The R134 appears to have exited the AC system over the winter. I tried to put in a can today but the compressor won’t start, likely because the pressure is too low. Is there a way to by-pass the circuit and get the compressor running to get the R134 into the sytem?
93 XJ6 VDP
Add the first can with the top facing down. This puts it into the system in
liquid form. Only add enough this way until the compressor will start. Add
the remainder with the can upright(gasous form.)
Jim Moore(88 XJ40)
Thanks Jim but that’s what I tried and it didn’t work. Any other ideas?
I recommend that you NOT add R134a from an upside down can to the suction
port of your system. The compressor cannot pump a liquid – only gas. You
should be able to get enough pressure from an upright R134a can to trigger a
low pressure switch, if you keep the can of R134a warm. At 70 degrees F the
vapor pressure of R134a is around 70 PSI.
There are several other AC designs in various cars that have accumulators on
the suction side of the system. If the low pressure service port is
upstream of an accumulator, it may be OK to add liquid refrigerant.
You could pull the connector off the back of the compressor
and short it.
That is what I did while pumping out the r12.
I put my jug of r12 in the freezer, got the car full hot,
hooked um my gauges and the tank, shorted the low pressure
switch, and ran the compressor till most of the gas was out.
Do NOT ever put liquid into the system.
Best way to break your valves in the compressor.
I am not sure what the switch pressure is set at, and some cars,
or all cars have a switch that melts and needs to be replaced.
Heating up the tank of gas may help,DONT put it in the oven!
Let it warm up in the sun or something moderate…
The R134 appears to have exited the AC system over the
winter. I tried to put in a can today but the compressor
won’t start, likely because the pressure is too low. Is
there a way to by-pass the circuit and get the compressor
running to get the R134 into the sytem?
93 XJ6 VDP
My compressor doesn’t have any connectors on hte back, just the hose ports and a hex nut with a hole in the center. What does the low pressure switch look like?
Where is it usually located? Is there a reset of some sort to get it running long enough to get some gas in?