Wonder if I could get away with using a 3/4" PEX ball valve? How tight does the hose fit over threaded 1/2" pipe? The 3/4 PEX is actually smaller.

 

Well I am VERY pleased with the ball valve modification. No more blowing hot air under moderate to aggressive acceleration. Also it blows quite a bit cooler. It blows as cool on "warm" as it used to on "cool".

 

Glad it helped. I had a tech at the dealership ask we what is was for and I told him. He said he was going to give it a try.
I like cheap and simple fixes...

 

I'm assuming that cutting off the flow won't hurt anything on these trucks. I know the old F150s like my 77 has a vacuum actuated cutoff valve....but I know these motors are ALOT different than my dinosaur 460.

 

Also just wanted to say that a ball valve with 3/4" PEX ends works PERFECTLY for this. The inside diameter of the heater hose is 5/8" which is already designed to be used with 3/4" PEX fittings. It's also a one piece unit, which makes the install much easier and look better as well.

Plus, the 3/4" PEX ball valve has a larger inside diameter itself, which shouldn't restrict flow like a much smaller 1/2" ball valve.

 

I had mine thru 2 winters and the 3rd summer now and no problems.
Thanks for the info on the pex valve... I'll check into this.

 

In the pipefitting world we call that "full port".

 

New owner of a used f150 2011. Ac sucks. Does this solution have and adverse impact on the vehicle?

 

On our 06, the a/c just would not do the job in stop and go traffic, but was real cold when you got moving.
First thing I did was get foam pipe insulation and tie raps and insulated the a/c hoses and metal pipes( this does help)
But I was still not happy,so I added an electric pusher fan in front of radiator. It only runs when the a/c is on and I put a switch next to the cigarette lighter so I can shut it off on the high way.
Now that really works, it's cold now,even in town
I hope this will help someone

 

There are many things to do to maintain a cold AC. Many are simple maintenance tasks like cleaning the condenser and engine radiator (radiator doesn't have much to do with it but as long as you're down there...). operating the system in the driveway on a hot day, check to see that the low-pressure side (larger metal pipe) is sweating all the way back to the compressor. IOW, look at the compressor and see the suction line sweating. Its commonly said that if it does that, its doing all it can do. I look at it as an indicator that everything is working, but if you're not getting an adequate temperature drop at the registers, something still is not right. The idea of bypassing the heater with the hot coolant is okay but it masks the real problem of the blend door not closing to the heater core.
Going back to the original question, the dealership is not lying; the ACs on the trucks in those years does act funny. My 2007 has always seemed to 'delay' turning on the compressor when re-starting to leave a parking place. And it definitely will turn the compressor off at more than half-throttle.
I don't mess with the new ACs, at least not yet, but back in the Freon 12 days I would shoot some Freon (with oil) into the system when it started getting weak. I have measured 35 degree F air at the dash registers at 80 F ambient. On a 1976 GMC van, I had the air so cold that once when I had a band show in a hot summer downtown venue, I had about five band members in the van cooling off before the show. It must have been 95 F out there. After about five minutes of my AC they actually begged me to turn it off. On these older trucks it is likely that there has been some leakage over 8 or 9 years so the best thing is to get that checked by a professional after you do everything you can first.
Another quick story; my dad had a 1963 Ford with the add-on AC under the dash. Once I was following him and mom to the beach on a blistering summer day and I noticed something was wrong with his rear glass - I couldn't see them anymore. At a stop, I looked in the car and the rear window was iced up. Those old Freon 12 compressors were dynamite!

 

I have a 2004 F150 Lariat with about 160K on it. The wife has been complaining about the
A/C not cooling off fast enough. Today, it's 100 degrees out and she leaves a client's house. Gets home about 10 minutes later and says it is still hot in the truck. I check, and
she is right. The vent is still blowing in the 70's. So I run a self test on it and it runs thru
and gives a 188. I noticed that the outside recirc door does not cycle during the test. So I put it on auto and run the temp to 60. Still does not close the door. Cycle the A/C off, and the door closes. Now, to my way of thinking, that is just opposite of what it should be doing. The recirc door should close in order to not pull outside air and assist in cooling the interior. Think the control module is defective?

 

Well, I went out and turned the a/c to off and the outside recirculation door closed, Dropped the glovebox door down and unplugged the motor for that door. Took the truck for a drive and still returned to the house in a sweat. Took it over to the shop and had them pull the Freon out, replace the service port schraders and pull a vacuum on the system. Shot it up with 37 oz. Drove home and as I was driving, watched the temp at the a/c vents. Lower 30's. That should keep me cool. Oh, by the way, when I removed the low pressure port access cap, there was a slight hissing noise. Think I found the problem.