A/C Manifold Gauge Set for R744 Air Conditioning Systems

This manifold gauge set is designed for measuring high and low pressure on air conditioning systems using refrigerant R744 (carbon dioxide / CO₂). It is suitable for workshop testing, diagnosis and service work on R744 A/C systems.

The set includes a high-pressure hose, a low-pressure hose and a connection hose for linking to a service unit. The valve block is equipped with piston-type shut-off valves for both the high-pressure and low-pressure sides, allowing controlled operation during pressure measurement and service procedures.

The protected pressure gauges have a diameter of 70 mm and are designed for workshop use. A hanging hook is integrated for convenient positioning during service work.

This manifold gauge set is an ideal replacement for defective gauges on service equipment, but can also be used independently for diagnosing R744 air conditioning systems without a service station.

Technical Data

• Suitable for refrigerant: R744 (carbon dioxide / CO₂)
• Gauge diameter: 70 mm

Low-pressure gauge scale:

• 0 to 1425 PSI
• Resolution: 25 PSI
• 0 to 10 MPa
• Resolution: 0.1 MPa

High-pressure gauge scale:

• 0 to 2250 PSI
• Resolution: 50 PSI
• 0 to 16 MPa
• Resolution: 0.2 MPa

Features

• For measuring high and low pressure on R744 A/C systems
• Includes high-pressure hose, low-pressure hose and service connection hose
• Valve block with piston-type shut-off valves
• Protected pressure gauges with 70 mm diameter
• Hanging hook for workshop use
• Suitable for service equipment replacement or standalone diagnosis

Scope of Delivery

• 1 x manifold gauge set for R744 air conditioning systems
• 1 x high-pressure hose
• 1 x low-pressure hose
• 1 x connection hose for service unit

Functions

• Connect one end of the low-pressure hose to the hose port and the other end to the low-pressure quick coupler.
• Connect one end of the high-pressure hose to the hose port and the other end to the high-pressure quick coupler.
• The valves integrated into the high- and low-pressure couplers control the flow to the pressure gauges. Close both coupler valves by turning them counterclockwise.
• The red high-pressure gauge is connected to the line from the compressor outlet. On R744 air conditioning systems, the high-pressure coupler is standardized and will not fit the low-pressure service port on the vehicle.
• The blue low-pressure gauge is connected to the line to the compressor inlet. On R744 air conditioning systems, the low-pressure coupler is standardized and will not fit the high-pressure service port on the vehicle.
• The high- and low-pressure valves on the manifold control the flow of refrigerant to and from the service unit hose. If no service unit is connected, both manifold valves must be closed by turning them clockwise before connecting the gauge set to the vehicle.
• One of the service hoses is used to connect the manifold gauge set to a refrigerant recovery / service unit. When used together with a service unit, it is required for evacuating and charging R744 air conditioning systems.
• General instructions for A/C service can be found in the service unit manual. Specific procedures for individual system and vehicle model types should always be taken from the vehicle manufacturer’s A/C service manual.

Pressure Test

Preparation

• Close the high- and low-pressure manifold valves by turning them clockwise.
• Close the valves on the high- and low-pressure couplers by turning them counterclockwise.

Connecting the Hoses

• Connect the service hoses as described under Functions.

Connecting the Couplers

• Attach the high-pressure coupler to the high-pressure service port of the air conditioning system.
• Attach the low-pressure coupler to the low-pressure service port of the air conditioning system.

Performing the Test

• Start the vehicle, allow it to reach normal operating temperature, and switch on the air conditioning system.
• Open the valves on the high- and low-pressure couplers by turning them clockwise.
• Read the pressure values on both gauges and compare them with the values specified by the vehicle manufacturer.

After the Test

• Switch off the air conditioning system.
• Close the valves on the high- and low-pressure couplers by turning them counterclockwise.
• Disconnect the high- and low-pressure couplers from the air conditioning system by pulling the knurled release ring on both couplers.