I did this mod to my '01 E-350 V-10 4 years ago. I've put pictures in my gallery. It works.

 

I noticed the same thing. What you need is a regular pipe thread 3/4" ball valve and 2 threaded nipples. I think the nipples I bought were 2" long and all thread. Thread the nipples into each side of the ball valve and they will fit the hose tightly and the threads give the hose something to bite on when you clamp it. I got everything at lowes

 

Question for IROC it and others who say don't do this mod. You are suggesting not to do this mod because the heater core could corrode without proper circulation of coolant. My question is, what is the difference of corrosion risk between running the motor with a shut off valve VS. the motor not running when the vehicle is parked? Isn't the corrosion "risk" the same? Doesn't the heater core pretty much empty itself out when you start the motor BUT BEFORE the thermostat opens? Isn't copper more resistant than the iron engine block? Please explain if I am wrong, which is a big possibility. My neighbor has hot rod and when he parks for winter he drains all fluids, so it would seem safe to me.

 

I finally successfully calibrated my A/C on my 2004 F150 FX4, I had been having trouble for the past 2-3 years. Every where I went to they wanted to change the whole system since my truck has a body lift they also told me that I have to put two electrical fans in front of the condenser. What we figured out was that we had to force air into the condenser in order to calibrate the a/c so, anyone out there having problems with their a/c calibration force air into the condenser in order to properly calibrate.
Now my A/C works better than ever plus my condenser and motor run cooler with those 2 fans. FYI:you can get these at any O'Reily's or auto parts store but, preferably racing performance. Thanks.

 

Do you have more info on this? I am needing to do the same thing with mine. How do I go about recalibrating the ac? Am I just supposed to install the fans so it blows constantly over the condenser? Do you have any pics of the fan? Thank you

or

even better a link to something I can read and have all the questions answered?

 

once you install the fans take it or if you know how to charge your ac with the required amount of freon using gauges.In my case the specialist just calibrated to the manufacturers specification.Here are some pics .

 

Question on this.

Some vehicles use this coolant route thru the heater core during warm-up before the thermostat opens to recirculate coolant within the motor to balance heat and avoid hot spots. (as I remember on some motors in the past)

Is this not an issue on the 4.6?

 

Bringing this one back up.

Has anybody else done this since and noticed a difference?

 

i just did the heater core shut off valve on my 04 f150 5.4 and it dropped the temp by 8* going down the road. average was 60* with 58* at best. now 50* and at idle i hit 46*

when i hit the recirc button nothing happens. no door closing or fan blowing harder sounds. i think this is why it is warmer going down the road. (fresh air getting in) i am going to look at that next.

but i would definatly do the shut off valve install.

 

Any 2008's do this?

 

my 05 never had good ac. then i moved down here to florida. it is essential that it work here mainly to make the wife happy, i generally roll the windows down as long as it is not raining. i took it in since i do not have the gauges and it was i am told a pound low. they also mentioned that the fan clutch was shot and that is real common with this model truck. i took the truck out of there and the ac was doing a good job until the first stop light and it went warm. took off driving again and it went back to cold. stopped at napa and got a new clutch for 60 bucks and took a half hour to install and the ac is excellent. still takes a bit to cool the dark green truck when its been in the blazing florida sun all day but the wife is not longer complaining so its all good.

 

Tried this mod because the AC was cool, but not as cold as I thought it should be in my 06 FX4 SCAB.
After the installing the valve and closing it off, the temp in the center vent read 38 degrees on high MAX AC setting with temp outside at 93 degrees doing 55 mph.
After putting the valve in the open position and going down the same road at same speed with the outside temp read at 91 degrees and the vent temp was 40 degrees. This was just one test and I plan to do a few more. 2 or 3 deg doesnt seem like a really big difference, although the air does feel a bit cooler and it was a few deg hotter outside when i ran it with the valve closed, so maybe that was good for another deg or two. So maybe 5 degrees difference, but that is better than nothing and planning on adding e-fans too. The R-134a charge is around 48 so its slightly overcharged...



Anybody have any good numbers on how much more temp drop at vent you will get by adding e-fans?

 

I think that change is decent, myself. Lately my air doesnt even seem to be keeping up unless its on max recirc...in my 08! WFO!!!

 

Come up to Wisconsin and try that, when it's -20 or worse.....

 

Okay, I replaced my fan clutch, no help, it was bad anyways. I crimped off my heater hose to see if that would help, nope. I checked the freon, it reads perfect according to the gauges. I tried switching from max to normal a/c, sounds like the blend door is moving and the speed pics up on the max side. I'm tired of having to run the blower at the loud roar in 85 degree weather to keep cool.