Shop manual says:
- Approximately 3,120 kPa (31.8 kg/cm2, 452 psi) or more (Engine speed is 1,500 rpm or more.)
- Approximately 2,740 kPa (27.9 kg/cm2, 397 psi) or more (Engine speed is less than 1,500 rpm.)
You can't just say "double the ambient" because the P/T curve of R-134a is non-linear, rather it is somewhat parabolic in nature. Pressure increases faster as temperature goes up.
The factory shop manual calls for a high side pressure of 185-227 psi at 104F ambient. This indicates a condensing temperature of 125F-140F, so the factory is saying your effective condensing temperature is going to be ~25 to 40F over ambient. 130F + 25 to 40F comes out to 155 to 170F which works out to 281psi to 340psi.
Systems should not be charged by pressure. They should be charged by refrigerant weight. Do not decrease the charge below the factory spec, if you do, you'll get poor oil return to the compressor, and eventually it'll trash it.
Quote:
Originally Posted by hindi1973
jm1fd, wht pressure do u think the compressor will start cutting off if its too high or too low on the high or low side ?because from my knowldge the low should be 32 to 40 max and high side should be doublt the ambient temp the car is in so if its at 130f , the high side should be 260 to 300 max , but the qustion is wht pressures should we avoid leavin the car in
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