COMPRESSOR OIL CHECKING - GENERAL PROCEDURES
| CAUTION | When discharging air conditioning system, use only approved refrigerant recovery/recycling equipment. Make every attempt to avoid discharging refrigerant into the atmosphere. |
Some models have compressor-mounted service valves that allow oil checking by isolating the compressor. On all others, system must be discharged and compressor may need to be removed to check oil. After oil level is checked and adjusted, A/C system must be evacuated and recharged.
ISOLATING COMPRESSOR
- Connect manifold gauge set to service valves on compressor. Close both gauge valves. Open both service valves to the mid-position.
- Start engine and operate air conditioning. Turn suction service valve slowly clockwise toward front-seated position. When suction pressure is reduced to zero or less, stop engine and quickly close suction service valve (front-seated).
- Front-seat the discharge valve. Loosen oil check plug slowly to release any internal pressure. Service valves can now be removed from compressor and compressor removed from vehicle (if necessary). Purge compressor after servicing.
PURGING COMPRESSOR
- Remove gauge set and place caps on service valve ports. Back-seat the suction service valve to allow refrigerant to enter compressor.
- Loosen discharge port valve slightly. Loosen valve port cap to allow refrigerant to force out air from compressor. Back-seat the discharge valve and tighten the port cap. Compressor is ready for service.
REFRIGERATION OIL
Only new, pure, moisture-free refrigeration oil should be used in the air conditioning system. This oil is highly refined and dehydrated (moisture content less than 10 parts per million). Refrigeration oil container must be kept tightly closed at all times when not in use, or moisture will be absorbed from the air and introduced into the refrigeration system.
HARRISON A-6, 6-CYLINDER COMPRESSOR OIL CHECKING
Note. Harrison Compressors, built by the Harrison Radiator Division of General Motors, may have been referred to in the past as Frigidaire, General Motors or Delco-Air Compressors.
The system is fully charged with 10 ounces of refrigeration oil. It will not normally require addition of oil unless definite oil loss has occurred due to ruptured line, leaking compressor seal, replacement of system component, compressor overhaul, or vehicle collision.
NO SIGN OF OIL LEAKAGE
- Remove compressor. Drain and measure oil. When replacing compressor, replace the amount drained plus one ounce. If the amount drained from compressor is over 8 ounces, system must be flushed. Replace accumulator. Install compressor filled with 10 ounces total.
- If evaporator is replaced, add 3 ounces to the new evaporator. If condenser is replaced, add one ounce. If accumulator is replaced, drain old accumulator and measure oil. Add the same amount, plus 2 ounces, to the new accumulator.
SIGNS OF EXCESSIVE OIL LEAK
- Remove compressor and accumulator. Drain and measure total oil from both components. If less than 6 ounces, add 6 ounces to the system. If more than 6 but less than 8 ounces, add the amount drained. If a new accumulator is installed, add 2 additional ounces to compensate for oil retained in the desiccant.
- If amount drained is more than 8 ounces, flush system. Replace accumulator. Install compressor filled with 10 ounces total.
Note. If oil drained contains metal chips or other foreign material, flush system. Replace expansion tube, accumulator, and other components as necessary.
HARRISON DA-V5, 5-CYLINDER COMPRESSOR OIL CHECKING
Note. Harrison Compressors, built by the Harrison Radiator Division of General Motors, may have been referred to in the past as Frigidaire, General Motors or Delco-Air Compressors.
- When a DA V5 compressor is removed from the vehicle for servicing, the amount of oil remaining in the compressor should be drained and measured. This oil should then be discarded and new refrigerant oil added. NOTE: Drain oil from the oil drain plug open to insure complete draining of oil from the compressor.
- The compressor has a unique lubrication system. The crankcase-suction bleed is routed through the rotating swashplate for lubrication of the swashplate bearing. The rotation acts as an oil separator, which removes some of the oil from the crankcase-suction bleed, re-routing it to the crankcase where it can lubricate the compressor mechanism.
- Up to 4 ounces of oil can collect in the crankcase. All replacement compressors will be shipped from the factory with 8 ounces of oil in the crankcase. The oil must be drained from the oil drain plug opening and retained. Replace the oil in the same quantity as previously drained from the old compressor.
Note. If a new accumulator must be added to the DA V5 system, add an additional 2 ounces of oil to the compressor to compensate for that retained by the original accumulator desiccant.
HARRISON DA-6, 6-CYLINDER COMPRESSOR OIL CHECKING
Note. Harrison Compressors, built by the Harrison Radiator Division of General Motors, may have been referred to in the past as Frigidaire, General Motors or Delco-Air Compressors.
Systems with this compressor are fully charged with 8 ounces of refrigeration oil. Due to the compressor's design (without oil sump), it does not have to be removed for oil measurement. Note the following situations for checking and adding oil with this system
NO SIGN OF EXCESSIVE OIL LEAK
- If compressor is replaced, remove, drain and measure oil. Replace with same amount of new oil plus one ounce. If evaporator is replaced, add 3 ounces of new oil. If condenser is replaced, add one ounce of new oil.
- If accumulator is to be replaced, remove, drain oil, and measure. Replace with same amount of new oil, plus 3 ounces. If no oil can be drained from old accumulator, add 2 ounces of new oil.
SIGNS OF EXCESSIVE OIL LEAKAGE
- As the DA-6 compressor has no oil sump, the compressor retains a minimum of refrigeration oil. Therefore, only the accumulator needs to be removed, drained, and its oil measured.
- If the amount recovered is less than 3 ounces, add 3 ounces of new oil to the system. If the amount is more than 3 ounces, add the same amount of new oil as that drained from the accumulator.
Note. If a new accumulator must be added to the DA-6 system, add an additional 3 ounces to compensate for that retained by the original accumulator desiccant.
HARRISON R-4, 4-CYLINDER COMPRESSOR OIL CHECKING
Note. Harrison Compressors, built by the Harrison Radiator Division of General Motors, may have been referred to in the past as Frigidaire, General Motors or Delco-Air Compressors.
Systems with this compressor are charged (new) with 6 ounces of refrigeration oil. Due to compressor's design (without oil sump), compressor does not have to be removed for oil measurement. Note the following situations for checking and adding oil with this compressor
- If compressor is replaced, remove, drain and measure oil. Replace with same amount of new oil plus one ounce. If evaporator is replaced, add 3 ounces of new oil. If condenser is replaced, add one ounce of new oil.
- If accumulator is to be replaced, remove, drain oil, and measure. Replace with same amount of new oil, plus 2 ounces to compensate for that retained by the original accumulator's desiccant.
SIGNS OF EXCESSIVE OIL LOSS
If system has lost excessive oil, remove the accumulator, drain and measure oil. DO NOT remove or drain compressor. If more than 3 ounces is found in accumulator, add same amount of new oil as was drained. If less than 3 ounces is measured, add 3 ounces of new oil. If a new accumulator is being installed, add 2 additional ounces of oil to replacement accumulator.
OIL CHARGE DOUBTFUL OR SYSTEM CONTAMINATED
If exact quantity of oil in system is in doubt or oil drained from components contains foreign particles, drain and flush system. Then, add a new charge of 6 ounces of refrigeration oil to system.
SANDEN (SANKYO) 5-CYLINDER COMPRESSOR
| CAUTION | When discharging air conditioning system, use only approved refrigerant recovery/recycling equipment. Make every attempt to avoid discharging refrigerant into the atmosphere. |
Scheme 1
- After compressor and system have been run, stop engine. Slowly discharge the system using approved refrigerant recovery/recycling equipment. Clean and cool the dipstick with R-12. (Scheme 1): Sanden (Sankyo) 5-Cylinder Compressor Oil Check
- Loosen the compressor mounting bolts, remove the drive belt, and move the compressor to a bench for easiest and most accurate measurement. Position the compressor so that the oil fill plug is at top dead center.
- Thoroughly clean the oil fill plug and the area around it. Loosen the fill plug slowly to allow trapped refrigerant pressure to escape through the loosened threads.
- The front plate hub has a lobe, which is indexed (notched) 180° from TDC of the cam rotor. Rotate the hub plate lobe until the index notch is 110° from bottom center. (Scheme 1) Check this position by looking through the oil fill hole and noting that the ball end of the top piston rod lines up with the fill hole.
- Looking at the front end of the compressor, insert the dipstick diagonally from upper left to lower left until the dipstick stop contacts the filler hole surface. Remove dipstick and note oil level. Oil level should be between the 4th and 6th increment on the dipstick (3-4 ounces). Add oil as necessary.
- If system components are being replaced, add refrigerant oil directly to them as indicated in the chart under "Typical Oil Replacement For Individual Components" in this chapter.