by Mercho » Sun Sep 30, 2007 2:18 pm
A/C systems are sealed systems, not buyers of refrigertant. If the refrigerant is low, the system needs checked for leaks. it's useless to try filling a system that leaks.
Regardless of the car, recharging is the same for a car as a truck as a farm tractor with air conditioning. Charge from the low pressure side with the a/c set to max and the blower fan to high. The low pressure side is the fat hose and the charge port should be in the low pressure side, on occasion near the compressor on occasion nearer the evaporator case. The engine should be at idle speed and the clutch should engage shortly after starting adding the R134A.
Make certain you're adding it to the low side or you may be able to blow up the can in your hands.. When the can is not "cold" to the touch it should be empty & prepared for a second can. Read the lable in the engine area or get a service manual for the truck and compute how many cans to add to fill the system. I'd also add a can of dye to trace any leaks that can be small for a fix when found.
Always if you aren't familar with the terms I used you need a pro as you may be severly injured or asphixated if you don't have the expertise and knowledge to do this task. on occasion is is best to hire the pro and you go and do what you do best. The over all cost will be lower if for no other reason than it'll not must be done over and undo what you did wrong plus that cost.
Under no situation mix R12 with R134A, they aren't matched and the gauge hook ups are different although I'm sure somebody can find a way to defeat the system's satefy features .
If you're converting from R12 to another type refrigerant I strongly propose converting to R134A only, as propane type replacements for "freon" are greatly flameable and dangerous to an unsuspecting tech. more, if a leak is into the interior where people are, it may because a flash fire inside and hurt or worse the occupants.
US vehicles started in 1993 using R134A, by 1995 all US certified vehicles A/C systems were filled with R134A.
You should also check to verify that there isn't another problem keeping the clutch from engaging, as there are low pressure switches that go bad, the clutch/magnet may be be bad, wiring, a/c switch, or some number of other things. Again a good honest tech will save you money and time which is the greatest cost.