Mazda MX-5 NA silhouetteMX-5 NA

AIR CONDITIONER

U-28prose procedure
Continued from U-27

Installation of manifold gauge set

Installation of manifold gauge set

  1. 1
    Close both hand valves of the manifold gauge set.
    Manifold gauge set installed on the vehicle's A/C service ports. Shows the LOW (left) and HIGH (right) gauges with their colour-coded service hoses connected to the low- and high-pressure pipe fittings in the engine bay.
    05U0UX-091
  2. 2
    Connect the low-pressure hose to the low-pressure gauge fitting and high-pressure hose to the high-pressure gauge fitting.
  3. 3
    Tighten the hose nuts by hand only.

Leak test

After evacuating the system (refer to page U-29), check for leaks.

Leak test

  1. 1
    Connect a full refrigerant container to the service valve.
    Refrigerant container with the service valve and hose routed through to the manifold gauge set installed on the vehicle for the leak-test charge step.
    05U0UX-046
  2. 2
    Open the high-pressure manual valve to charge the system with refrigerant gas.
  3. 3
    When the low-pressure gauge reads 98 kPa (1 kg/cm2, 14 psi), close the high-pressure manual valve.
  4. 4
    Use a gas leak detector to check the system for leaks. If a leak is found, repair the faulty component or connection; then evacuate the system again.
    Halide gas leak detector — handheld unit with the sensing wand attached by a flexible hose. Used to check the system for refrigerant leaks per step 4.
    05U0UX-092

Discharging

  1. 1
    Connect the manifold gauge set to the refrigeration system.
  2. 2
    Place the free end of the center hose on a shop towel.
    Manifold gauge set with the discharge centre hose routed onto a shop towel. CLOSE label is on the low-pressure (left) valve, OPEN label on the high-pressure (right) valve. Callouts identify the low-pressure and high-pressure gauge fittings.
    05U0UX-093
  3. 3
    Slowly open the high-pressure manual valve to allow the refrigerant to escape.
    Open the valve only slightly. If refrigerant is allowed to escape too fast, the compressor oil will be drawn out of the system.
  4. 4
    Check the shop towel to make sure no oil is being discharged. If oil is present, partially close the manual valve.
  5. 5
    After the manifold gauge reading drops below 343 kPa (3.5 kg/cm2, 50 psi), slowly open the low-pressure manual valve.
    Close-up of the manifold gauge set body with the high- and low-pressure gauge faces and the two hand-valves below them. Illustrates the gauge being read during discharging in steps 5 and 6.
    05U0UX-094
  6. 6
    As the system pressure drops, gradually open both the high- and low-pressure manual valves until both gauges show 0 kPa (0 kg/cm2, 0 psi).
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