MasterCool 89660 User Manual

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OPERATING INSTRUCTIONS
PROFESSIONAL R134a MANIFOLD GAUGE SET
PART #89660
WARNING
Wear Safety Goggles
Avoid Contact with Refrigerant
R134a TEMPERATURE PRESSURE CHART
Ambient Temp (˚F) Low Side Gauge High Side Gauge
65˚ 25-35 psi 135-155 psi
70˚ 35-40 psi 145-160 psi
75˚ 35-45 psi 150-170 psi
80˚ 40-50 psi 175-210 psi
85˚ 45-55 psi 225-250 psi
90˚ 45-55 psi 250-270 psi
95˚ 50-55 psi 275-300 psi
100˚ 50-55 psi 315-325 psi
105˚ 50-55 psi 340-345 psi
TROUBLESHOOTING TIPS
• Low side and high side pressure are low.
Usually indicates a low charge.
• Low side pressure is low and high side pressure is high.
Usually indicates a blockage in the system. (i.e. expansion of valve or orifice tube.)
• Low side pressure is high and high side pressure is low.
When accompanied by a vibrating gauge needle, usually indicates faulty reed valves in compressor.
• Low side and high side pressures are high.
Usually indicates an over charged system.
HOOK-UP FOR SYSTEM DIAGNOSIS:
• Verify that service ports are clean and free of metal shavings.
• Verify that both valves on the manifold are shut completely.
• Connect blue adapter to low side service port (5).
• Connect red adapter to high side service port (4).
• Start engine. Turn A/C mode selector to HIGH and fan to HIGH.
• Observe pressure on the manifold gauges and refer to your automotive manual for proper diagnosis.
CHARGING REFRIGERANT:
a. Verify that both valves on the manifold are shut completely.

MasterCool 89660 Specifications

General

Model	89660
Category	Measuring Instruments
Display	LCD
Battery	9V
Type	Digital Manifold
Refrigerant Type	R-22, R-134a, R-404A

Summary

Safety Precautions

Wear Safety Goggles

Always wear safety goggles when operating the equipment to protect your eyes from potential hazards.

Avoid Contact with Refrigerant

Take necessary precautions to avoid direct contact with refrigerant to prevent skin or eye injury.

Troubleshooting Tips

Low Side and High Side Pressure Low

Indicates a low charge in the system.

Low Side Pressure Low, High Side Pressure High

Typically signifies a blockage within the system, such as an expansion valve or orifice tube.

Low Side Pressure High, High Side Pressure Low

When accompanied by a vibrating gauge needle, suggests faulty compressor reed valves.

Low Side and High Side Pressures High

Generally indicates that the system is overcharged.

Hook-up for System Diagnosis

Verify Service Ports

Ensure service ports are clean and free of metal shavings before connecting.

Verify Manifold Valves

Confirm that both valves on the manifold gauge set are shut completely prior to hook-up.

Connect Adapters

Connect the blue adapter to the low side service port and the red adapter to the high side service port.

Start Engine and Set Controls

Start the engine and set the A/C mode selector to HIGH and fan to HIGH for diagnosis.

Charging Refrigerant

Close Manifold Valves

Verify that both manifold valves are shut completely before charging.

Connect Refrigerant Supply

Connect the yellow hose to the refrigerant gas supply, following manufacturer instructions.

Charge System Safely

Slowly open the low side valve until pressure reaches 40 psi, do not exceed this limit.

Finalize Charging

Close the low side (blue) valve when charging is finished.

Evacuation and Leak Testing

Verify System Empty

Ensure there is no refrigerant remaining in the A/C system before evacuation.

Connect Vacuum Pump

Attach adapters to the system, connect the yellow hose to the vacuum pump, and turn it on.

Evacuate System

Open both low and high side manifold valves to evacuate the system.

Run Vacuum Pump

After reaching 29" Hg vacuum, run the pump for an additional 20 minutes.

Verify Vacuum Retention

Close both manifold valves and check gauges to ensure the vacuum remains.

System Schematic Components

Low Side Hose/Adapter

Identified as component 1 in the system schematic.

High Side Hose/Adapter

Identified as component 2 in the system schematic.

Service Hose

Identified as component 3 (yellow) in the system schematic.

Compressor Discharge Valve

Identified as component 4 (16mm diameter) in the system schematic.

Compressor Suction Valve

Identified as component 5 (13mm diameter) in the system schematic.