95 f150 5.0 automatic with 4x4. I hooked a gauge to the low side
to see if I was low (actually I attached a bottle of refrigerant with a gauge because I thought it would be low). whenever the clutch engages, it builds
pressure until it goes past the max reading on my gauge.
then the clutch disengages and the pressure drops back
down into the green. I had the compressor/orifice/evaporator replaced a year and a half ago
and the mechanic and I are no longer on speaking terms. he
was unsure how much Freon was supposed to be put in, so
he added it until the ac blew cold. it worked well for a couple
months, then got warm. I took it back to him, and he added
more Freon until it worked again. I'm assuming I have a
leak, but he was also not able to find any leaks.

 

Pressure should drop when the a/c compressor is on.

 

maybe since its a cheap "gauge", it's reading backwards?

 

Never saw that before.

 

I'm a dummy. I confused when the clutch was engaging with when it was free spinning. I added a can of Freon and it's working again for now. we'll see how long it holds. Thanks for the help. I double checked when I saw your post and knew I had to be wrong somewhere.

 

It can take more than one can to fully fill it. It's hard to know how much to put in when just adding to an unknown quantity. Most refills have a dye in them that's green so if you have green spray under the hood you def. have a leak, if not I am assuming he didn't put in near enough. It will start blowing cold with just 10-12oz of refrig. but the system holds something like 52oz. If you are frosting up it's low, the condenser should have condensation but not frost.

 

52 ounces is way too much. My conversion van with dual a/c doesn't even use that much.

 

Its more like 38ozs

 

It took about 3 minutes for my ac to kick in today. Also, I am getting some condensation on the condenser once the ac works, but not a whole lot. Is that normal?

 

Condensation? .. Yes. Ice? .. No.