Automotive Heating + Air-Conditioning Tools

The repair and diagnostic tools for the heating, ventilation, and air-conditioning (A/C) systems are discussed in the following paragraphs. This discussion does not cover all of the tools you may need; rather, these tools are the most commonly used by the ser vice industry. Details of when and how to use these tools are covered in here.

Manifold Gauge Set

A manifold gauge set is used when discharging, charging, evacuating, and for diagnosing trouble in an A/C system. With the new legislation on handling refrigerants, all gauge sets are required to have a valve device to close off the end of the hose so that the fitting not in use is automatically shut.

The low-pressure gauge is graduated into pounds of pressure from 1 to 120 (with cushion to 250) in 1-pound graduations, and, in the opposite direction, in inches of vacuum from 0 to 30. This is the gauge that should always be used in checking pressure on the low-pressure side of the system. The high-pressure gauge is graduated from 0 to 500 pounds pressure in 10-pound graduations. This gauge is used for checking pressure on the high-pressure side of the system.

The gauge manifold is designed to control refrigerant flow. When the manifold test set is connected into the system, pressure is registered on both gauges at all times.

Because R-134a is not interchangeable with R-12, separate sets of hoses, gauges, and other equipment are required to service vehicles. All equipment used to service R-134a and R-12 systems must meet SAE standard J1991. The service hoses on the manifold gauge set must have manual or automatic backflow valves at the service port connector ends to prevent the refrigerant from being released into the atmosphere during connection and disconnection. Mani fold gauge sets for R-134a can be identified by labels on the gauges and/or have a light blue color on the face of the gauges.

For identification purposes, R-134a service hoses must have a black stripe along their length and be clearly labeled. The low-pressure hose is blue with a black stripe. The high-pressure hose is red with black stripe and the center service hose is yellow with a black stripe. Service hoses for one type of refrigerant won’t easily connect into the wrong system, as the fittings for an R-134a system are different than those used in an R-12 system.

++++An A/C port adapter set. SPX Service Solutions

++++ With a fluorescent tracer system, refrigerant leaks will glow brightly when inspected with a UV/Blue light as a luminous yellow-green. Tracer Products

++++ An electronic leak detector. SPX Service Solutions

++++A refrigerant identifier (analyzer).

Service Port Adapter Set

To connect a manifold gauge set to an A/C system, adapters are sometimes needed. The high-side fitting on many vehicles with an R-12 sys tem may require the use of a special adapter to connect the manifold gauge set to the service port. The service hoses of some manifold gauge sets are not equipped with a Schrader valve-depressing pin.

Therefore, when connecting this type hose to a Schrader valve, an adapter must be used. The manifold and gauge sets for R-12 and R-134a are not interchangeable; therefore, there are no suitable adapters for using R-12 gauges on an R-1134a system or vice versa.

Electronic Leak Detector

An electronic leak detector is safe and effective and can be used with all types of refrigerants.

A hand-held battery-operated electronic leak detector contains a test probe that is moved about 1 inch per second in areas of suspected leaks. Since refrigerant is heavier than air, the probe should be positioned below the test point. An alarm or a buzzer on the detector indicates the presence of a leak. On some models, a light flashes when refrigerant is detected.

Fluorescent Leak Tracer

To find a refrigerant leak using the fluorescent tracer system, first introduce a fluorescent dye into the air-conditioning system with a special infuser included with the detector equipment. Run the air conditioner for a few minutes, giving the tracer dye fluid time to circulate and penetrate. Wear the tracer protective goggles and scan the system with a black-light glow gun. Leaks in the system will shine under the black light as a luminous yellow-green.

++++ A dual (R-12 and R-134a) charging station. RTI Technologies, Inc.

++++A single-pass refrigerant recovery and recycling machine. RTI Technologies, Inc.

++++A dial-type thermometer used to check A/C operation. SPX Service Solutions

Refrigerant Identifier

A refrigerant identifier is used to identify the type of refrigerant present in a system. This test should be done before any service work. The tester is used to identify the purity and quality of the refrigerant sample taken from the system.

Refrigerant Recycling/Charging Stations

A charging station removes, evacuates, and recharges an A/C system. The amount of refrigerant put into the system is adjusted through controls on the station.

Special equipment is used to remove and recycle the refrigerant in a system. These machines draw the old refrigerant out of the system, filter it, separate the oil, remove moisture and air, and store the refrigerant for future use.

All recycled refrigerant must be safely stored in DOT CFR Title 49 or UL-approved containers. Before recycled refrigerant can be used, it must be checked for non-condensable gases.

Thermometer

A digital readout or dial-type thermometer is often used to measure the air temperature at the vent outlets, which indicates the overall performance of the system. The thermometer can also be used to check the temperature of refrigerant lines, hoses, and components while diagnosing a sys tem. While doing the latter, an electronic pyrometer works best and is often used.

Compressor Tools

Although compressors are usually replaced when they are faulty, certain service procedures for them are standard practice. Most of these procedures focus on compressor clutch and shaft seal service and they require special tools. Clutch plate tools are required to gain access to the shaft seal. They are also needed to reinstall the clutch plate after service.

Many different tools are required to perform these services to a compressor. Typically to replace a shaft seal, you will need an adjustable or fixed spanner wrench, clutch plate installer/remover, ceramic seal installer/remover, seal assembly installer/remover, seal seat installer/remover, shaft seal protector, snap ring pliers, O-ring remover, and O-ring installer. Some of these tools are for a specific model compressor; others are universal fit or have interchangeable parts to allow them to work on a variety of compressors.

Hose and Fitting Tools

An A/C system is a closed system, meaning outside air should never enter the system and the refrigerant in the system should never exit to the outside. To maintain this closed system, special fittings and hoses are used. Often, special tools, such as the spring-lock coupling tool set, are required when servicing the system's fittings and hoses. Without this tool, it’s impossible to separate the connector and not damage it.

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