Something is going on with the A/C in my truck. I first noticed it last summer but it is worse now. Sometimes it just randomly turns off. Sometimes it will come back on after I turn the engine off such as when I got to a store. Other times it will randomly come back on after driving 5 to 15 minutes or more.

The air is plenty cold when it does work. The length of time it blows cold air varies anywhere from 5 minutes to one hour or more. I can also hear a "rattling" noise as the compressor is running. I can only hear it when I'm at stopped since my tires and exhaust make more noise. That noise only seems to happen after I've been driving the truck for 10 to 15 minutes or more though. I did take a look at the A/C clutch with it running. It stayed engaged the few minutes I watch it. The only thing I noticed is that there might be some wobble in it.

The only other thing that seems to make a difference is heat. The hotter it gets, the worse the problem gets.

Any idea what the possible problem could be? I'm going to making a trip to South Carolina about a month from now. It would be nice to have this fixed before then.

 

You need a new clutch hub, at a minimum. Motorcraft part number YB-3020.

Remove serpentine belt.

Remove the clutch hub. It will probably come off in pieces.

Inspect the Clutch pulley for bad bearings (rough operation, wobble, etc). If pulley fails inspection, replace with Motorcraft YB-522.

If you need both, Rockauto is around $95 with 5% discount code.

Mine did something similar a couple of winters ago. I ignored it too long and the pulley bearings eventually grenaded. Locked the pulley so tight the started couldn't crank the engine. Got a ride home from the local AAA tow truck driver with the truck on the flatbed.

 

Thanks. Any idea how long it takes to replace those items if everything comes off easily? What about special tools?

Are these are the exact parts you mentioned? I just want to make sure since I have recieved wrong parts even though the part number was correct.

http://www.oreillyauto.com/site/c/de...2637&ppt=C0354

http://www.oreillyauto.com/site/c/de...2640&ppt=C0354

 

you might also check your fan clutch i have had a few f150s in the shop this summer with airflow issues 2 needed new fan clutches the third needed the condenser cleaned out it was caked with dirt and dust so bad no air could pass thru the fins.

 

The fan clutch is a good possibility but it won't help in my case. I installed a flex fan last halloween. I was having this problem before that so that shouldn't be the problem. I do appreciate the help though. I'll take a look at the condenser.

 

Those are the correct parts.

Only "special" tool is a set of large snap-ring pliers with 90 degree tips if you need to replace the pulley. Other than that, it's just a 10mm wrench and a couple of flat tip screwdrivers.

I did mine in way less than an hour from underneath on my back. If you need only the hub, it's 10 minutes.

 

Okay. I have the parts but I won't be able to do the work for a while. I was doing some stuff a few days ago and the A/C didn't come on again. Luckily I was still in a parking lot so I decided to see if the compressor was engaged. The compressor wasn't engaged so it isn't getting power every once in a while for some reason.

I'm going to check for power at the control and the two switches. Let's say the charge is fine and I find an issue at one of the switches on the system. Is it possible to change either switch out without draining the freon?

Both switches are getting power so I assume the A/C pressure switch is fine along. That is the switch on the line near the washer fluid reservoir which I assume is the high pressure side of the system. I changed the compressor cutoff switch after finally finding it was safe to change with the system charged. That didn't do anything. I have one of those kits to fill/recharge the system that came with a guage. Green being low (0-25 PSI), blue being normal (25 - 45 PSI), yellow being an alert (45 - 65 PSI), and red being a warning (65+ PSI). It was in the red zone at about 100 PSI and the system wasn't even running. It has been at least four hours since I drove the truck and it is about 80 outside.

 

Install the mechanical parts before screwing with anything else.

Do not mess with the charge level until the known mechanical fault is corrected. Static pressures over 100 psi are completely normal.

 

Guys, I'm having the same problem with intermittent A/C. Really cold then warm. Freon is good. I'm not an HVAC guy and really do not have anyone around that I know I can trust. It sounds like there are several issues I could have so with that said what would you check first and then what order after that?

Thanks

 

Check the clutch gap. If gap is excessive, perform a shimectomy.

 

There appears to be a leak somewhere now. I've put in some freon that has the UV dye. I can't find the leak though.

 

x2. this fixed my intermittent A/C issue...

 

After doing some more reading I think the evaporator might be the source of the leak. I think I'll wait until winter if that is the case. I don't feel like spend ~12 hours taking the dash apart and putting it back together in the summer heat. Something I noticed is that the whole box containing the heater and evap cores was covered in condensation one day when the A/C worked.

Wouldn't I smell something or feel sick from breathing the freon though?

 

I'm reviving this old thread because my a/c is doing something similar. Pulley wabling, noises like bearings grinding, clutch seems to be working fine. Infact, with a/c on the noises decrease quite a bit and the pulley stablizes with clutch engaged. Should I just replace the pulley, or both the clutch and pulley? Are there any other parts I should check/replace? Thanks for any input!

 

What part of post # 2 didn't you read?