ken72

I was trying see if I need to add some 134a and this stupid psi guage I cant work out. I do it as I believe it says and I even watch the video. I hook up the guage and it reads 0. Turn on the jeep and then as soon as I open the valve to release the 134a it shoots to like 70psi. Now the way I understand it this Effing thing is supposed to read the PSI with the valve closed and as I open the valve and release the 134a it should slowly increase with the pressure of the condensor until it reaches the range of ambiant temp. So why does it shoot up to 70psi as soon as I release the valve? The only reason I even thought to add any is because 1. its getting close to warm weather and I dont know what the PO did prior and 2. when I turn the air on, the condensor sounds like it keeps kicking on and off every few seconds.

caged

you have to be careful when recharging the system, you could really screw things up big time.

the compressor is supposed to kick in and out when on any a/c setting as well as defrost.

91familyxj

X2 your compressor kicks in and out not the condensor. You also cant charge the syem properly untill it is warm outside like 80ish. I dont know what it is there. Also depending on if you have the freon upside down and bloweing in liquid or rightside up and pulling in vapor. That will determine how fast the pressure builds up.

cujoe

Hey neighbor. If you need some help with your ac i would be glad to give you a hand. I have some experience with automotive ac systems and I have a professional set of ac gauges. Im not sure what type of gauge you have but if you have one of those cheap gauges they dont always work right all the time. Does your ac work at all now?

ken72

Hey Cujoe, first post here? Thanks and welcome! Yea my ac is working and blowing cold, but i havent really ran it for any length. I just really wanted to see if it needed any and I was told that if it keeps clicking on and off its low and needs charged. Maybe not.... I dont know.

cujoe

Yeah alot of times if it is a little low the compressor will cut off and on frequently.

ken72

Good deal.... I will give you a shout.... it would be nice to know some other XJ owners. This was at the bottom of my list of things right now. I have a leaky rear main seal and valve cover I need to get fixed. I just need to drag my lazy but under under the rig and get it done.

BTW... I saw the pictures of your Classic... nice looking ride.

cujoe

Yeah, I have a few things that need to be done to my jeep also. I just bought it back in October after I lost my other car in a near fatal car accident I had back in July. But overall the Cherokee is in good shap.

SHO_91

70 psi sounds a bit high for the lo-pressure port. My gauge reads 40 to 50 psi in the green (= good) area. And, same here, I have to open the valve to get a reading at all. It's definitely not accurate, mine sits at 5 psi when I disconnect the fitting. I'd probably do a complete evacuate, and then re-charge (with PAG oil). If it still reads high, and kicks on and off, it could be plugged somewhere (dryer/accumulator, orifice tube).

ken72

Yea, I suppose its possible the PO over charged it. Could that explain the steam I get from under the hood when I have the cold air defrost on when it rained last time? I thought it was just water on the radiator but it quit as soon as I turned the defrost off.