Automotive Air Conditioning Information Forum

Blowout, Flush, replace items that you can not sich as the condenser and accumulator/drier.
Find oil volume spec for system. Find the spec for amount that is supposed to be found in the compressor. Check new compressor for how much was in it when shipped if any. Subtract that from total amount to be in system. Add to dryer and condensor to spread it out, initially. Any that is need to be added to compressor, add to Discharge port so you do not hudr-hydro-Lock again. When adding refrigerant, add in gas state slowly. Do not turn can upside down. Both will cause refrigerant to go in as liquid and can hydro-Lock just like oil.
Engineers of vehicles rough out expected oil loss for each component to be replaced.
Be patient with Tim. He lives in a scorching desert and drives a pickup truck that uses spark plugs.

The trick is to begin with a "dry" system—that is, no oil and no refrigerant. That way, you can start anew by adding the precise amounts of oil and refrigerant according to the manufacturer's specifications—either by oil-balancing the system (discussed at length in the Archives), or by adding all the oil to the compressor, as the factory does.

If "dry" means replacing all of the components, then so be it. But at least you'll know for sure exactly how much oil and refrigerant you've installed into the system *and* that you have all-new components.

These amounts of oil and refrigerant must be precise—'fluid ounces' for the oil, and 'net-weight ounces' for the refrigerant—for the system to run at its best.

Notes: If necessary, don't forget to purge any air from the yellow hose of your Manifold Gauge Set (MGS). This step shouldn't be needed if your yellow hose has a check valve at the vacuum pump end and you proceed directly from the vacuum pump to charging—providing that the vacuum doesn't bleed off, indicating a leak.

Also, don't forget to draw into the system the refrigerant remaining in the hoses of your MGS. Otherwise, you'll end up with somewhat less of a charge than the specifications call for—and hence, the possibility of reduced cooling performance.