A/c System General Servicing: Other Ford Probe II

HANDLING/SAFETY PRECAUTIONS

1. Always work in a well-ventilated, clean area. Refrigerant (R-12 or R-134a) is colorless and invisible as a gas. Refrigerant is heavier than oxygen and will displace oxygen in a confined area. Avoid breathing refrigerant vapors. Exposure may irritate eyes, nose and throat.
2. The system's high pressure can cause severe injury to eyes and skin if a hose were to burst. Always wear eye protection when working around A/C system and refrigerant. If necessary, wear rubber gloves or other protective clothing.
3. Refrigerant evaporates quickly when exposed to atmosphere, freezing anything it contacts. If liquid refrigerant contacts eyes or skin (frostbite), DO NOT rub eyes or skin. Immediately flush affected area with cool water for 15 minutes and consult a doctor or hospital.
4. Never use R-134a in combination with compressed air for leak testing. Pressurized R-134a in the presence of oxygen (air concentrations greater than 60 percent by volume) may form a combustible mixture. DO NOT introduce compressed air into R-134a containers (full or empty), A/C system components, or service equipment.
5. DO NOT expose A/C system components to high temperatures (steam cleaning for example), as excessive heat will cause refrigerant system pressure to increase. Never expose refrigerant directly to open flame. If refrigerant needs to be warmed, place bottom of refrigerant tank in warm water. Water temperature MUST NOT exceed 125°F (52°C).
6. Use care when handling refrigerant containers. DO NOT drop, strike, puncture, or incinerate containers. Use Department Of Transportation (DOT) approved (DOT 4BW or DOT 4BA) refrigerant containers.
7. Never overfill refrigerant containers. The safe filling level of a refrigerant container MUST NOT exceed 60% of the container's gross weight rating. Store refrigerant containers at temperatures less than 125°F (52°C).
8. Freon (R-12) will be sold and stored in White colored containers, while R-134a refrigerant will be sold and stored in 30- or 50-pound Light Blue containers.
9. Refrigerant R-12 and R-134a must never be mixed, as they and their desiccants and lubricants are not compatible. If the refrigerants are mixed, system cross-contamination or A/C system component failure may occur. Always use separate servicing and refrigerant recovery/recycling equipment.
10. Read and follow equipment manufacturer's instructions for all service equipment to be used. The Material Safety Data Sheet (MSDS), provided by refrigerant manufacturer/supplier, contains valuable information regarding the safe handling of refrigerants.

IDENTIFYING R-134a SYSTEMS & COMPONENTS

To prevent refrigerant cross-contamination, use following methods to identify R-134a based systems and components.

Fittings & "O" Rings

All R-134a based A/C systems use 1/2" - 16 ACME threaded fittings (identifiable by square threads) and quick-connect service couplings. (Scheme 7)

Scheme 7

REFRIGERANT OILS

Refrigerant R-12 based systems use mineral oil, while R-134a systems use synthetic/Polyalkylene Glycol (PAG) oils. Using a mineral oil based lubricant with R-134a will result in A/C compressor failure due to lack of proper lubrication.

Note. Use only specified oil for the appropriate system and A/C compressor. Always check the underhood A/C specification label or A/C compressor label before adding refrigerant oil to A/C compressor/system. see scheme 2

The following R-134a refrigerant oils are currently available.

Ford

Use PAG (YN-12) Refrigerant Oil (Ford Specification WSH-M1C231-B or WSH-M17B19-A).

Note. Synthetic/PAG oils absorb moisture very rapidly, 2.3-5.6% by weight, as compared to a mineral oil absorption rate of .005% by weight.

SERVICE EQUIPMENT

Note. Ensure "O" rings are designed for use with specified refrigerant. Deterioration of "O" rings and system contamination will result if incorrect "O" rings are used.

Because R-134a is not interchangeable with R-12, separate sets of hoses, gauges and recovery/recycling equipment are required to service vehicles. This is necessary to avoid cross-contamination and damaging system.

All equipment used to service systems using R-134a must meet SAE standard. The service hoses on the manifold gauge set must have manual (turn wheel) or automatic back-flow valves at the service port connector ends. This will prevent refrigerant from being released into the atmosphere.

For identification purposes, R-134a service hoses must have a Black stripe along their length and be clearly labeled SAE J2196/134a. The low pressure test hose is Blue with a Black stripe. The high pressure test hose is Red with a Black stripe. The center test hose is Yellow with a Black stripe.

Note. Refrigerant R-12 service hoses will ONLY be labeled SAE J2196.

R-134a manifold gauge sets can be identified by one or all of the following

1. Labeled FOR USE WITH R-134a on set
2. Labeled HFC-134 or R-134a on gauge face
3. Light Blue color on gauge face

In addition, pressure/temperature scales on R-134a gauge sets are different from R-12 manifold gauge sets.

SIGHT GLASS INDICATOR

Note. Sight glass indicator conditions listed are for R-12 systems. Information for R-134a systems is not available from manufacturer.

Not all systems use a sight glass. If used, a sight glass may be mounted in receiver-drier (accumulator) or in discharge line. Refrigerant's condition can be visually checked while passing through sight glass. The following are possible conditions of sight glass indicator, which may help in the diagnosis of problems. (Scheme 8)

Note. Sight glass readings are not positive identification of a problem. Readings should be relied upon only when other system symptoms exist.

Clear Sight Glass

A clear sight glass indicates refrigerant level is correct or is excessively low for system circulation. Sight glass may be clear, but system may contain excessive refrigerant. This must be verified by test gauge readings.

Bubbly/Foamy Sight Glass

A bubbly or foamy sight glass indicates system is low on refrigerant, and air has probably entered system. If only occasional bubbles are noticed, during clutch cycling or system start-up, this may be a normal condition.

Oil Streaked Sight Glass

If oil streaks appear on sight glass, a lack of refrigerant may be indicated, and the system's compressor oil is circulating through the system.

Cloudy Sight Glass

A cloudy sight glass indicates desiccant contained in receiver-drier or accumulator has broken down and is being circulated through system.

Identifying Sight Glass Indicator Conditions. Scheme 8

STEM-TYPE VALVES

This manually operated service valve has adjustable stem located under a protective cap. Valve stem must be manually positioned when making gauge connections and/or reading system pressure on the gauges. (Scheme 9)

Identifying Stem-Type Service Valve Positions. Scheme 9

Back-Seated (Operating) Position

This is the normal operating position, which is also used for connecting and disconnecting manifold gauge set. Stem is turned fully outward to seal the service gauge port.

SCHRADER-TYPE VALVES

Note. Although similar in construction and operation to a tire valve, NEVER replace a Schrader-type valve with a tire valve.

Schrader valve is similar in construction and operation to a tire valve. When a test gauge hose is attached (hose has built-in valve core depressor), Schrader stem is pushed inward to the open position and allows system pressure to reach the gauge.

If test hose being used does not have a built-in core depressor, an adapter must be used. Never attach hoses or adapters to a Schrader valve unless it is first connected to manifold gauge set.

SPECIAL VALVE CONNECTORS

All vehicles with R-134a refrigerant use quick-disconnect service valves. To help prevent installing hoses and other parts used on R-12 systems, all fittings on R-134a systems use 1/2"-16 ACME threads.

Some Ford Motor Co. systems require installation of Adapter (D81L-19703-A) on discharge line for high-side gauge installation. For low-side gauge installation, it may be necessary to remove pressure switch from accumulator. Install Adapter (D87P-19703-A) between accumulator and pressure switch. Connect gauge to adapter.

MANIFOLD GAUGE SET

A manifold gauge set is used to determine system's high-side and low-side pressures, correct refrigerant charge, system diagnosis and operating efficiency. High (discharge) and low (suction) pressures must be compared to determine system operation. Manifold gauge sets for the 2 refrigerant types are basically the same except for fittings at ends of hoses. Fittings are different to ensure connection only to appropriate refrigerant system.

Low-Side Gauge

Low-side gauge, which may have a Blue identifying feature, is used to measure low-side (suction) pressure. Low-side gauge is also called a compound gauge because it can measure pressure and vacuum. Pressure scale ranges from 0 to 150 psi; vacuum scale ranges from 0 to 30 in. Hg.

High-Side Gauge

High-side gauge, which may have a Red identifying feature, is used to measure high-side (discharge) pressure. Gauge scale ranges from 0 to 500 psi.

1. Put on safety goggles, and cover vehicle's fender. Slowly remove protective caps from Schrader valves to check for leaky valves. CAUTION: Ensure hand valves on manifold gauge set are closed before connecting test hoses to Schrader valves.
2. Ensure service hoses are equipped with valve core depressor to match Schrader valve. Special adapters are required if service hoses do not have built-in core depressor. Ensure both manifold gauge hand valves are closed.
3. Connect low-side service hose to low-side (suction) service valve, and finger tighten connections. Connect high-side service hose to high-side (discharge) service valve, and finger tighten connections.

1. Put on safety goggles, and cover vehicle's fender. Place valves in back-seated position. Slowly remove protective caps from service valves to check for leaky valves. CAUTION: Ensure hand valves on manifold gauge set are closed before turning service valve to mid-position.
2. Attach low-side service hose to low-side (suction) service valve. Connect high-side service hose to high-side (discharge) service valve. Finger-tighten both connections.

Note. After test gauges are installed, test hoses must be purged of all air before proceeding with testing.

STABILIZING A/C SYSTEM

1. Once manifold gauge set is attached to system and test hoses have been purged (if required), system is ready for testing. Place all test hoses, gauge set and other equipment away from all moving parts of engine.
2. Start engine, and turn A/C controls to maximum cooling position. Set blower fan on high speed. Open doors and/or windows, and operate system for 5-10 minutes. System should now be stabilized and ready for test readings.

PRESSURE GAUGE INDICATIONS

Note. Pressure gauge indications are for R-12 systems only. For additional information see the A/C COMPRESSOR SERVICING or A/C COMPRESSOR REFRIGERANT OIL CHECKING articles in the AIR CONDITIONING & HEAT section.

The following typical pressure gauge indications represent conditions that may be encountered during R-12 system servicing. (Scheme 10)-14. Temperature and humidity, as well as other factors, affect pressure gauge readings. Compared to R-12 systems, pressure readings on R-134a systems are generally lower for low side pressure and higher for high side pressure. Pressure gauge indications should be used only as a guide.

Scheme 10

Scheme 11

Scheme 12

Scheme 13

Scheme 14

Scheme 15

Scheme 16

Scheme 17

Scheme 18

Scheme 19

REFRIGERANT RECOVERY/RECYCLING

Note. The use of recovery/recycling equipment is required by law.

Refrigerant recovery/recycling equipment is used to remove refrigerant from vehicle's A/C system without polluting atmosphere. To remove and recycle refrigerant, ALWAYS follow instructions provided with the refrigerant recovery/recycling equipment being used.

The removed refrigerant is filtered, dried and stored in a tank within the recovery/recycling equipment until it is ready to be pumped back into the vehicle's A/C system.

Note. Separate sets of hoses, gauges and refrigerant recovery/recycling equipment MUST be used for R-12 and R-134a systems. DO NOT mix R-12 and R-134a refrigerants, as their refrigerant oils and desiccants are NOT compatible.

1. Connect Rotunda Recovery/Recycling Equipment (078-00800) hoses to high-side and low-side service valves. See SERVICE VALVE LOCATIONS under SYSTEM SERVICE VALVES.
2. Turn refrigerant recovery/recycling equipment on. Allow unit to run until vacuum is obtained. Once vacuum reading is obtained, close inlet valve (if equipped) on refrigerant recovery/recycling equipment. Shut refrigerant recovery/recycling equipment off. NOTE: On some applications, refrigerant recovery/recycling system will automatically shut off through the use of a low pressure switch. On other applications, refrigerant recovery/recycling equipment must be manually shut off.
3. Allow system to remain closed for about 2 minutes while observing pressure readings on the refrigerant recovery/recycling equipment.
4. If pressure reading remains at zero, disconnect hoses from service ports. If pressure reading is greater than zero, repeat steps 2) and 3).

R-12

Manufacturer recommends flushing contaminated system with flushing agent using Rotunda Air Conditioning Reclaim System (158-0000 1).

R-134a

Information is not available from manufacturer.

EVACUATING A/C SYSTEM

1. Close both valves on manifold gauge set. Connect manifold gauge set to high-side and low-side service valves. See SERVICE VALVE LOCATIONS under SYSTEM SERVICE VALVES. Connect a hose to center connector on manifold gauge set and evacuation pump.
2. Open both valves on manifold gauge set. Operate evacuation pump until low-side vacuum reading is at least 29.5 in. Hg. Continue operating evacuation pump for 30 minutes.
3. Close both valves on manifold gauge set. Turn off evacuation pump. Observe low-side gauge. Any loss of vacuum in 5 minutes indicates a system leak. Perform leak testing procedure, and repair system as necessary. See LEAK TESTING.

CHARGING A/C SYSTEM

Note. Manufacturer does not recommend using one-pound cans. Using a charging station will allow precise measurement of refrigerant charge. See REFRIGERANT OIL & REFRIGERANT SPECIFICATIONS tables in the A/C COMPRESSOR SERVICING article for system capacities.

1. System must be evacuated before charging. With manifold gauge set connected (from evacuation procedures), attach refrigerant container to hose on center connector of manifold gauge set. Fully open refrigerant container valve, and purge air from center hose.
2. Disconnect electrical connector from clutch cycling pressure switch located on the accumulator. Install jumper wire between clutch cycling pressure switch connector terminals.
3. Open low-side valve on manifold gauge set, and allow refrigerant to enter system. When refrigerant is no longer being drawn into system, start and operate engine. Place A/C-heater controls on maximum cold position with blower fan on high speed. NOTE: In areas where ambient air temperature is high, it may be necessary to operate a high output fan to blow air through condenser and radiator.
4. When proper amount of refrigerant has been added, close low-side valve on manifold gauge set. Remove jumper wire, and connect clutch cycling pressure switch. Reinstall electrical connector.
5. Operate system to verify proper operation and normal system pressures. Disconnect manifold gauge set. Install service port caps. Check system for leaks.