A/c issues.

[VetteMed]

Those air-compressor powered vacuum devices really don't draw the level of vacuum that is ideal to be able to rapidly boil off any residual moisture. Better off with a used Robinair or similar on ebay.

Originally Posted by sammy

i have converted both my zs to 134. i bought a new accumulator and changed out all the o rings to new ones . i evacuated the system for 2 hrs to get all the 12 oil out . then installed the new accumulator put 2 oz of oil in the compressor 2 ozin the accumulator . then evacuated the system for an hr . closed off both valves to see that it held the vacuum. if it did then i filled with 2lbs of 134 that also had oil in the can . it can be a little fun trying to get the compressor to not kick off and stop the fill at first . but i just stopped the car disconnected the battery and started the car again(usually) only had to do this twice . i did the 90 5 yrs ago and its still cooling great .the 92 did this year and doing great also . you can get a air compressor operated evact unit from harbor freight tools for about 50 bucks which saves having to pay to have it evacuated by a shop . its really not a hard job to do just take your time oil up the o rings in the 134 oil before installing and clean all the threads of the connection points in the system before putting it back together . hope this helps