Automotive Air Conditioning Information Forum (Archives)

polilrichkid on Fri July 27, 2012 1:57 PM

Year: 1970
Make: Ford
Model: F250
Engine Size: 360
Refrigerant Type: R12
Ambient Temp: 80
Pressure Low: ?
Pressure High: ?
Country of Origin: United States

Would someone tell how to work the a/c valves on the compressor in order to check pressures and add freon. It has been a long time since I worked on this type and my memory is not as good as it once was.

Thanks, Rich

-------------------------
po lil rich kid

TRB on Fri July 27, 2012 4:47 PM

You have the York Compressor on this vehicle? If so you will need to open the valves (valves on compressor) after attaching your gauges.

-------------------------

mk378 on Fri July 27, 2012 6:45 PM

Yes connect gauges, turn valves about 1.5 turns clockwise to open the service ports.

polilrichkid on Fri July 27, 2012 9:27 PM

OK. Now if when I do this and the suction side is 70lbs, there is an issue correct? I am trying to figure this out. The compressor kicks on when the a/c is turned on. Now a days, that means that there must be freon present. Then were there any safety switches? I didn't see any under the hood. I assumed there was freon in it, at least some. But I may be wrong.
I know in the past that the low side went up as the freon went into the system, them came down below 30 approx.. But when adding the freon the low side went up and up, so I quit, for now. I wanted to get some answers. This is an original truck with factory add on air. The truck only has 14000 mile on it, from new. Just wanted to add to it to cool it down inside, you know. Hope someone will help me out some more. I haven't turned a wrench in 30 years or so. I have had lots of time to forget. Thank you for the help.

-------------------------
po lil rich kid

fireguywtc on Sat July 28, 2012 2:29 PM

Its my understanding that these model of pickups have no safety switches in the system at all, only a thermostatic switch. This is for factory A/C setups, dealer and aftermarket addon systems could be different. My 70's A/C leaked out because I left one of the valves cracked open and the compressor was running with no refrigerant in it. Made a funny clicking sound when it was running but I didn't run it long before I figured out something was wrong.

Did you take any readings on the system when it was running or only while it was off?

-------------------------
1970 Ford F250 4x4
2007 Ford F350

polilrichkid on Sat July 28, 2012 3:36 PM

Hooked up gauges to suction line only (while the a/c was on) and it was reading 70-80 lbs. Should be reading under 30lbs. I probably should replace drier and expansion valve and vacuum it down then charge it. I added some, not a lot of R12, the gauge went higher and higher. What are your thoughts? Thanks for your input.

Rich

-------------------------
po lil rich kid

Edited: Sun July 29, 2012 at 2:36 PM by polilrichkid