene
 
Gene et al

My cable does the exact opposite. As I move the dash lever from cold to hot, the cable retracts. So that means from the position of the valve lever pictured when I move the dash lever to hot it would pull the valve lever toward the rear of the compartment. I think that opens the valve and allows the heated coolant to flow to the core...do I have that correct.
 
Hi Jim,

Very interesting, certainly did not expect that difference in cable operation. I recently repainted and put new labels the dash controls surrounds. May have messed up the order of the lettering. I have cold on the left and hot on the right as things now stand.

Subject to direct info from a fellow Mark I owner, I would say put the valve lever as far forward as possible with the dash lever in the cold position. That way as you move toward Hot the cable retracts and pulls the valve lever toward the windshield. Assuming of course your labeling order is the same as mine...

If everything is connected with the valve lever as far forward as possible but with the dash lever in Hot, my thinking is the lever could not move to Cold at all, since the cable pushes out in that direction and the valve lever is already all the way forward.

Again apologies if I am not fully understanding the question or how things are moving.

Best regards, Gene
 
Resolved

Hi!

I spoke with the guys at SS this morning and although they could not remember the exact open/close orientation of the lever on the valve, they provided a simple test: blow into the inlet tube…if the air flows freely the valve is open; if it is restricted or blocked the valve is closed. Based on my air flow test the closed position of the valve lever is as pictured in my original post. Based on that info I was able to finish off the install.

Thanks
 
How's it work now?

The MK1 valve I have is stuck in closed position. I have a Honda one I got part number searching old posts someplace on now. I am hesitant to buy the repop early valve or even the MK1a and later version which is supposed to be better.

Have seen the conversion to a hidden valve in heater core, aka matrix scuttle box but do not want to mess with the cabling and control arms.

Has the early reproduction valve from S.S. served you well?
Any other decent replacement ideas?
 
So Far...So Good

Warren

After 2+ months, the replacement valve from SS is working fine. I have put about 400 miles on the clock since replacing it.

The opening and closing mechanism seems to work more smoothly, although it does not completely close in the cold position. That is, however, more of an issue with the range of my control cable than the valve itself.
 
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