Need help with heater hoses and control valve

[tpj71mach]

Hi All,

I am starting the install on the heater hoses and I have a few questions (here is where my lack of Ford experience kicks in). I realized that I do not know the flow pattern between the heater core and the water pump and block ports. Also, I am trying to buy a heater control valve and NPD has one without a bracket and has arrows indicating the flow can go in either direction for this valve. Unfortunately, this valve has been out of stock for the last month and they told me on the phone they do not know when they will get more in stock. CJ Pony (not my first choice for suppliers) has one but there is only one arrow cast in the case of it which seems to indicate the flow can only go one way, and this valve has a mounting bracket. Can someone please tell me which style of valve is correct for my 71 Mach 1 351C with A/C? If it is the style that NPD offers, does anyone know where I can get that style without waiting for NPD to get it back in stock?

Hemi Killer posted a great diagram (see attached) of the routing in a different post I found on heater hose routing which was very helpful in the routing aspect, but the drawing overlaps the two hoses as they run along the intake manifold. I am unable to determine for sure which hose is which from the engine end to the heater core end. It appears to me that the water pump outlet hose is the one that has the control valve in it and it is attached to the inboard port of the heater core and the hose attached to the outboard port of the heater core runs directly to the nipple in the block, is this correct? If it is, am I correct in assuming the flow runs from the water pump through the control valve and on to the heater core and then returns to the block? If this is the correct flow pattern then it appears that the CJ Pony valve's one way flow is backward to the bracket orientation. Where the bracket could be mounted on the intake the flow arrow points the opposite direction. It does look like the valve and bracket could be swapped around to work though. I appreciate any help I can get regarding the flow and the correct valve style and if anyone has used either of these valves themselves. Thank you

 

[Bill Kanode]

Hi All,

I am starting the install on the heater hoses and I have a few questions (here is where my lack of Ford experience kicks in). I realized that I do not know the flow pattern between the heater core and the water pump and block ports. Also, I am trying to buy a heater control valve and NPD has one without a bracket and has arrows indicating the flow can go in either direction for this valve. Unfortunately, this valve has been out of stock for the last month and they told me on the phone they do not know when they will get more in stock. CJ Pony (not my first choice for suppliers) has one but there is only one arrow cast in the case of it which seems to indicate the flow can only go one way, and this valve has a mounting bracket. Can someone please tell me which style of valve is correct for my 71 Mach 1 351C with A/C? If it is the style that NPD offers, does anyone know where I can get that style without waiting for NPD to get it back in stock?

Hemi Killer posted a great diagram (see attached) of the routing in a different post I found on heater hose routing which was very helpful in the routing aspect, but the drawing overlaps the two hoses as they run along the intake manifold. I am unable to determine for sure which hose is which from the engine end to the heater core end. It appears to me that the water pump outlet hose is the one that has the control valve in it and it is attached to the inboard port of the heater core and the hose attached to the outboard port of the heater core runs directly to the nipple in the block, is this correct? If it is, am I correct in assuming the flow runs from the water pump through the control valve and on to the heater core and then returns to the block? If this is the correct flow pattern then it appears that the CJ Pony valve's one way flow is backward to the bracket orientation. Where the bracket could be mounted on the intake the flow arrow points the opposite direction. It does look like the valve and bracket could be swapped around to work though. I appreciate any help I can get regarding the flow and the correct valve style and if anyone has used either of these valves themselves. Thank you

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I really like the sheen of the black paint you have used and am wondering where to get it am assuming you sprayed it on. I had my engine bay blasted to bare metal and would mine to look as good as yours. Thx, Bill

 

[tpj71mach]

Thanks, I also had mine blasted to bare metal and then I coated it with black epoxy primer. After I completed my repairs and re-sprayed it with primer, I then seam sealed it. I painted it with Eastwood 2K AeroSpray Ceramic Chassis Black spray paint, in the satin finish. It is a rattle can version of a 2 part epoxy paint. I sprayed this in my attached home garage and did not want to use my spray gun and a Por15 type product, to try and keep fumes down. I painted the engine compartment and the whole underside of the car with this product. Although I did use the gloss black of the same product on the differential carrier so it would stand apart from the floor of the car. I was impressed with the way it lays out, especially for a rattle can, and how it looked once it cures. As I remember it was about $30.00 a can but it was worth it in my opinion. I am looking forward to seeing pictures of your engine compartment when it is done.

 

[Sheriff41]

For the valve, try searching for a Motorcraft YG-136. Can't help with the flow right now; can't access my references from work.

 

[tpj71mach]

For the valve, try searching for a Motorcraft YG-136. Can't help with the flow right now; can't access my references from work.

Thanks Sheriff, but this is an old post that a member replied to me about the paint that I used for the engine compartment. I have since resolved that concern, hopefully semi-correctly, haha. I appreciate your readiness to assist though, that's the best part of the members on this forum.

 

[70cobrascj]

Thanks Sheriff, but this is an old post that a member replied to me about the paint that I used for the engine compartment. I have since resolved that concern, hopefully semi-correctly, haha. I appreciate your readiness to assist though, that's the best part of the members on this forum.

Do you know which valve you used?
And do you know if it is normally open?
What I mean is will water flow thru it with no vacuum applied to it?
Thanks.

 

[70cobrascj]

For the valve, try searching for a Motorcraft YG-136. Can't help with the flow right now; can't access my references from work.

Here is some more confusion on this valve. I ordered one from NPD that was supposed to be for 65-73 mustangs with A/C. But this a normally closed valve. And in their description they list a YG-136 as an equivalent. The one they show that is normally open isn’t even close to being the right one. There are some expensive NOS ones on ePay but are they normally closed also?

 

[Steve McMahan]

Yea, as I remember, when you turn on the AC, it opens the vacuum to that line and closes the heater valve, so normally open is the valve you want.

 

[70cobrascj]

Yea, as I remember, when you turn on the AC, it opens the vacuum to that line and closes the heater valve, so normally open is the valve you want.

Yes it is what I have finally ordered geez
Would have been nice to not waste 35 dollars on one that was listed as being the correct one. Live and learn.
Thanks

 

[Steve McMahan]

We’ve all been there

 

[Spike Morelli]

I believe , that the heater valve is connected to the inboard nipple at the firewall, by a dedicated , molded "S" bent hose, and from the valve to the front by regular heater hose. Check it out, I bought the molded hose from a Mustang parts dealer, probably NPD, but I'm sure they all sell it. Of course, what you've done works too. I don't see anyone mentioning that "S" hose. Am I wrong?

 

[70cobrascj]

I believe , that the heater valve is connected to the inboard nipple at the firewall, by a dedicated , molded "S" bent hose, and from the valve to the front by regular heater hose. Check it out, I bought the molded hose from a Mustang parts dealer, probably NPD, but I'm sure they all sell it. Of course, what you've done works too. I don't see anyone mentioning that "S" hose. Am I wrong?

There are some NOS hoses on eBay but I bought a performed Napa hose and just need to cut to length.