95 dodge ram 5.9L engine

hopefully i have found last leak in system. vacuumed system. no leaks. started recharging procedure.

system requires 32 OZ R134a. added refrigerate till low pressure was 55 lbs, high pressue 230 lbs. at that point i had only put 24 OZ of r134a in system.
temperature was about 77 degrees. i stopped adding because i did not want to exceed the recommended pressures.

on a hot day the ac did a fair job of cooling but it did not feel as cool as it should in the cabin.

My question is: Should i continue adding refrigerate til all 32 oz is in the system regardless of the pressure readings or leave it as is?
Has anyone else had this same experience? if so, what did you do?

thanks, tony

 

Your receiver/dryer absorbs a little amount of moisture out if the system. This can displace the refrigerant. Not much, just a little. If your pressure is right, I'd go with it. My '96 is working perfectly but it takes a while to get cool. The early R-134 systems weren't all that good. On Dodge trucks they went with R-134 in '94. Basically, it has a different oil inside and different refrigerant. Not much else. If it's working okay, I'd leave it be. Too high a pressure can blow the seals out of the compressor and other parts of the system.

 

What did you vacuum it down to? When I did mine about 15 years ago I didn't want to leave a can open so I stopped at two cans. When it's hot it takes a bit longer to get it cold. At least that's the way it is today. I'm sure some leaked in 15 years.

 

thanks for the reply. my situation sounds similar to yours.. it does not cool quickly but it is OK. like you i dont plan to add any more refrigerate, plus i may discover there are more (but slower) leaks. over the last year i have replaced evaporator (along with the heater core), liquid line, dryer, orings, compressor, and high port schrader valve.

 

thanks for the reply. i vacuumed for 1 hour down to about 29 hg. held vacuum for 30 minutes. so hopefully all leaks are fixed. like you i stopped after 2 cans because the pressures were high enough. i use cheap ebay pressure gages and vacuum pump but they have performed OK so far.

 

Personally, I shoot a short shot of UV dye into the system. Holding vacuum for 30 minutes is what I look for but the dye will show a leak is you have one.

 

during the diagnosis process, i injected 1/4 oz of dye into the system with the ac compressor running. i used the barrel type borrowed from autozone. i never could observe any dye around a leak point. i found two leaks since applying the dye ( the schrader valve on the high pressure port was leaking and the low pressure switch was leaking where it screwed into the dryer. the soap and bubble method worked. tony

 

you put exactly 32 oz of refrigerant in there. period. you do not charge by pressure! You're OK being off an ounce or two.

charge by weight using digital postal scale (don't trust a 12oz can has 12oz in it).
for amateur a/c repair, I recommend ( ) you just go to a tire shop with a $70 "AC Recharge" special where they can easily vacuum, leak check, and precisely weigh in 32oz with their machine.

 

thanks for the information. enjoyed the videos. tony