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Line Pressure Test

Fig 1: Identifying Transmission Fluid Drain Plug And Line Pressure Tap
G06067653Courtesy of FORD MOTOR CO.
Item Part Number Description
1 7A010 Line pressure tap
2 7A010 Transmission fluid drain plug
NOTE: Carry out the LINE PRESSURE TEST  prior to carrying out the Stall Speed Test. If the line pressure is low at stall, do not carry out the STALL SPEED TEST  or further transaxle damage will occur. Do not maintain Wide Open Throttle (WOT) in any transaxle range for more than 5 seconds.
NOTE: Do not mistake the transmission fluid drain plug for the line pressure tap plug or the transmission fluid will have to be refilled.

This test verifies that the line pressure is within specification.

  1. Connect the Transmission Fluid Pressure Gauge to the line pressure tap.
  2. Start the engine and check the line pressures see the line pressure chart  to determine if the line pressure is within specification.
    LINE PRESSURE CHART

    Gear Line
    Pressures at Idle (1)
    P 303-483 kPa (44-70 psi)
    R 621-793 kPa (90-115 psi)
    N 303-483 kPa (44-70 psi)
    D 510-669 kPa (74-97 psi)
    L 483-689 kPa (70-100 psi)
    Pressure at Wide Open Throttle (WOT) Stall (1)
    P 303-483 kPa (44-70 psi)
    R 1, 655-2, 137 kPa (240-310 psi)
    N 303-483 kPa (44-70 psi)
    D 1, 586-1, 793 kPa (230-260 psi)
    L 1, 586-1, 793 kPa (230-260 psi)
    (1) All pressures are approximate.
  3. If the line pressure is not within specification, GO to PINPOINT TEST A  to diagnose the Line Pressure Control (LPC) operation. If LPC operation is OK, see the Line Pressure Diagnosis Chart  for line pressure concern causes.
  4. When the pressure tests are completed, install the line pressure tap plug.
    • Tighten to 9 Nm (80 lb-in).
    LINE PRESSURE DIAGNOSIS CHART

    Test Results Possible Source
    HIGH at IDLE - ALL RANGES Wiring Harnesses Line Pressure Control (LPC) Solenoid Main Regulator Valve
    LOW at IDLE - ALL RANGES Low Fluid Level Fluid Inlet Filter/Seal Main Control Body Cross Leaks Gaskets Pump Separator Plate
    LOW in Park ONLY Valve Body
    LOW in Reverse ONLY Separator Plate Reverse Clutch Valve Body Forward Clutch
    LOW in Neutral ONLY Valve Body
    LOW in O/D ONLY Forward Clutch Valve Body
    LOW in Drive ONLY Forward Clutch
    LOW in Manual 1st ONLY Forward Clutch Valve Body