Expert: Candido Figueroa - 2/17/2010

Question
Hi, in a 1999 Ford F250 v10 7.3L, what should be the
reading in the preasure gauge when the A/C System
is charged properly? psi, C, F, Kpa?

Answer
HI CHARLIE

In psi the low should be between 25 and 45.  The high should be between 175 and 275.  This range is due to the ambient temperature.  If your climate is cold then you will be on the low side of the spectrum.  For instance if your ambient temp. is 45 degrees F. then your pressure can go as low as 20 psi and the compressor will cycle on and off.  The best way to charge is with a charging station.  If can be electronic or just a charging cylinder.  your vehicle takes 32 oz. of refrigerant.