Operation CHARM: Car repair manuals for everyone.
Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la or lemon-manuals.org.ua

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Expansion Valve: Testing and Inspection

1. CHECK QUANTITY OF GAS DURING REFRIGERATION CYCLE
2. SET ON MANIFOLD GAUGE SET

3. RUN ENGINE
Run the engine at 1,500 rpm for at least 5 minutes.
Then check that the high pressure reading is 1.37 - 1.53 MPa (14 - 16 kg/sq.cm, 199 - 228 psi).

4. CHECK EXPANSION VALVE
If the expansion valve is faulty, the low pressure reading will drop to 0 kPa (0 kg/sq.cm, 0 psi), otherwise it is OK.

HINT: When the low pressure drops to 0 kPa (0 kg/sq.cm, 0 psi), check the receiver's IN and OUT side for no temperature difference.