Let me know if I did this right (2001 pontiac GP 3.8 NA GT)
had leak in system, determine it was either the liquid line or suction line underneath the brake booster area, could hear hissing from that area.
Did the do nothing option for a while then got my wife prego and she said either fix the AC or we buy a new car with one that works.
Evac'd the system.
Removed old liquid line, suction line and replaced with the drier/accumulator and replaced all orings I touched and used NAPA syl-glyde for lube of orings.
Put nitrogen 100 psi test on system and soaped all fittings, no bubbles and pressure held steady for 2 hours.
Pulled deep vacuum with robinair 5 cfm 2 stage for 1 hour and system went to -30" HG within 10-15 minutes. isolated system by closing gauge knobs and turning off pump.
Left gauges on over 14 hour time frame and went from -30" HG to -29" HG, felt the system was tight enough to fill.
Read label on driver shock tower (R-134a with dye, factory charged to 2.25lbs). Bought 3 cans of R134a, First can was 11oz of R134a, 1 oz of oil and .5 oz of drying agent. Second can was 11oz R134a with 1 oz of dye. Third can was striaght 12 oz of R134a.
With system still in -30" HG I hooked up the first can and purged my charge line, then slowly opened the low side on the manifold. Car was running (idle) with AC on max with fan speed on #3 and all doors open. Followed directions on can and after about 5 minutes the compressor cycled on and sounded nice and smooth. Then added second can and so on to third can. Took almost an hour to add all the refrigerant, I went slowly by heating cans in engine bay and warming with hands to help fill system but every once and a while I had to tilt horizontal to slug refrigerant in, did it carefully though by watching my sight glass on the manifold gauge set.
Was pretty cool outside (61F ambient) and center vent was dumping a consistent 35-38F degree air. drove for 20 miles and keep digital thermometer and never hesitated. Felt the liquid line after condensor and was hot and after orfice tube was cold.
Let the car sit in the sun for a while with the windows up (increase load on evaporator (dry bulb only no humidity outside)) and turned on again. Low side pressure was between 25-30 PSI with the high side steady at 100 psi and the center vent 35F. Ambient temp was 62F ish with little to no humidity and interior car temp was around 80 ish.
Waited a couple hours and pulled it back in the garage and inspected all lines and components with black light and found no traces of UV dye (even checked the Evap drain elbow and clean)
Anywas - since I tried doing this DIY, how did I do? what mistakes did I make, let me know.
My plan is to wait until we get a good 85F degree day and hook up the gauges again and measure the center vent temp but it has been pretty chilly here in MN.
Tools used -
Robinair 5 cfm 2 stage vacuum pump - bought
CPS MA1234 working mans gauges for R134a - bought
standard tools for removal and replace
Nitrogen tank (had from snowmobile shock repair work)
black light UV detection - bought.
