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Compressor, Reservoir, Regulator

  1. With assembly removed from vehicle, but not disassembled, connect test set to regulator and inflate reservoir to 80-110 psi. Route a rubber hose between vacuum and vent ports.
    CAUTION: Do not submerge assembly completely or water will enter around cover gasket.

    Check for air leaks. Remove hose from vacuum port and put disconnected end in water. Cover vacuum port with finger. If bubbles are present, second stage housing check valve is probably faulty.

  2. Place assembly vertically in a tub of water until diaphragm is just submerged.
    Fig 1: Compressor, Reservoir, Regulator Assembly
    G09347743Courtesy of GENERAL MOTORS COMPANY
  3. If compressor passes leak test but fails output test, overhaul compressor.
  4. If delay is still not within specifications, and if fluid level is satisfactory, replace height control valve.