jarrettp

Just replaced a blown high pressure hose and vacuum bled my system, I recharged it but it was too high at first so the A/C compressor clutch was cycling on and off rapidly at ~80psi low pressure side. I bleed it down to about 55psi low pressure side, 275psi high pressure side and it's much better, but I'm worried this might still be too high pressure? I see people saying anywhere from 30-60psi low pressure side is good, but high pressure I have no clue.

Ambient temp of ~110* while doing this btw. Bone stock 94 D15Z1 with factory R134a system

sumdewd

Was this 275 psi at idle or at 1500rpm, and was it cooling fine? 110 ambient is kind of in the ballpark for a 275 psi high side, but you should never charge based on pressures alone. Humidity, ambient temperature, charge level, engine speed, compressor condition, blower setting, condenser and fan condition all affect pressures. Pulling the wrong level of vacuum will also make pressures skyrocket.

These systems are so small where even an ounce or two can be more than 10% under or overcharged. And did you use an actual electric vacuum pump or one of those little venturi pump things that hook up to the compressor?

The only way to properly charge these systems to isolate any other variable is to charge by weight with a refrigerant cylinder and a scale. The 94 uses 19 ounces which isn't even two of those little Walmart cans, so it'd be really tough to just guess the amount.