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Home >> Chevrolet >> 2002 >> Blazer 4D Utility, 4WD, Part Time >> Repair and Diagnosis >> External Pages >> Different car >> Section 1327 (Automatic Transmission - Mu4 (Introduction, Service & Replacement)) >> Diagnostic Information and Procedures >> Line Pressure Check Procedure >> Evaluation

Line Pressure Check Procedure: Evaluation

WARNING: This page is about a different car, the 2004 Pontiac Vibe. However, it is still accessible from the selected car via links, so may be relevant.

Compare the line pressure test results with the Line Pressure Results in the following table. If the line pressure is not as specified, refer to the Line Pressure Test Diagnosis for further evaluation.

Line Pressure Results

Engine Running at R Range Line Pressure D, 2, L Range Line Pressure
Idle Speed (600-700 RPM) 647-760 kPa (94 -111 psi 382 -422 kPa (55-61 psi)
Stall Speed (2400-2700 RPM) 1,520-1,755 kPa (220-254 psi 713-844 kPa (103-122 psi)
Line Pressure Test Diagnosis

Line Pressure Measurement Probable Cause
Higher than Specification in Drive (D) and Reverse (R) Ranges
  • Pressure regulator valve malfunction
  • Throttle valve malfunction
  • Out of adjustment accelerator
Lower than Specification in Drive (D) and Reverse (R) Ranges
  • Fluid pump malfunction
  • Pressure regulator valve malfunction
  • Throttle valve malfunction
  • Out of adjustment accelerator cable
Lower than Specification in Drive (D) Range Only
  • Forward clutch fluid circuit leak
  • Drive (D) range fluid circuit leak
Lower than Specification in Reverse (R) Range Only
  • Direct clutch fluid circuit leak
  • 1st-reverse brake fluid circuit leak
  • Reverse (R) range fluid circuit leak