Super Duty & Heavy Duty1999 to current Ford F250, F350, F450 and F550 Super Duty with diesel V8 and gas V8 and V10 engines
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So, I decided to give it a whirl... it was $20 so what the heck!?
Here's the valve (I had picked one off a Ranger, but the diaphragm was bad):
Here's where I'm gonna put it:
Here it is installed:
Down under the passenger's side of the dash is where I "T'd" into the white vacuum line:
A closeup of the whole thing... I managed to save the vacuum lines and a "T" off the the Ranger I got the first valve from so it all looks OEM:
I drilled a hole though the rubber grommet beside the black one that was already in there. It's tricky to find it, but all you have to do is reach behind the inner fender well through the wheel opening and fish around in there for awhile. I found that the valve drops the temperatures about 10*! WOW!!! Not bad for $20... now if I can just get my system cleaned out, I'll be set! PM if you have any questions!
The heater core (inside the box under the instrument panel on the passenger's side) has hot coolant running through it all the time. The air conditioner evaporator coil is also in there. Ford controls the temperature of the output duct air by "mixing" the air coming through both those cores.
If you want MAXIMUM-COLD air, you need to shut off the engine coolant running through the heater core. That's what this valve does when in the MAX A/C position.
There are other ways of doing this, including installing a manual valve in a heater hose, but this is automatic, and only in MAX.
hmmmm...not familiar with this mod, but you're saying this can help out AC system? And get about 10 degrees cooler? Considering it's going to be 90 this weekend in Ohio you may be my new best friend
What exactly is the part that you purchased?
Thanks for your information!
Just as a side note, I wasn't able to find this part at Napa or CarQuest... all they had was the one way valve. The only place I could find that had the valve was Advanced... you can also get it at Auto-Zone. Both of the them have the valve under the same part number, #74809. Just remember to get some vacuum line while you're in there!
I have contemplated doing this mod on my 04' but honestly I have mixed feelings as whether its worth it. The reason I say that is my dad has an 03' thats identical to my truck in every way except its a CC and his came with this vaccum switch to cutoff the coolant flow. My truck didn't come with the switch but my A/C is quite a bit colder than his. Both trucks owned since new.
A before and after temperature reading at the vents may make me do the mod. Need to see some evidence that its worth it.
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