a/c compressor swap

I found out , with u/v dye, my front seal on compressor is leaking. When I change it out, I'm going to replace the drier & orifice too. Should the rest of the system be flushed out, if so with what? Also once everything is put back together, vacuumed & refilled, what kind of readings should I be seeing on my gauges if everythings okay?
Thanks for any help
Doug

If there are excessive particles in the fixed orifice tube, flush the entire system with A/C flush solvent, (available at good auto parts stores), follow the directions on the can. Add the proper amount of the proper oil, keep in mind new compressors are NOT charged with oil. Evacuate the system to 29" for a MINIMUM of one hour, the longer the better. Charge with the proper refrigerant. High side pressure can vary greatly depending on ambient temperature, humidity, cooling system condition, and condenser condition. Typically the clutch cycling switch will turn on the compressor at 42psi and off at 22psi.

The HT6 compressors are pretty famous for belly leaks too. Be sure to check for dye under the compressor. Drier and Otube replacement are a must. To flush or not. You can make that decision when you get things apart. If the old compressor failed to the point that there are tiny shreds of metal in the lines and condenser, you should flush or that new conpressor won't last long.

Get a good set of manifold gauges.

Vacuum with a good pump, not one of those air compressor jobbies. Vacuum to under 1500 microns to get the moisture to boil. Vac for about an hour and then close all gauges and watch for 30 minutes or so to see if it holds the vacuum.

You should see 25-30 on the low side and 220 - 270 on the high side. These are approximate and always relative to ambient air tempature outside. Use PAG150 oil for GM. I'd recommend 3 ounces in the compressor and the rest (approx 8oz) spread into the accumulator and condenser. That way, you won't slug the compressor with a lot of oil all of a sudden.



I found out , with u/v dye, my front seal on compressor is leaking. When I change it out, I'm going to replace the drier & orifice too. Should the rest of the system be flushed out, if so with what? Also once everything is put back together, vacuumed & refilled, what kind of readings should I be seeing on my gauges if everythings okay?
Thanks for any help
Doug