What could be wrong if my Ford F150 ac has low side pressure?

Answer by  BigE (28)

Your F150 may have low AC pressure due to a hole or leak in the compressor return tube. Verify a leak using a hand mirror placed below the return valve and have an assistant step on the accelerator intermittently to see if refrigerant fogs the mirror. If test indicates a leak, please see your local dealer for the repair.

Answer by  McCheese (1248)

If the AC has low side pressure, you're going to have to buy sealant fluid for the AC hoses. Chances are, you have a small hole causing low pressure.

Answer by  MikeG (1650)

This is most likely cause by a leaking vacuum line, it could also have to do with an EGR valve malfunction or another emissions part on the vehicle. Have someone run diagnostics on it.

Answer by  cab1882008 (45)

You might have a clogged orifice tube, which is the most common problem and should be replaced regularly. It may also be a weak a/c compressor, or a partial blockage in one of the lines, maybe even in the condensor.

Answer by  scwriter007 (254)

Vehicle AC systems have both a high-pressure side and a low-pressure side. If you checked the high-pressure side and got a low pressure reading then you have a leak.

Answer by  Doug77 (1433)

I'm not sure what's meant by this question. The AC consists of a High-side and a Low-side in which the refrigerant changes from gas to liquid as it absorbs moisture and cools the air. With the engine running the Low-side should read between 28-33psi. Anything lower will mean the system is low. High-side reads ambient temperature plus 100 degrees.

Answer by  andrealmeida6 (7)

My F150 might have low A/C pressure because there could be some kind of hole or leak in the compressor return tube. I could verify a leak using a hand mirror placed below the return valve and have an assistant step on the accelerator intermittently to see if refrigerant fogs the mirror. If test indicates a leak, problem found.

Answer by  les59 (852)

There maybe a blockage in the venting system of your vehicle. The best thing to do in this situation is take it to a certified Vehicle HVAC facility to have your cooling system checked out. They can do all the tests that you need to find out where the blockage is and fix it.

Answer by  billyb (562)

you need to check and see if you have a blockage in the cooling system. you may have too much freon or not enough.