Heater valve leaking internally?

[Schon '02]

The valve plug is harder to rotate when its hot due to coolant pressure and differential expansion. When the engine is up to temp, is the control lever easy to slide or stiff? If it's stiff, and if there's slop in the shaft to plug fitment, you may not be getting the plug to rotate fully to the closed position. I'd recheck the plug for any subtle deformity where the metal shaft fits. AMHIK...

 

[Dudeland]

The valve plug is harder to rotate when its hot due to coolant pressure and differential expansion. When the engine is up to temp, is the control lever easy to slide or stiff? If it's stiff, and if there's slop in the shaft to plug fitment, you may not be getting the plug to rotate fully to the closed position. I'd recheck the plug for any subtle deformity where the metal shaft fits. AMHIK...
 

It is easy to move. When in the closed position the arm is strait down.


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[Dudeland]

I had another line of investigation if it was an earlier model single lever hot/cold lever.

My thoughts are adjusting the cable length at the valve to ensure it is closing properly when your lever is positioned to cold at the dash. Several have already suggested this and I concur.

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Yes. I double checked today. The arm is strait down when in the cold position.


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[Schon '02]

Maybe there are other variants out there, but in my case, the valve is closed when the lever is at the 7:30 position (small hand of the clock) and open when at the 4:30 position (viewed from the passenger side). The shaft has square end so the lever can only go in 1 of 4 ways; the shaft only fits one way on the Blunttech plug, which positions the square with points at 0/90/180/270 degrees; the square hole on the lever has its aligned with the sides parallel to the lever sides. So straight down would be half open for a Blunttech rebuilt valve.  

[Dudeland]

17 hours ago, Schon '02 said:

Maybe there are other variants out there, but in my case, the valve is closed when the lever is at the 7:30 position (small hand of the clock) and open when at the 4:30 position (viewed from the passenger side). The shaft has square end so the lever can only go in 1 of 4 ways; the shaft only fits one way on the Blunttech plug, which positions the square with points at 0/90/180/270 degrees; the square hole on the lever has its aligned with the sides parallel to the lever sides. So straight down would be half open for a Blunttech rebuilt valve.  

Thanks I will try to get a picture of the orientation of the lever from the drivers side.  I think we are onto something. 

[Guy Cocquyt]

Good point, when you push the dash lever to the right (hot), it is pushing the lever on the valve to to 4pm position and when you slide it to the left, (cool) the valve lever position is at 7pm. So the valve is closed at 7pm and open at 4pm..

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[Schon '02]

With the retrofit valve support bracket, it's possible the cable end or cable set screw are getting hung up in one of the fasteners bolting the bracket to the heater box. You may feel that the control lever has hit a hard stop, but it may not be the internal valve pin.

[E60coyote]

I recently rebuilt my heater box and control valve and had a similar issue. Luckily I found it on bench testing. I used the blunt tech kit with the plastic guts and found that the through hole in the “on” position didn’t line up perfect when assembled. There was some play side to side so I shimmed it so that it would stay aligned when assembled. Works great now. I suspect the shimming helped align for the closed position as well. 

[Dudeland]

On 10/18/2019 at 12:19 PM, Guy Cocquyt said:

Good point, when you push the dash lever to the right (hot), it is pushing the lever on the valve to to 4pm position and when you slide it to the left, (cool) the valve lever position is at 7pm. So the valve is closed at 7pm and open at 4pm..

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Yes 

[Dudeland]

4 hours ago, E60coyote said:

I recently rebuilt my heater box and control valve and had a similar issue. Luckily I found it on bench testing. I used the blunt tech kit with the plastic guts and found that the through hole in the “on” position didn’t line up perfect when assembled. There was some play side to side so I shimmed it so that it would stay aligned when assembled. Works great now. I suspect the shimming helped align for the closed position as well. 

I am confident when I close the valve that it is bottoming out on the stop built into the housing.  I am headed to the garage now.  I will see what is what. 

 

[Dudeland]

Ok so here is the verdict.

 

The plastic is messed up.  It looks like it was tightened to without having the metal bit aligned in it's socket.   You can see where it deformed the plastic.  I bent it back in place so it would engage the socket ok for now, and ordered a new one from Blunt (along with a clutch master cly).   Not the worst outcome, but a complete waste of an otherwise perfectly good part.  

 

This is what happens when you leave something not buttoned up and come back to it later.  You forget where you are and screw things up. 

 

I did take the opportunity to make sure that the metal socket that the plastic fits into is perfectly aligned, so two screws and a quick swap and I am done, no adjustment of the cable needed. 

 

Please learn from my $125 (CDN) mistake, I try not to make to many as stupid as this one. 

 

Regards