A/c Compressor Oil Checking Ford Cab & Chassis Ranger

COMPRESSOR OIL CHECK - GENERAL PROCEDURES

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

1. Connect manifold gauge set to service valves on compressor. Close both gauge valves. Open both service valves to the mid-position.
2. 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).
3. Front-seat the discharge valve. Loosen oil check plug

PURGING COMPRESSOR

1. Remove gauge set and place caps on service valve ports. Back-seat the suction service valve to allow refrigerant to enter compressor.
2. Loosen discharge port valve slightly. Loosen valve port

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.

FORD WITH HR 980 4-CYLINDER COMPRESSOR

The Tecumseh 4-cylinder compressor system requires a refrigeration oil charge of 8 ounces. If a component is removed from the system, some oil is lost with that component. The procedures for replacing oil are as follows

During Compressor Replacement

A new compressor comes charged with 8 ounces of refrigeration oil. Before installing the compressor, drain out 4 ounces from the new compressor. This will maintain the system total charge within the 8 ounce limit.

During Component Replacement

When replacing the evaporator, add 3 ounces; for the condenser, add one ounce. If an accumulator is replaced, drain oil from accumulator through the pressure sensing switch fitting (Schrader valve removed). Measure the amount of oil removed, and add that amount plus one ounce to the new accumulator. No oil needs to be added to compensate for loss when valves or hoses are replaced.

Scheme 1

1. Check compressor oil level only if any portion of refrigerant system is being replaced, or if system was discharged due to a leak. On horizontally mounted compressors, oil check hole is located on side of crankshaft which faces up. (Scheme 1): Checking Compressor Oil Level Horizontally Mounted Unit
2. On opposite or downward side there is a corresponding boss provided on inner wall as an alternate oil check hole, for different mounting. When checking oil level on such a compressor, angle the dipstick such that it bottoms against lower side of compressor and not against boss.
3. After system has been charged, operate for approximately 10 minutes, or until pressures have stabilized (with ambient temperature of 60°F or higher). Stop engine and discharge entire system using approved refrigerant recovery/recycling equipment. Fabricate a dipstick according to specifications. (Scheme 1)
4. Remove oil filler plug and insert dipstick until it bottoms. If necessary, slightly rotate compressor crankshaft by hand so that dipstick will clear. Level on dipstick must be within specifications.

TECUMSEH COMPRESSOR OIL LEVEL

MODELS WITH STEM TYPE SERVICE VALVES

Oil level should be checked whenever the system is discharged for service part replacement, or if system has self-discharged due to component malfunction. Oil level is checked with compressor in operating position.

It is important when checking oil level that system has been operated and car interior temperature has cooled to desired setting. This is necessary to stabilize amount of oil in the system.

Note. The following oil checking procedure details isolating the compressor prior to checking. It is possible to discharge the entire system and then check the oil level.

1. Turn both the high and low pressure service valve clockwise as far as possible (front-seat position). Loosen cap on the high pressure service valve and bleed residual pressure from compressor. CAUTION: Only loosen cap a small amount and DO NOT remove cap until pressure is totally relieved. NOTE: Oil level check plugs are located on either side of compressor crankcase; use check plug which is most convenient.
2. Fabricate a suitable dipstick according to specifications. Check oil level. Add clean refrigerant oil if necessary. Install new "O" ring seal on filler plug.
3. When oil check is complete, compressor must be purged of air before operating the system. Refer to procedure under Component Replacement.

Dimensions for Tecumseh Compressor Oil Level Dipstick. Scheme 2

Ford & Nippondenso 6-Cylinder Compressor Oil Checking. Scheme 3

FORD WITH FS-6 & NIPPONDENSO 6P148 6-CYLINDER COMPRESSORS

When inspecting the system to determine oil loss, check for signs of leaking (a wet, shiny looking spot on system components). If a component is removed after the system has been operated, some oil will remain in the component. If oil leak is noted or components replacement is required, oil will have to be restored to original level, as follows

Discharge system using approved refrigerant recovery/recycling equipment and replace components as necessary. A new FS-6 or 6P148 compressor contains 10 ounces of new refrigeration oil. Prior to installing new compressor, drain 4 ounces of the oil from new compressor. This will maintain total system charge of 10 ounces.

When replacing components other than the compressor, oil must be added to new component to maintain system charge at 10 ounces. If evaporator is replaced, add 3 ounces; if the condenser is replaced, add one ounce.

If accumulator is to be replaced, remove accumulator. Drain oil from old accumulator and measure amount removed. Before installing new accumulator, add the same amount of oil plus one ounce.

Compressor Failure & System Contaminated

If either of these situations exists, discharge system using approved refrigerant recovery/recycling equipment and remove compressor, accumulator and orifice tube. Inspect orifice tube for contaminants. Clean and replace as necessary. Flush entire system. Install a new compressor (if necessary) and a new accumulator. New compressors are charged with proper amount of oil, 10 ounces. If reinstalling old compressor, add 10 ounces of new refrigeration oil through suction port. Evacuate and charge system.