How do I do an A/C system pressure check on my car?

Answer by  McCheese (1248)

Go to a Jeep dealer and ask to use the Jeep Pressure Monitor. It's a small tool that they insert into the evaporator. This will tell you if you have fluid left or if you need a freon refill. If the monitor detects no freon, chances are that you have a leak and there will be zero pressure.

Answer by  worker2539 (68)

Buy a gauge from the local parts store, and place it on the low pressure port. I would recommend getting a manual or going online and finding a vehicle-specific picture telling you which is the low pressure port and which is the high side. If you put the gauge on the high pressure side, bad things can happen.

Answer by  Raf (146)

First you must purchase a meter. The large connection end is the high pressure side and the small connection end is the low pressure side. Locate the A/C lines and connect accordingly. The connections on the lines may have a small cap. Simply twist them off, connect the ends, and the metering device will say if your pressure is correct.

Answer by  vishnuprasathpa (9)

Easiest way is with stuff they sell at auto parts stores, you can get it in kit, with the light, dye, and glases, its seems complicated but its fairly easy. Just follow instructions on It is most likley the high or low side port and that is an easy fix, it looks like the core from a tire's valve stem,

Answer by  Pat57 (138)

The easiest way to do an A/C pressure check on your Jeep is to go to the auto parts store and buy a recharge kit that has a gauge on it aslong as a leak detector.

Answer by  Doug77 (1433)

Connect the low-side/blue to the large connector and the high-side/red to the smaller. Engine running; the low-side is 28-30 psi while the high-side will be ambient temperature +/- 100.

Answer by  japratt (1687)

To be able to check the system pressure on your car you are going to need to get under the hood first. Then you can check the AC by the AC section.