Hey guys I just retrofitted my firebird ac and I put (2) 12oz. cans of 134a. One of the cans had leak sealer and system cleaner in it and the other was just plain old 134a. Should I put anymore cans into it. I have an ac pressure gauge but it still reads low.
AC seems to be cooling and feels good right now!
Should I add another can???

Thanks guys!


Knight75

 

Number 1 rule of AC work...If it ain't broke, don't fix it...


that said, these retrofits are more of an art than an exact science. Ideally, these cars can use about 2 1/2 cans. 3 whole cans would have you slightly overcharged, and will deminish your cooling capacity.

2 cans is slightly undercharged, but many r134 conversions cool better with a slight undercharge.

The most common problem with an undercharged system is compressor overheating. Your compressor is cooled by the returning refrigerant line. With the engine idling, ac on max, and blower on high, feel the suction line (the one coming from the accumulator to the compressor) at the compressor. It should be good and cold. As long as it feels good and cold, your system has sufficient charge to keep the compressor properly cooled. Beyond that, charge weight is determined by system performance.

Since you have already stated that your cooling performance is satisfactory, if your return line is cold, I would leave everything alone, and call it good enough.