74 Duster heater valve vacuum or mechanical??

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twister360

twister360

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I need to get the proper heater valve for my Duster with factory AC. There is a nipple in place of the valve. I have looked for the valve online and each vendor shows a mechanical valve but I only have a small vacuum line nearby and no cable.

Thanks. Gary
 
I'm pretty sure the original-style valve is extremely "no longer available", but you can use a generic valve in place of it. The only thing to remember is whether the valve is closed or open with vacuum applied. I don't recall which style it is supposed to have.
 
TylerW said:
I'm pretty sure the original-style valve is extremely "no longer available", but you can use a generic valve in place of it. The only thing to remember is whether the valve is closed or open with vacuum applied. I don't recall which style it is supposed to have.
Click to expand...

Thanks for the replies!

I had a feeling it was vacuum operated, all vendors offer the mechanical. Hopefully someone will know the proper open/closed type of valve.
 
TylerW said:
I'm pretty sure the original-style valve is extremely "no longer available", but you can use a generic valve in place of it. The only thing to remember is whether the valve is closed or open with vacuum applied. I don't recall which style it is supposed to have.
Click to expand...

I'm going through the same issue with a valve for my 69 Barracuda which has a 70 Dart A/C system in it. The original valve is essentially " unobtainium" unless you find one on EBay at some ridiculous price. The valve needs to be closed with vacuum applied and a Four Seasons 74612 from a 80's Dodge truck application looks like it will work. $7 and change from Rockauto in the 5/8" hose side.
 
my 72 duster has a vacuum operated one. still works! lol

I would post here FABO for one, unless the rock auto truck deal won't work. lets hope it is the real deal.
 
barbee6043 said:
my 72 duster has a vacuum operated one. still works! lol

I would post here FABO for one, unless the rock auto truck deal won't work. lets hope it is the real deal.
Click to expand...

If yours is original, could you possibly look for a part number? I would like to locate an original before I try for the truck type valve.

Thanks, Gary
 
Thanks for the link Ted! It hadn't occurred to me yet that I couldn't just turn the valve around the other way if the action is left vs. right :D

While the heater experts are here, can I ask a related question... my '72 Dart has a heater box with only two cables (blend door and defrost/heater door, no A/C), but the dash levers have fasteners for three separate cables (blend door, defrost/heater door, and the third one must be for a heat shutoff valve).

Does anyone know which year A-body has a mechanically operated heater shutoff valve in the hose, controlled by that third cable? The reason I ask is that I'm having trouble ordering the proper Bowden cable - they seem to only be listed by year/make/model and what I'm interested in is the length!

I'm pretty sure I have a different year heater box and possibly non- '72 levers too, although the panel in the dash looks original...No idea if this car had factory A/C or not, I got it as a stripped shell. I'm committed to the existing heater box after modifying it for big-block valve cover clearance and installing it.

So, now that we know where to get a mechanical valve (Autozone has them for $15.99, the 74827 is pull-open, correct for my cables, and the 74828 is "reverse" (pull-closed). Summit has them too: http://www.summitracing.com/parts/fss-74827

Can anyone help me pick a cable? Stock appearance/fit is not important.
thanks!
 
On a non-AC car there is no heater valve. The coolant circulates through the core all the time and the blend door serves to shut off the flow of hot air.

Not sure what you got going with your heater control panel. Does it simply say:

OFF HEAT DEFROST

LOW TEMP HIGH


with a horizontal heater switch?
 
Yes, that describes my panel. (I assume you are referring to the horizontal fan switch?) It's quite possible I have different year heater box and control panel.

But there are most definitely pins and clamps for three control cables as I described, and only two cables on the heater box (one fresh air door which I thought was called the "blend" door, and one door to select between defrost and floor vents).

The pin on the temp lever moves the fresh air door to make the air hotter or colder, as expected. One pin on the off/heat/defrost lever moves the heat direction door from floor to defrost when the lever is moved between HEAT and DEFROST. So far so good.

The remaining pin, also on the off/heat/defrost lever, only moves when the lever is moved to OFF, so it has to be for a shutoff valve...

With no a/c, headers and maybe no interior, I don't want any more heat than I'll be getting anyway, so I definitely want the core off.

I got the 74827 valve today and now it's just a matter of finding a suitable cable and cutting the 5/8" hose to install the valve where the cable ends.
 
Pete in NH said:
I'm going through the same issue with a valve for my 69 Barracuda which has a 70 Dart A/C system in it. The original valve is essentially " unobtainium" unless you find one on EBay at some ridiculous price. The valve needs to be closed with vacuum applied and a Four Seasons 74612 from a 80's Dodge truck application looks like it will work. $7 and change from Rockauto in the 5/8" hose side.
Click to expand...

On my particular 74 the heater core is 1/2" X 5/8" with the heater valve going on the 1/2" side. The proper valve is Four Season 74690 which is 1/2" and normally open. No one makes this type of valve that physically attaches to the fender as the original. At least it will work, I'll just have to zip tie to fender brace.

The $7 valve is plastic, but if you want a quality Chinese made metal valve you have to set up and pay $45.00

Gary
 
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