Mazda MX-5 1990 Workshop Manual page 757

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TROUBLESHOOTING GUIDE
Case 1: Insufficient refrigerant
Measured pressure
Low-pressure side: Less than 78.5 kPa (0.8 kg/cm
2
,
11.4 psi)
High-pressure side: 785-883 kPa (8-9 kg/cm
2
,
114-128 psi)
Condition
• Outlet air from vents not cold.
• Bubbles seen in sight glass.
Step 1
1 . Check for oil stains on the pipes, hoses and other parts. (Refer to illustration below.)
2. If oil staining is found at the connection of pipes or hoses, replace the O-ring; then, evacuate, charge,
and test the system.
3. If oil staining is not found, go to Step 2.
05UOUX-023
Step 2
1. Check for leakage from the following connections with a gas leak tester.
• Inlet and outlet of condenser.
• Inlet and outlet of receiver/drier.
• Inlet and outlet of compressor.
• Sight glass.
• Inlet and outlet of cooling unit.
2. If leakage is evident, go to Step 3.
3. If leakage cannot be found, evacuate, charge, and test the system. (System OK, but refrigerant leaked
gradually over time.)
Step 3
1. Check tightening torque of the connection where leak was detected.
2. If the connection is loose, tighten the connection to the specified torque; then evacuate, charge, and test
the system.
3. If the connection is properly tightened, replace the O-ring; then evacuate, charge, and test the system.
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