GregB

1995 Ford F150 AC evacuated , installed 2lb 4 oz of R134a ( have legit scale ) cools great when the low pressure switch on the side of the accumulator is jumped. Is that just a safety low refrigerant switch or is it needed for normal operation ?
Can I leave the jumper in it and drive a few days without problems IF it does not leak and get low on R13a while I figure out if there are other problems ?
Also my high side valve , when I tried to take off the red hose is leaking... I have the legit Schraeder valve replacement tools.. but I do not think they will reach through the aluminum R134a fitting to extract them. Thanks, GB

Steve83

The low switch is what makes the clutch cycle when the air temperature gets so low that the evaporator might freeze. Jumping it could result in a block of ice around the evaporator core, blocking all airflow. It could also result in the compressor sucking in outside air if there's a refrigerant leak. The switch is cheap & common to buy new, and even-cheaper & -more-common at JYs. Just make sure you get the yellow/orange R134a switch.


(phone app link)

The factory service ports do NOT contain Schrader valves - they contain rubber *****, which are easy to cut with inexpensive gauges. If yours is a factory port, you'll have to buy a new one.

Refrigerant service is more complicated than it seems. If you're not trained for it, you should pay a pro to do it right. Read all the captions in this album:


(phone app link)

GregB

Twenty years of dealing the automotive AC stuff and this is the first time I have ever seen such a bad design for an AC ' valve' . FORD has a fix which puts a normal Schraeder valve into that space. It is
F3AZ-19E762-A
less than $20
the old aluminum fitting screws off ( after evacuation ) and this one simply screws on. I found this youtube video showing it.