AC gas refill, pressures

[leholtet]

Hi guys!

Was refilling the ac gas yesterday on a ac machine in a car shop. After it was finished (took about 30 mins) - the high pressure was reading up to 22-23 bar. Is that correct?

[JHZR2]

23 bar = 333 psi. WAAY too high.

What were the conditions outside? Hotter will cause higher pressures, but that is still too high. Was a fan blowing on the car? Was the engine at 1500-2500 RPM?



This is the generic chart based upon some baseline thermodynamics for HFC-134a. In practice when charging by mass, which is the only appropriate way to do it (after properly collecting the refrigerant and vacuuming down to <1000 micron for >30 minutes), Ive found that pressures are usually lower.

Does anyone have access to an FSM to identify the appropriate working pressures for this car or any BMW AC system?

[justanothrone]

To lazy to do conversion but it should be 1.4 lbs if I remember correctly. I just had mine done at BMW last week.