High Pressure switch explosion

GUNNERGARIDEL

MEMBER
2002 GMC SIERRA
6.0L
V8
2WD
AUTOMATIC
319,000 MILES

Greetings:

I watched your YouTube video on how to vacuum down and recharge the system, but things did not go according to your video. :(

I have the truck listed above 1500hd w/6 liter. I was in the process of replacing my compressor which was bad. I installed a new compressor, new condenser, new accumulator drier, replaced the low- and high-pressure switches on the accumulator and the back of the compressor. I followed your video to the letter, including not opening the high-side manifold gauge. I ran vacuum tests for 30 minutes, waited 10 minutes, and perfect -- no leaks!

So, I proceeded to load Freon, and the same thing happened the last two days: within 30 seconds after beginning to add Freon, the high-pressure switch on the back of the compressor blew out! I assumed it happened yesterday because I had not properly installed the split ring to hold the high-pressure switch in place, so I carefully checked to ensure the split ring was installed properly.

Today, the same thing happened again -- within 30 seconds there was a loud hissing, then a 'pop', and the high-pressure switch had blown out again. Can you tell me why this happened, and what I can do to correct this and ensure it does not happen again?

Dudley Garidel
Baton Rouge, LA
Semper Fidelis! CWO4 USMCR [Ret] 17 February 1969 - 1 August 2004

3 Replies

STEVE W.

MECHANIC
13,443 POSTS

Okay, so, you pulled a vacuum and had no leaks, Which way are you adding the R134A? Can needs to be used with the tap and hose up, if you tip it over you get liquid into the system and liquid doesn't compress and can damage the compressor and blow out the high-pressure parts. You want to charge with vapor only and let the system work to fill itself. If it is warm out it can take a bit and you may need to put the cans in a hot water bath to get it to flow in faster.