Air Conditioning

[Blacktruckdave]

2007 F250 Superduty Supercab 5.4l My AC is blowing warm air. Before I throw a can of coolant in it are there any diagnostics I can run first to make sure its not a heat sensor or something else? I hear it turn on but only warm air blows. Also what should I be putting in it? One of those small cans of coolant from the auto parts store? I don't wanna damage whatever is in it now.
Thank you and happy independence day!

 

[SuperCab]

Does the compressor run? Really need to put gauges on it and not the cheapo gauge that comes with the can of freon.

Seen way too many people make AC problems worse by not understanding how it works.

 

[Big Jim F150]

It's not freon in the newer air conditioning systems, they use the R134a for the refrigerant, both my 2007 Chevy Colorado D.D. And my mom's 2004 Chrysler Town and Country minivan use. So you'll need a can of sealer and lubricant, and also a couple cans of R134a for it and you can get those at any auto parts store. I also agree with Super Cab on using a good quality gauge also available at any auto parts store. You would use your LOW pressure service port for this service, and when you add the refrigerant to charge your system you need to have your engine running, and turn on your air conditioner and set the temperature control as low as it will go. It's that easy, for I had done the system on my 2007 Chevy , and also the system on my mom's 2004 Chrysler. But please read the directions very carefully. The only ones that use freon is the older systems like the one in my 78 F-150 Ranger Lariat. Hopefully you'll find this helpful to you.

 

[SuperCab]

I was using freon as a generic term for refrigerant, but yes, it's no longer the correct verbiage. I think norflurane is actually the proper generic term for 1112 tetrafluoroethane (R-134a)

I would advise against adding any extra oil or other additives to the system as an excess of liquid in the system will reduce performance and can lead to failure of the system

Put gauges on it and see what your current pressures are. If you still have pressure in the system you can probably just add refrigerant and be fine. If your system is completely empty, it should be vacuum evacuated and have dye added to find where it is leaking.

 

[Blacktruckdave]

thank you for the info. I will try it out and see if I have pressure first. Let ya know how I make out.

 

[Blacktruckdave]

Today I started the truck with the hood open and then turned the dial in the cab to Max AC. I heard what I thought was the compressor turn on. When I went to the front of the truck to look, I watched what seemed to be the clutch trying to engage twice...it appeared to spin and make a noise then do nothing. I tried to on and off in the cab but still nothing. I then tried to loosen the nut on the clutch to inspect and the whole unit kept spinning. A sure sign the clutch was not engaged? I also read that the clutch won't engage if not enough coolant in system? How do you add more coolant without the compressor running? (Clutch Problem/Low Coolant/Leak in System?)

 

[SuperCab]

It sounds like the compressor is running intermittently? If so you should be able to add refrigerant. The pressure from the can should be ample to cause the compressor to run.

 

[dustybumpers]

Honestly, just adding coolant to an a/c system is like throwing matches in a can of gas
Please buy a cheap set of gauges, and see if there is coolant in the system, as a bad pressure switch will give you the same symptoms.

Adding coolant to a full system could cause the system to blow up and cause you injury or death
Imagine being blind the rest of your life, because you should have done a repair safely, and properly

 

[SuperCab]

Yes, I should have been more specific. That is a sign that you may just need to charge the system. It still takes gauges to know what's going on.

 

[Blacktruckdave]

Thanks guys. This is exactly why I love this forum. I'm gonna check the pressure today and I will report back.

 

[Sparky83]

without knowing the pressures its hard to diagnose with definitive answers... could be low pressure.. could be bad compressor.. could be bad clutch.. also could be bad switches.. even without the compressor running theres still a minimum pressure reading youll have. on mine the compressor seized and snapped the bolt holding the clutch & pulley to the compressor. clutch parts were gone.. tech said i was lucky the pulley didnt come off going down the road.

 

[Blacktruckdave]

well I made the dummy mistake of not listening here and listening to someone who I thought was a good mechanic. I put a can of 134a(140z) in the system and saw some pressure on the supplied guage...it took the whole can. Compressor kicked on but was running intermittenly more so than before..anyway air was slightly cooler than hot but not cold...drove around a bit and when I got home in the driveway I heard a pop and mist coming out from under the hood. So not I'm driving with the windows down again. Been so long since I knew what air conditioning was....will it ever work now

 

[dustybumpers]

Pop was probably the high pressure blow off on the back of the compressor.
Probably still has a charge, just blew off the excess.
get a cheap set of gauges from Harbor freight, and post a picture what you have.
My lap top is down for repairs where I have my A/c repair pictures, so as soon as I have it repaired, I can post some pictures
My guess, is low pressure switch, but without seeing some pressure readings, it is only a guess

 

[Blacktruckdave]

cool thanks dustybumpers...Its hotter than hades in NJ right now

 

[dustybumpers]

Yeah, I know, I'm in Md. It's been a scorcher here this summer