A/c Compressor Oil Checking GMC Cab & Chassis R3500

REFRIGERANT OIL

Only new, pure, moisture-free refrigerant oil should be used in the air conditioning system. This oil is highly refined and dehydrated to a point where moisture content is less than 10 parts per million. The oil container must be tightly closed at all times when not in use, or moisture will be absorbed from the air and introduced into the refrigeration system.

DISCHARGING SYSTEM

If compressor has stem-type service valves, it can be isolated and removed without discharging entire system. Otherwise, discharge system completely using approved refrigerant recovery/recycling equipment before loosening any fittings.

DISCONNECTING LINES & FITTINGS

After system is discharged, carefully clean area around all fittings to be opened. Always use 2 wrenches when tightening or loosening fittings to avoid twisting or distorting lines. Cap or plug all openings as soon as lines are removed. Do not remove caps until immediately before connections are made. This will keep entry of air and moisture to a minimum, reducing the chance of damage to components.

PLACING SYSTEM IN OPERATION

After component service or replacement has been completed and all connections have been made, evacuate system thoroughly with a vacuum pump. Charge system with proper amount of refrigerant and perform a leak test. Be sure to check all fittings that have been opened. After system has been leak tested, make a system performance check.

HARRISON A-6, 6-CYLINDER

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

1. 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 and install compressor filled with 10 ounces total.
2. 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

1. 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.
2. If amount drained is more than 8 ounces, flush system. Replace accumulator and 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 HR-6, 6-CYLINDER

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.

Note. The Harrison DA-6 was replaced in 1988 by the HR-6. Although there were some internal changes, the compressors remain essentially the same.

Systems with this compressor are fully charged with 8 ounces of refrigeration oil. Due to the compressor's design (without oil sump), the compressor 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

1. 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.
2. 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

1. As the 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.
2. 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 system, add an additional 3 ounces to compensate for that retained by the original accumulator desiccant.

HARRISON R-6, 4-CYLINDER

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

1. 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.
2. 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.

Note. Also see Component Oil Replacement Quantities chart under "SERVICE SPECIFICATIONS" in this section.

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.

HARRISON V5, 5-CYLINDER

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.

1. When a 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
2. 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.
3. 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 system, add an additional 2 ounces of oil to the compressor to compensate for that retained by the original accumulator desiccant.

10P15, 10P15C & 10PA20

To ensure that the Nippondenso 10-cylinder compressor has the proper amount of lubricating oil, discharge the system using approved refrigerant recovery/recycling equipment and remove the compressor. Remove the service valve assembly. Turn the compressor upside down and drain the oil from it. Once the oil has been drained, refill the compressor with 2.0-3.4 oz. of Densooil 6, Suniso No. 5GS or equivalent compressor oil.