Water Valve Motor / Heater Control Valve

1992MustangGT · Nov 22, 2009

Hey guys, I'm still putting together my 67 Cougar XR7 and I need some advise. Right now I'm trying hook up the vacuum lines under the dash for the heater / AC box. I have a vacuum schematic for a 67 Mustang (can't find one for a 67 Cougar). I assume that since the Mustang and Cougar are basically the same car and share many of the same parts, that the vacuum schematic for the Mustang would be the same for the Cougar.

In the vacuum schematic there are 4 vacuum lines (which are color labeled; black, white, red & blue) coming off the "Vacuum Regulator on the Control Assembly" (heater and a/c selector switch mounted on the dash between the driver's door & steering column; also has a vent as part of the assembly). The black vacuum line goes from the "Vacuum Regulator on the Control Assembly" to the vacuum canister resevoir, which is mounted on the passenger side fender apron in the engine compartment by the fire wall (the vacuum canister resevoir is also connected to a vacuum port on the intake manifold). In line with this black vacuum line is a "tee" that allows another line to go from this black vacuum line to the "water valve vacuum switch", which is mounted on the front of the heater/AC box. Coming out of the other side of this "water valve vacuum switch" is another vacuum line that goes to the "water valve motor" (the vacuum line from the "tee", through the "water valve vacuum switch" and onto the "water valve motor" is a purple line. So in all actuality, this black line coming off the selector switch on the dash connects to both the vacuum canister and the "water valve motor", via a "tee" in the line.

Ok here's my confusion and my question...Can someone tell me what the purpose of the "water valve motor" is and if I need it? This "water valve motor" is identified at the local parts store (autozone) and by Mustang's Unlimited as a "Heater Control Valve". However, in the schematic I have it's called a "water valve motor". The reason I ask if I need it is because my car didn't have one mounted on the firewall. I have 3 classic Cougars (67 standard, 67 XR7, and a 68 XR7) and none of these cars have a "water valve motor / heater control valve". What is the funtion of this valve and do I need it? In the schematic, there is one vacuum port in the top of it and 2 water ports in the side of it; one going to the heater core and the other goes to the water port in the intake manifold....

If you log onto Mustangs Unlimited - The Premier Source for Mustang, Shelby and Cougar Parts and Accessories and do a search for part number OA44 or type in "heater control valve", you will see the part I'm talking about and the ports on the valve. Any help you can offer is greatly appreciated

2+2GT · Nov 22, 2009

The valve is critical to proper operation of the AC/heat. The hot water supply must be cut off while operating AC or vent, or the incoming air will be both cooled and heated. A functional and reasonably similar replacement can be had from most Mustang vendors. Cars with heater only didn't need them.

1992MustangGT · Nov 22, 2009

Yep, that's the valve Mustangs Unlimited shows and they charge $59.95 for it and $42.95 for a plastic one. Autozone has the plastic one for $12.99. Seems to be a rip off to charge $60 for the same vavle. Guess I'll be going to Autozone.

Ok, here's another scenario....although my car came with A/C, all the A/C parts under the hood is gone. So I'm not using A/C, but I still have the A/C box under the dash and all the interior A/C stuff. So as far as controlling the coolant flow to allow the A/C to operate properly probably wouldn't be a concern at this point; is that correct? But I am concerned about the vacuum line that goes from the "tee" in the black line to the "water valve vacuum switch" and then onto the "water/heater valve" that you were talking about. What function does the "water valve vacuum switch" have (mounted on the front of the A/C box)? What does it do? Does it control vacuum going to the "water/heater valve", which in turn controls coolant flow? If that's the function of it, then since I'm not needing to control coolant flow to allow the A/C to function properly (since I don't use the A/C because of missing parts), then am I correct to assume I can just bypass or disconnect (or in my case, not go purchase & install) the "water/heater valve"? If so, then I can just plug the "tee" in the line going to the "water valve vacuum switch", because it isn't being used because of no A/C; is that correct also?

2+2GT · Nov 22, 2009

1992MustangGT said:
What function does the "water valve vacuum switch" have (mounted on the front of the A/C box)? What does it do? Does it control vacuum going to the "water/heater valve", which in turn controls coolant flow? If that's the function of it, then since I'm not needing to control coolant flow to allow the A/C to function properly (since I don't use the A/C because of missing parts), then am I correct to assume I can just bypass or disconnect (or in my case, not go purchase & install) the "water/heater valve"? If so, then I can just plug the "tee" in the line going to the "water valve vacuum switch", because it isn't being used because of no A/C; is that correct also?

Yes, the switch on the case controls the coolant valve.

If you don't plan on using the AC, or even the "vent" function, you don't need the valve.

'Course, if you dn't fix the AC at some point, you're crazy. The best thing you can do is get the Sanden compressor kit, which will give you the compressor adapter brackets, and special hoses. Add a condenser and dryer and the AC will be working again.

1992MustangGT · Nov 22, 2009

Can you tell me where to find the Sandsen A/C kit your talking about (part number and company)??? I would like to get the A/C running, but not sure what parts I'll need. Also, do I need to replace or clean out the "A/C core" (not sure what you call it) that's inside the heater/AC box under the dash? There is still a little bit of oil in it cuz it leaked out when I removed the AC/heater box (I replaced the heater core and blower motor).

JonK · Nov 23, 2009

Here's one place that makes it, I'd give them a call if you don't see the factory replacement system on their site, should be most everything that just goes under the hood. I would change your system over to R134 as R12 is outrageous $ now.
1967 or 1968 Mustang-Cougar Air Conditioning System | 67 or 68 Ford Mustang Mercury Cougar AC

Another supplier is:
Vintage Air - Inventors of Performance Air Conditioning - www.vintageair.com

If you cap the vacuum to the valve it won't be working anyway and these replacement systems have their own valve that comes with the kit I believe. You can just remove the valve for now and put a piece of 5/8" hose from the engine to heater core, that's how the factory nonA/C cars came. I wouldn't spend $50 on a valve you won't be using and will probably replace when you get a system.

Jon

StangDreamin' · Nov 26, 2009

For '67, the vacuum schematics are almost the same for the Mustang and Cougar, so the schematic you're looking at will do. The one exception between the cars is of course the vacuum routing for the headlight doors.

If your Cougar's "eyes are always open" (the headlights are visible even when they aren't actually on); you might consider throwing 5 bucks at THESE GUYS and ask them to include the headlight door vacuum schematics. Their prices are generally a little higher than vendors like MU; but then again, they have stuff that MU doesn't carry - like the vacuum motors for the headlight doors. They contract out a lot of "Cougar only" rebuilds/reproductions that you can't find elsewhere, unless MU and the like start buying from them.

(Now if they would just "contract out" some decent repop '71-2-3 quarter panels)

1992MustangGT · Nov 26, 2009

StangDreamin' said:
For '67, the vacuum schematics are almost the same for the Mustang and Cougar, so the schematic you're looking at will do. The one exception between the cars is of course the vacuum routing for the headlight doors.

If your Cougar's "eyes are always open" (the headlights are visible even when they aren't actually on); you might consider throwing 5 bucks at THESE GUYS and ask them to include the headlight door vacuum schematics. Their prices are generally a little higher than vendors like MU; but then again, they have stuff that MU doesn't carry - like the vacuum motors for the headlight doors. They contract out a lot of "Cougar only" rebuilds/reproductions that you can't find elsewhere, unless MU and the like start buying from them.

(Now if they would just "contract out" some decent repop '71-2-3 quarter panels)

When you say "These Guys", who are you talking about? What company?

2+2GT · Nov 26, 2009

That would be Classic Auto Air. They make kits to convert from OE compressor to a Sanden compressor. They don't use the old generic type, either, they use a good one. The kit includes adapter brackets to put the Sanden where the OE pump was, hoses to connect the Sanden to your factory unit, and the compressor. If you are missing anything else, they can tailor the kit to include that, too. I have bought such stuff through Glazier Nolan, very cooperative, and close by for me, but not required.

1992MustangGT · Nov 26, 2009

The discussion was regarding a vacuum schematic for the headlight doors. Stangdreamin mentioned to contact "These Guys" for a schematic. I was asking what company he was referring to.

2+2GT · Nov 26, 2009

1992MustangGT said:
The discussion was regarding a vacuum schematic for the headlight doors. Stangdreamin mentioned to contact "These Guys" for a schematic. I was asking what company he was referring to.

If you look closely, you'll see the phrase "THESE GUYS" is underlined, which means it's an HTML link to:

1967 Mustang & Shelby Vacuum Schematic Manual - Repro at West Coast Classic Cougar :: Specializing in 1967, 1968, 1969, 1970, 1971, 1972, and 1973 Mercury Cougars

1992MustangGT · Nov 27, 2009

2+2GT said:
If you look closely, you'll see the phrase "THESE GUYS" is underlined, which means it's an HTML link to:

1967 Mustang & Shelby Vacuum Schematic Manual - Repro at West Coast Classic Cougar :: Specializing in 1967, 1968, 1969, 1970, 1971, 1972, and 1973 Mercury Cougars

Ok, thanks for the tip. I checked them out and they have a good schematic. Thanks again....

randyray01 · Jan 28, 2011

follow up question:

just bought a valve for my ac/heater on my 68 289 coupe....i see the pic in the post about how it sits and so that was helpful. i also know its online with the shorter hose...those 2 things aside...heres my question. when its installed and running, depending on the rpms and speed, i feel ac coming from the heater vent at my feet on the drivers side....i also hear the heater "hiss" whether its on or off (while my car is on in other words i always hear the heater on...maybe it always has and im just noticing it?)...anyway...the heater and ac do work which is good. im just worried that 1., i hear the heater on and #2, the rpms sometimes push air out of that vent and sometimes doesnt. the vac seems tight at the valve altho i have no idea about where it leads to thru the firewall into the cab....is all this normal?? THANKS!

Water Valve Motor / Heater Control Valve

1992MustangGT

2+2GT

1992MustangGT

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1992MustangGT

JonK

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StangDreamin'

1992MustangGT

2+2GT

1992MustangGT

2+2GT

1992MustangGT

randyray01

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