Initial Inspection and Diagnostic Overview
PERFORMANCE TEST1. Install the manifold gauge set.
2. Run the engine at 2,000 rpm and set the controls for maximum cooling and high blower speed.
3. Keep all windows and doors open.
4. Place a dry-bulb thermometer in the cool air outlet.
5. Place a wet-dry thermometer close to the inlet of the cooling unit.
6. Check that the reading on the high pressure gauge is 1,373 - 1,575 kPa (14 - 16 kg/sq.cm, 199 - 228 psi). If the reading is too high, pour water on the condenser. If the reading to too low, cover the front of the condenser.
7. Check that the reading on the dry-bulb thermometer at the air inlet at 25 - 35 °C (77 - 95 °F).
8. Calculate the relative humidity from the psychrometric graph by comparing the wet-and dry-bulb reading at the air inlet.
9. Measure the dry-bulb temperature at the cool air outlet, and calculate the difference between the inlet dry-bulb and outlet dry-bulb temperatures.
10. Check that the intersection of the relative humidity and temperature difference falls within the block. If the intersection is within the block, cooling performance is satisfactory.