HVAC System - General Servicing: Other Chevrolet Prizm I

HANDLING/SAFETY PRECAUTIONS

1. Always work in a well-ventilated, clean area. Refrigerant 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. Always wear eye protection when working around A/C system and refrigerant. The system's high pressure can cause severe injury to eyes and skin if a hose were to burst. 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). CAUTION: When R-134a is exposed to an open flame, drawn into engine, or detected with a Halide (propane) leak tester, a poisonous gas is formed. Keep work areas well ventilated.
6. Use care when handling refrigerant containers. DO NOT drop, strike, puncture, or incinerate containers. Use DOT 4BW or DOT 4BA approved 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. R-134a refrigerant is sold and stored in 30- or 50-pound Light Blue containers, while Freon (R-12) is stored in White colored 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 ports. (Scheme 9)

Scheme 9

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.

Following are the most common R-134a refrigerant oils used by most domestic vehicles

Chrysler Corp., Eagle & Jeep

Use ND-8 PAG oil, SUN PAG 56 oil, SP-10 PAG Oil, or SP-20 PAG oil.

Ford Motor Co.

Use YN-12B or YN-12C PAG Refrigerant Oil (specification WSH-M1C231-B) or SP-20 PAG Oil (specification WST-M1C231-B2).

General Motors

On all models except Saturn, use PAG Refrigerant Oil (Part No. 12345923). On Saturn, use Saturn PAG refrigerant oil.

Note. PAG oil absorbs moisture very rapidly, 2.3-5.6 percent by weight as compared to a mineral oil absorption rate of .005 percent by weight.

Note. Use ONLY the specified oil for the appropriate system or A/C compressor. Always check the underhood A/C specification label or A/C compressor label before adding refrigerant oil to A/C system.

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. (Scheme 10) 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.

Schrader Service Valve (Compressor Location Shown). Scheme 10

SPECIAL VALVE CONNECTORS

On some General Motors models, thread size on high-side service valve (3/8" - 24 threads) is different from thread size on low-side service valve (7/16" - 20 threads). Special adapters are required to make this connection. (Scheme 11) These adapters are available in 45-degree and 90-degree angles in addition to straight-fixed and flexible adapters.

Flexible High Side Adapter. Scheme 11

R-134a SERVICE VALVES/PORTS

All vehicles with R-134a refrigerant use quick-disconnect service valves/ports. All R-134a systems use quick-disconnect fittings with sealing caps that thread into inside of service port instead of onto outside of service port.

The high side uses a large service port, and the low side uses a small service port. (Scheme 9) The R-134a service ports have internal metric threads to help prevent the accidental connection of R-12 servicing equipment.

There are 2 types of quick-disconnect service couplings which can be used on R-134a systems. One type of service coupling depresses service port valve when connection is made. The other type connects onto service port but will not depress service port valve until a knob is rotated. (Scheme 12)

Scheme 12

SERVICE EQUIPMENT

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 J2210. 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-side test hose is Red with a Black stripe. The center test hose is Yellow, or White, with a Black stripe.

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

All 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.

MANIFOLD GAUGE SET

A manifold gauge set is used to determine the system's high-side and low-side pressures, correct refrigerant charge, 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.

1. 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.
2. 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.

CONNECTING GAUGE SET

Note. R-134a quick disconnect service couplings are connected in the same sequence as Schrader-type service valves.

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 and the hose-end shutoff valves are closed before attaching test hoses to Schrader valves.
2. Ensure service hoses are equipped with valve core depressor to match Schrader valve. If not, install special adapters for this purpose. If the high-side service hose connector will not fit on high-side Schrader valve, a special adapter must be used. See «SPECIAL VALVE CONNECTORS»(ref-118-S07016742912000030700000) .
3. Ensure both manifold gauge set hand valves are closed. 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.

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, the 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 (full cold or MAX A/C). Set blower on high speed. Open doors and/or windows. Operate system for 5-10 minutes. System should now be stabilized and ready for test readings.

PRESSURE-TEMPERATURE RELATIONSHIP

A refrigerant, when confined in an enclosed space, increases in pressure as the temperature increases. Conversely, if the temperature is lowered, the pressure also decreases.

Depending on temperature, a corresponding pressure will exist in such an enclosed space. For example, at 70°F (21.1°C) a gauge will indicate about 71.0 psi (5.0 kg/cm 2 ). The R-134a PRESSURE- TEMPERATURE RELATIONSHIP table shows this relationship.

R-134a PRESSURE-TEMPERATURE RELATIONSHIP

PRESSURE GAUGE READINGS

The pressure gauge readings shown represent an expansion valve type system using a Nippondenso 10-cylinder compressor. (Scheme 13)through (Scheme 21). Gauge indications will vary depending on system configuration and compressor application.

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 readings should be used only as a guide.

Note. For additional information, see the latest MITCHELL® AUTOMOTIVE AIR CONDITIONING BASIC SERVICE TRAINING MANUAL.

Normally Functioning R-134a A/C System. Scheme 13

Some Moisture In R-134a System. Scheme 14

Low R-134a Charge. Scheme 15

Poor R-134a Refrigerant Circulation. Scheme 16

No R-134a Refrigerant Circulation. Scheme 17

Insufficient Cooling Of Condenser Or R-134a Refrigerant Overcharge. Scheme 18

Air In R-134a System. Scheme 19

Expansion Valve Improperly Mounted Or Heat Sensing Tube Defective (Opening Too Wide). Scheme 20

Compressor Malfunction. Scheme 21

Note. Replace orifice tube whenever compressor is replaced. Fixed orifice tube is located in the condenser-to-evaporator liquid line.

Note. DO NOT use pliers to remove fixed orifice tube or twist orifice tube in liquid line. Doing so will cause plastic orifice tube body to break inside condenser-to-evaporator liquid line.

REFRIGERANT RECOVERY/RECYCLING

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, manifold gauge set 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.

CHRYSLER CORP.

Manufacturer recommends using refrigerant recovery/recycling equipment which meets SAE standard J1991 or J2210. Always follow instructions provided with the recovery/recycling equipment being used.

1. Connect hoses from Recovery/Recycling/Charging Center (023-00150) to high-side and low-side service valves. See «SERVICE VALVE LOCATIONS»(ref-118-S16764253362000030700000) under SYSTEM SERVICE VALVES.
2. Turn equipment on and recover refrigerant according to equipment manufacturer's operating instructions. Allow equipment to operate until refrigerant is recovered. Close inlet valve (if equipped) on refrigerant recovery/recycling/charging center and turn equipment off. NOTE: On some applications, refrigerant recovery/recycling/charging center will automatically shut off through the use of a low pressure switch. On other applications, refrigerant recovery/recycling/charging center must be manually shut off.
3. Allow A/C system to remain closed for about 2 minutes while observing vacuum pressure readings. If vacuum pressure reading increases, repeat step 2 until vacuum pressure readings remain stable for 2 minutes. If vacuum pressure readings remain stable for 2 minutes, disconnect hoses from service ports and perform required A/C system repairs.

Manufacturer recommends using A/C Refrigerant Recovery, Recycling And Recharging (ACR4) System (J-39500). The ACR4 system has one filtering cycle during recovery plus an automatic multiple pass filtering during evacuation cycle. Follow manufacturer's instructions provided with ACR4 equipment being used.

JEEP

Manufacturer recommends using refrigerant recovery/recycling equipment which meets SAE standard J1991 or J2210. Always follow instructions provided with the recovery/recycling equipment being used.

Information is not available from manufacturer.

Note. DO NOT flush accumulator/receiver-drier, muffler, hoses and thermal expansion valve/fixed orifice tube as residual flushing agent cannot be completely removed from these components. These components are generally replaced after A/C system contamination. Hoses can be reused, unless they are clogged with debris. Only flush evaporator core and condenser core, and metal inlet and outlet lines.

1. Manufacturer recommends flushing contaminated system using one gallon of Ford A/C System Flushing Solvent (F4AZ-19579-A), a Filter (FL-1A), an A/C Flusher Fitting Kit (014-00992). DO NOT reuse flushing solvent and filter, they are intended to be used on one vehicle only.
2. Discharge A/C system, using approved refrigerant recovery/recycling equipment. Flush specified A/C components using A/C System Flusher (014-00991), according to manufacturer's operating instructions.
3. If an A/C system flusher is not available to clean A/C system, an in-line filter kit can be used. Filter kit is installed before replacement compressor, accumulator/receiver-drier, muffler, and thermal expansion valve/fixed orifice tube have been installed.
4. Filter kits are used with either a rubber lined suction hose or with a nylon lined suction hose located between compressor and evaporator. Rubber lined hose has a wall thickness of 1/4" and nylon lined hose has a wall thickness of 1/8". (Scheme 22)
5. The filter kit for either type hose has 2 filters. A temporary pancake filter and a permanent in-line suction filter. Pancake filter is temporarily installed between condenser and condenser-to-evaporator line. (Scheme 23) Permanent filter is installed in suction line between accumulator and compressor.
6. Install replacement components (compressor, accumulator and fixed orifice) with correct amount of refrigerant oil. See COMPRESSOR REFRIGERANT OIL CHECKING article.
7. Cut suction hose between compressor and accumulator (closer to compressor). Remove a length of suction hose to accommodate suction filter. Measure side wall of suction hose and install appropriate filter with "O" rings and filter clamps. If side wall is 1/4", use in-line filter labeled USE WITH RUBBER INNER LINED HOSE. If side wall is 1/8", use in-line filter labeled USE WITH NYLON INNER LINED HOSE. Ensure arrow on filter is pointing in direction of refrigerant flow. Tighten hose clamps to 54 INCH lbs. (6 N.m). (Scheme 22)
8. Install pancake filter in liquid line between condenser and condenser-to-evaporator line. Ensure filter inlet (label) is toward condenser. Evacuate, charge, and leak test A/C system. See «EVACUATING A/C SYSTEM»(ref-118-S28497345752000030700000), «CHARGING A/C SYSTEM»(ref-118-S21177302952000030700000) and «LEAK TESTING»(ref-118-S08729038682000030700000). Check filters and hoses for clearance from other engine components. Use tie straps if necessary.
9. Place an external cooling fan in front of radiator. Select MAX A/C operation and set blower motor speed to maximum. Start engine and allow to idle. Ensure A/C is operating properly. Slowly increase engine speed to 800 RPM, then 1000 RPM, and then to 1200 RPM. With engine speed set to 1200 RPM, operate engine for one hour with A/C system operating.
10. Stop engine. Discharge A/C system, using approved refrigerant recovery/recycling equipment. Remove pancake filter, hoses and fittings. Discard pancake filter. Reconnect liquid line, evacuate, charge, and leak test A/C system. Ensure A/C system is operating properly.

Scheme 22

Scheme 23

Information is not available from manufacturer.

Information is not available from manufacturer.

EVACUATING A/C SYSTEM

Avenger 2.0L & Sebring 2.0L

1. Ensure all manifold gauge set valves are closed. Connect manifold gauge set service valves. Connect vacuum pump adapter to vacuum pump. Connect manifold gauge set Yellow hose to vacuum pump adapter.
2. Fully open manifold gauge set low-pressure valve and adapter valve, and start vacuum pump. Operate vacuum pump for about 10 minutes until low-side vacuum reading is 29.5 in. Hg or more. Turn vacuum pump off and observe vacuum gauge.
3. If A/C system maintains specified vacuum for 5 minutes, system is okay. If A/C system cannot get to or maintain specified vacuum for 5 minutes, ensure connections are tight and repeat evacuation. If A/C system still does not maintain specified vacuum, check for defective vacuum pump or leak in A/C system or gauge set. See «LEAK TESTING»(ref-118-S08729038682000030700000) . Repair or replace components as necessary.

Avenger 2.5L & Sebring Coupe 2.5L

Connect approved recovery/recycling equipment to vehicle. Evacuate A/C system using recovery/recycling equipment according to manufacturer's instructions.

Dakota, Durango, Ram Pickup & Ram Van/Wagon

1. Connect approved recovery/recycling equipment and manifold gauge set. Fully open manifold gauge set low-side and high-side valves, and start vacuum pump. Operate vacuum pump until low-side vacuum reading of 26 in. Hg or more. Close all valves and turn vacuum pump off. Observe vacuum gauge and go to next step.
2. If A/C system maintains specified vacuum for 5 minutes, restart vacuum pump, open low-side and high-side valves, and evacuate system for an additional 10 minutes. Close all valves. Turn vacuum pump off and disconnect pump.
3. If A/C system cannot get to or maintain specified vacuum, check for a defective vacuum pump or a leak in A/C system or gauge set. See «LEAK TESTING»(ref-118-S08729038682000030700000) . Repair or replace components as necessary.

All Other Models

1. Connect approved recovery/recycling equipment and manifold gauge set to vacuum pump. Fully open manifold gauge set suction and discharge valves, and start vacuum pump. Operate vacuum pump at least 45 minutes with a low-side vacuum reading of 26 in. Hg or more (28 in. Hg or more on Neon). Close all valves. Turn vacuum pump off and observe vacuum gauge.
2. If A/C system maintains specified vacuum for 30 minutes, open all valves, start vacuum pump and operate for an additional 10 minutes. Close all valves. Turn vacuum pump off and disconnect pump. If A/C system cannot get to or maintain specified vacuum for 30 minutes, check for a defective vacuum pump or leak in A/C system or gauge set. See «LEAK TESTING»(ref-118-S08729038682000030700000) . Repair or replace A/C system components as necessary.

1. If using approved Recovery/Recycling/Charging Center (023-00150) connect to high-side and low-side service valves. See «SERVICE VALVE LOCATIONS»(ref-118-S16764253362000030700000) under SYSTEM SERVICE VALVES. Connect manifold gauge set center hose to vacuum pump.
2. Open both valves on manifold gauge set. Operate vacuum pump until low-side vacuum reading is at least 29.5 in. Hg (as close to 30 in. Hg as possible). Operate vacuum pump for at least 45 minutes.
3. Close both valves on manifold gauge set. Turn off vacuum pump. Observe low-side gauge. Any loss of vacuum in 5 minutes indicates a system leak. Perform leak testing procedure. See «LEAK TESTING»(ref-118-S08729038682000030700000) . Repair system as necessary and repeat evacuation procedure.

Manufacturer recommends using A/C Refrigerant Recovery, Recycling And Recharging (ACR4) System (J-39500). The ACR4 system has one filtering cycle during recovery plus an automatic multiple pass filtering during evacuation cycle. Follow manufacturer's instructions provided with ACR4 equipment being used.

1. Connect approved recovery/recycling equipment and manifold gauge set. Fully open manifold gauge set low-side and high-side valves, and start vacuum pump. Operate vacuum pump until low-side vacuum reading of 26 in. Hg or more. Close all valves and turn vacuum pump off. Observe vacuum gauge, go to next step.
2. If A/C system maintains specified vacuum for 5 minutes, open low-side and high-side valves, restart vacuum pump and operate for an additional 10 minutes. Close all valves. Turn vacuum pump off and disconnect pump.
3. If A/C system cannot get to or maintain specified vacuum, check for a defective vacuum pump or leak in A/C system or gauge set. See «LEAK TESTING»(ref-118-S08729038682000030700000) . Repair or replace components as necessary.

CHARGING A/C SYSTEM

Avenger 2.0L & Sebring Coupe 2.0L

1. Ensure A/C system has no leaks and has been evacuated. See «EVACUATING A/C SYSTEM»(ref-118-S28497345752000030700000) and «LEAK TESTING»(ref-118-S08729038682000030700000) . Locate sight glass on receiver-drier and ensure it is clean. Close low-pressure adapter valve and remove from manifold gauge set.
2. Connect low-pressure adapter valve to refrigerant container and open container valve. Ensure Blue charging hose is properly connected to vehicle low-pressure service valve. Open adapter valve.
3. If refrigerant is not drawn in, fully close adapter valve and check for hose connection leaks. If leak is detected, retighten connections and repeat A/C system evacuation. See «EVACUATING A/C SYSTEM»(ref-118-S28497345752000030700000) .
4. If refrigerant is drawn in, start engine. Turn A/C on and set temperature control to maximum cold and blower motor to low speed. Operate engine at 1500 RPM. As refrigerant is drawn into system, foam or bubbles will appear in sight glass.
5. System charge will be close to full when sight glass is clear, compressor clutch is engaged, and compressor suction and discharge line temperatures are similar. System charge will be complete when sight glass is clear, compressor clutch is engaged, compressor discharge line is warm and suction line is cool.
6. When proper amount of refrigerant has been added, stop engine. Close refrigerant container and adapter valve, and disconnect gauge set.

Breeze, Cirrus, Concorde, Intrepid, LHS, Stratus & 300M (Manifold Gauge Set Method)

1. Attach clamp-on Thermocouple (80PK-1A) to liquid line, as close to condenser outlet as possible. Attach manifold gauge set to vehicle.
2. Set parking brake, and place transaxle in Park position. Start engine and allow to idle. Set A/C controls to outside air, panel mode, full cool, and high blower speed. Turn A/C on, and open windows. Operate system for a few minutes to allow system to stabilize.
3. Place cardboard over front grille area, to block airflow through part of condenser, to set A/C pressure to 260 psi (18.3 kg/cm 2 ). This will stop cooling fans from alternating speeds and maintain constant pressure.
4. Record temperature reading at liquid line and discharge pressure reading on gauges. Compare readings with values in «REFRIGERANT CHARGE LEVEL»(ref-118-S04166765522000030700000) table.
5. Depending on system charge condition, corrections are made 2 ounces at a time. Each time a correction is made, recheck readings to ensure proper charge. For system refrigerant capacity, see REFRIGERANT OIL & REFRIGERANT SPECIFICATIONS article.

REFRIGERANT CHARGE LEVEL

Ensure A/C system has been checked for leaks and evacuated. See EVACUATING A/C SYSTEM and LEAK TESTING . Charge A/C system to specifications. For system refrigerant capacity, see REFRIGERANT OIL & REFRIGERANT SPECIFICATIONS article.

1. If using approved Recovery/Recycling/Charging Center (023-00105 or 023-00150), connect to high-side and low-side service valves. See «SERVICE VALVE LOCATIONS»(ref-118-S16764253362000030700000) under SYSTEM SERVICE VALVES. Operate charging center according to manufacturer's instructions. Charge system with specified amount of refrigerant and refrigerant oil. See REFRIGERANT OIL & REFRIGERANT SPECIFICATIONS article. Check amount of refrigerant oil in system before adding oil. See COMPRESSOR REFRIGERANT OIL CHECKING article.
2. If using manifold gauge set, connect to high-side and low-side service valves. See «SERVICE VALVE LOCATIONS»(ref-118-S16764253362000030700000) under SYSTEM SERVICE VALVES. Connect 2 hoses with shutoff valves to manifold gauge set center port. Connect one hose to vacuum pump and other hose to refrigerant container. Weight of refrigerant container before and after charging can be used to determine amount of refrigerant drawn into system. Using vacuum pump, purge air from center hoses.
3. Fully open manifold gauge set low-side valve and refrigerant container valve to allow refrigerant to enter A/C system. When no more refrigerant is being drawn into A/C system, start engine and allow to idle. Select MAX A/C, set blower motor speed to maximum and allow remaining refrigerant to be drawn into A/C system. NOTE: When ambient air temperature is high, it may be necessary to use an external cooling fan to blow air through condenser and radiator.
4. When proper amount of refrigerant has been added, close refrigerant container valve. Allow any refrigerant remaining in hose to be drawn into A/C system. When low-side pressure decreases to about 30 psi (2.1 kg/cm 2 ), close center valve on manifold gauge set. Ensure A/C system is operating properly. Disconnect manifold gauge set. Install service port caps. Check system for leaks. See «LEAK TESTING»(ref-118-S08729038682000030700000) .

Manufacturer recommends using A/C Refrigerant Recovery, Recycling And Recharging (ACR4) System (J-39500). The ACR4 system has one filtering cycle during recovery plus an automatic multiple pass filtering during evacuation cycle. Follow manufacturer's instructions provided with ACR4 equipment being used.

Connect recovery/recycling equipment, meeting SAE standard J1991 or J2210, to vehicle. Charge A/C system to specifications, using equipment manufacturer's instructions.

Bubble Solution Detector

This is a solution applied externally at suspected leak points. Leaking refrigerant will cause the detector to form bubbles and foam. A soap and water solution also works well.

Dye Solution

This is a colored solution that may be introduced into the A/C system. The dye will show up and color components at leak points. Some manufacturers offer refrigerant containing a Red dye. This dye-containing refrigerant is installed by normal charging procedures. Other dye solutions are visible with a Black light only.

Electronic Leak Detector

This instrument will draw in any leaking refrigerant through a test probe, and then sound an audible signal or create a flashing light if refrigerant is found. It is the most sensitive of the leak detectors used. Leak detectors are sensitive to windshield washing solutions, many solvents and cleaners, and some adhesives. Ensure surfaces near test areas are clean and dry to prevent false signal or detector damage. Liquids ingested into detector will damage detector. (Scheme 24)

Electronic Leak Detector. Scheme 24