Refrigerant Check - R-12

The following procedure can be used to quickly determine whether or not the A/C system has the proper charge of Refrigerant-12 (providing ambient temperature is above 22°C (70°F).This check can be made in a matter of minutes, simplifying system diagnosis by pinpointing the problem to the amount of R-12 charge in the system or by eliminating low charge possibility from the over-all checkout.

1. Start engine and allow to warm up.
2. Hood and body doors open.
3. Set at 60°F and Auto.
4. "Hand-Feel" temperature of evaporator inlet pipe after orifice, and accumulator surface,with compressor engaged.

A. BOTH SAME TEMPERATURE AND BOTH SAME DEGREE COOLER THAN AMBIENT--Proper condition. Refer to ECC Functional Test.
B. INLET PIPE COOLER than accumulator surface low refrigerant charge.
^ Add slight amounts 120ml (1/4 lbs.) of R-12 refrigerant until both feel the same temperature.Allow stabilization time between additions.
^ Then add 420ml (0.88 lbs.) 1 can additional R-12 refrigerant. (The 420ml/14 fl.oz. disposable can of R-12 refrigerant is the equivalent to 0.88 lbs.)
C. INLET PIPE HAS FROST ACCUMULATION-- Accumulator surface warmer; proceed as in Step B above.