A/C Accumultor Hot?

Got my a/c system back together post rebuild. Vacuum pumped it to clear the system. Has the correct amount of PAG oil new orifice tube and condenser. Started to fill, took about a pound -134. Blowing hot air in the car. Accumulator is warm to the touch. Compressor is cycling. Do I have a bad accumulator? Not enough -134? I don't want to keep filling if I need to purge it again.

You're still low most likely. Add a bit more. Compressor should come on solid and start sucking in the 134A and you will feel the accumulator cool down.

-Mike

Took the full 20oz can. Now its nice and cold.  . Now I just have to remember if that slight hiss by the compressor was always there, or if I have a leak.   

There will be a slight hiss near the compressor, at the orifice tube, usually audible for a short time after the car is shut off. This is normal, resulting from the pressurized liquid squirting through the orifice to the low pressure side.

Any other hisses warrant closer investigation. These compressors are known for "belly leaks" -- the seam between the two casting halves is pretty fragile. It is very important to torque the mounting bolts to spec in stages to prevent stress on this joint. Other possibilities are the o-rings sealing the lines in/out of the compressor, the rubber of the lines themselves, the crimp joints and the compressor shaft seal. Did you add UV dye or have access to an electronic leak detector?

As you already discovered, a warm accumulator is a sign of undercharging. When the system is properly charged, the evaporator inlet line and the outlet line up to and including the accumulator should be approximately equally cold. The accumulator allows any residual liquid to evaporate off, so if the line out of the accumulator is also cold, you are probably overcharged. Weighing the charge is more precise, but the line temps are a good "rule of thumb" guide.

Yeah, its a hiss for about 3-5 seconds after I shut the car off.

Cadet57 wrote:

Yeah, its a hiss for about 3-5 seconds after I shut the car off.

That's probably just the normal sound of the pressure equalizing then. If it was a leak big enough to be heard, your system would be empty in short order.