Blogs Car Info Our Show Deals Mechanics Files Vehicle Donation

Problems with A/C

I have a 2000 GMC Sierra 1500, 350 V-8, 2WD. It has been fully charged with refrigerant, but compressor is still starting and stopping every 10 seconds or so. I’ve been told to replace the pressure cutoff switch that is on the pipe connecting the evaporator to the accummulator. Does the regrigerant have to be bled in order to do this safely?

No low pressure cut-off switches can be replaced without loosing the refridgerant

Sorry, I didn’t quite understand your reply. Are you saying it’s OK to replace the switch without purging the refrigerant?

Sorry, I should have used a comma. Iam saying yes it is ok to replace the switch without purging the refridgerant. I thought this switch was directly on the accumulator.

Funny how something as small as a comma can really screw things up. The guy at the parts store told me I could do it with no problem, but when I started to unscrew it, some white liquid came bubbling out. I started to freak out, tightened it back up and decided to wait until I got some additional information.
Thanks again

The fact that the switch is a ‘pressure’ switch means that it is exposed to system pressure. A qualified person might be able to trap the charge in part of the system away from the ‘pressure’ switch but that person should be a qualified HVAC technician IMHO.

Yes, a little Freon will escape. Unscrew the old one quickly to minimize the amount. There is a valve that will close as you remove the switch. It’s just like the valve on the tire stem.