A/c System General Servicing Ford Bronco II I

DISCHARGING A/C SYSTEM

SERVICE VALVE LOCATIONS

COMPRESSOR OIL CHECKING - GENERAL PROCEDURES

Some models have compressor-mounted service valves that allow oil checking by isolating the compressor. On all others, system must be discharged using approved refrigerant recovery/recycling equipment 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 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

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 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.

Ford & Nippondenso 6-Cylinder Compressor Oil Check. Scheme 36

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

During Compressor Replacement

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.

During Component Replacement

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.

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

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.

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.

ORIFICE TUBE REPLACEMENT

Note. Some models have a non-removable orifice tube. On these models, the complete liquid line assembly must be replaced.

Scheme 37

Scheme 38

Scheme 39

1. Locate orifice tube. On Ford Crown Victoria, Mercury Grand Marquis, Lincoln Town Car and all Light Truck models (except Vans), the orifice tube is located in the evaporator inlet pipe. Vans use an expansion valve instead of an orifice tube. On all other models, tube is part of the liquid line near the condenser.
2. Discharge refrigerant from system using approved refrigerant recovery/recycling equipment. Disconnect liquid line from evaporator core. Cap the line. Pour small amount of refrigeration oil into evaporator core inlet tube to lubricate orifice tube and its "O" rings. Engage orifice tube remover tool (D80L 19990 A or Motorcraft No. YT 1008 or equivalent) with the 2 tangs on fixed orifice tube. (Scheme 37) (Scheme 37): Removing Orifice Tube (Scheme 38): Removing Broken Orifice Tube CAUTION: Do not attempt to twist or rotate tube in core pipe, as it may break inside pipe.
3. Hold "T" handle of orifice tube remover tool to keep it from turning and run the nut down against evaporator core line until orifice tube is pulled from line. If orifice tube breaks in evaporator core line, it must be removed with extractor tool (D80L 19990 BB or Motorcraft YT 1009 or equivalent).
4. To remove broken orifice tube, insert screw end of extractor tool into evaporator core line and thread screw end of tool into brass tube in center of broken orifice tube. Run the tool nut down against liquid line, removing orifice tube. (Scheme 38)
5. If only the brass center tube is extracted, insert screw end of tool into evaporator core line. Screw end of tool into fixed orifice tube body. Remove tube body from evaporator core line.
6. To install, lubricate the 2 "O" rings on the orifice tube with clean refrigeration oil. Place the orifice tube in the removal tool. Insert the orifice tube into the evaporator tube until orifice tube seats at the stop. (Scheme 39) (Scheme 39): Installing Orifice Tube
7. Remove the extractor tool and reverse the rest of removal procedure to complete installation. Use a new "O" ring when installing liquid line to evaporator core line. Leak-test, evacuate and recharge system. Check system for proper operation.

BEFORE OPENING THE SYSTEM

Before disconnecting any lines or fittings, the system must be completely discharged using approved refrigerant recovery/recycling equipment.

DISCONNECTING LINES & FITTINGS

1. After system is discharged, carefully clean entire area around coupling nut to prevent dirt from entering system. Always use 2 wrenches to avoid twisting or distorting lines and fittings (hold fitting with one wrench while loosening coupling nut with the other).
2. Ford spring-coupling fittings require a special coupling tool (Motorcraft YT 1056) to open or close. See procedure under Connecting Lines and Fittings.
3. Cap or plug all LINES and FITTINGS immediately to prevent entry of air and moisture into system. Do not remove these caps until connections are being made.

COMPONENT REPLACEMENT

When components are replaced, system oil level must be adjusted. Add refrigerant oil to replacement component. See Compressor Oil Check article, as well as, Component Oil Replacement Quantities table under A/C SYSTEM SPECS article in this section.

CONNECTING LINES & FITTINGS

1. A new "O" ring should be used in all instances when connecting lines and fittings (dip "O" ring in clean refrigerant oil and make certain it is not twisted during installation). Always use 2 wrenches to avoid twisting or distorting lines and fittings. Tighten coupling nuts securely.
2. Ford spring-coupling fittings require a special coupling tool (Motorcraft YT 1056) to open or close. Use the following procedure to connect or disconnect the spring-coupling fitting.

Scheme 40

1. Discharge system using approved refrigerant recovery/recycling equipment. Place proper end of tool over the refrigerant line. Tool fits both 3/8" and 1/2" fittings. Push tool into fitting cage to release spring inside. Pull lines apart and remove tool.
2. Before connecting, check internal spring for damage. If necessary, pry spring out and replace it. Clean fittings and install new "O" rings. (Scheme 40): Assembly Ford Spring-Coupling Fitting CAUTION: Use ONLY "O" rings designed for these Ford fittings (Motor- craft YF 982). Normal refrigerant "O" rings will not seal.
3. Lubricate both sides of fitting with clean refrigerant oil. Assemble the fitting by pushing together with a slight twisting motion. Check to ensure spring is over flared end of female fitting.

PLACING SYSTEM IN OPERATION

After component replacement and/or system servicing has been completed and all connections have been made, proceed as follows

1)Evacuate the system using vacuum pump.

2)Charge the system with R-12. See Refrigerant Capacity table under A/C SYSTEM SPECS article in this section.

3) Leak-test the system, with particular attention to all new connections and components.

4) Make a performance test of the system. Never assume that a recharging has automatically corrected a problem.

BASIC DIAGNOSTIC PROCEDURES

Diagnosis is an important first step in A/C system servicing. To save time and effort, systems should be carefully checked to identify the causes of poor performance. By using the following diagnostic charts, defective components or system damage can be quickly located. To identify problems that are specific to one system, refer to the repair article in this section.

PREPARATION FOR TESTING

1. Attach Low and High side gauges.
2. Start engine and allow it to warm up.
3. Set system to COOL and blower to HIGH.
4. Open car doors and hood.
5. Run at fast idle for 2-3 minutes.

1. Attach Low and High side gauges.
2. Start engine and allow it to warm up.
3. Set system to COOL and blower to HIGH.
4. Open car doors and hood.
5. Run at fast idle for 2-3 minutes.

ALTITUDE PRESSURE VARIATIONS

ALTITUDE PRESSURE VARIATIONS

ALTITUDE VACUUM VARIATIONS

OPERATIONAL TEST GAUGE READINGS

NORMAL SYSTEM OPERATING PRESSURES (PSI) (1)

Air Conditioning System Performance Check. Scheme 41

Ambient Temperature/Pressure Chart. Scheme 42

Evaporator Temperature/Pressure Chart. Scheme 43

A/C SYSTEM DIAGNOSIS WITH GAUGES

AIR CONDITIONING DIAGNOSIS WITH GAUGES FOR SYSTEMS WITH INSUFFICIENT OR NO COOLING

FLUSHING A/C SYSTEM

Note. Accumulator must be replaced when system is flushed. The Ford Fixed Orifice Tube (FFOT) must be replaced or cleaned with flushing refrigerant or mineral spirits when system is flushed. See ORIFICE TUBE REPLACEMENT in this article.

All Models

1. Discharge system using approved refrigerant recovery/recycling equipment. Remove A/C compressor and accumulator. See appropriate article in A/C-HEATER section in this manual for compressor and accumulator removal. The A/C compressor must be removed for cleaning. NOTE: DO NOT connect suction line to compressor. This line will be connected once system is flushed.
2. Remove and replace or clean orifice tube. See ORIFICE TUBE REPLACEMENT in this article.
3. Complete system flushing before installing liquid line. Disconnect discharge hose at condenser inlet and clamp a length of 1/2" hose to condenser pipe. Place open end of hose in a container to catch flushed refrigerant.
4. Connect a can of R-12 to charging valve on top of charging cylinder. Using R-11 or R-113 and flushing equipment, back-flush condenser and liquid line from compressor discharge line through condenser.
5. After flushing, lay charging cylinder on side to prevent more flushing agent from entering system. Open valve and flush flushing agent out using R-12. Stand flushing cylinder upright and flush compressor discharge hose. Remove 1/2" hose.
6. Install new lubricated "O" rings and all lines. To connect spring lock couplings, fit female fitting over male fitting and push fittings together until garter spring snaps over flared end of female fitting. Check compressor for proper amount of refrigeration oil. Install compressor. Evacuate system and recharge with R-12. Leak test A/C system.

1. Remove service valve caps and install gauges. See SERVICE VALVE LOCATIONS table. Connect center hose to evacuation pump. Open both high and low gauge valves and start evacuation pump.
2. Operate evacuation pump until at least 25" of vacuum is reached on low side gauge. If vacuum reading cannot be reached, system has a leak. Add one pound of R-12. Leak test and repair. Perform evacuation procedure.
3. Continue operating evacuation pump for 15 minutes. If compressor, evaporator, refrigerant line, etc. have been replaced, operate evacuation pump for at least 30 minutes.
4. Close gauge high and low valves. Turn off evacuation pump and observe low side gauge. If vacuum reading drops in 5 minutes, system has leak. Perform leak testing procedure and repair.

CHARGING A/C SYSTEM

Note. Manufacturer does not recommend using one pound cans. Using a charging station will allow precise measurement of R-12 charge.

1. System must be evacuated before charging. With gauge set attached from evacuation procedures, attach R-12 container to center gauge hose. Fully open R-12 container valve and purge air from center hose.
2. Disconnect electrical connector at clutch cycling pressure switch and jumper connector. Open low side gauge valve and let R-12 enter system. When no more R-12 is being drawn into system, start and run engine. Place A/C-heater controls to "MAX" cold with blower speed on high. NOTE: In high temperature areas, it may be necessary to operate a high volume fan to blow air through condenser and radiator.
3. When proper amount of R-12 has been added, close gauge service valve. Remove jumper wire and connect clutch cycling pressure switch.
4. Operate system to verify proper operation and normal system pressures. Disconnect gauge set and install service port caps. Check system for leaks.

LEAK TESTING

Operate system to stabilize high and low side pressures. Turn engine off. Using an R-12 leak detector, check all refrigerant line connections for leaks. Check compressor seal area and condenser.

R-12 is heavier than air. Always check for leaks at bottom of refrigerant lines and components. Refrigerant oil will leak with R-12. Visually check all connections and compressor clutch area for oil stains. If compressor shaft seal is leaking, a fresh oil streak will normally be seen on underside of hood above compressor clutch.

Always perform leak testing after A/C service. Move R-12 leak detector slowly to check for leaks, as leaks will not be detected if leak testing is performed too quickly.