Document 82JYXo8Ko7mnL5vbQXJEkpyR5

LESSON ONE-MODULE 1 BRAKE SYSTEM DIAGNOSIS AND TESTING Master Cylinder Compensator Port Test The master cylinder compensating port test is used to check for open compensating ports in the master cylinder. This test should be performed if you suspect that the brake master cylinder is failing to return to the fully released position, leaving the brakes partially applied. The symptoms of a vehicle with partially applied brakes include overheating and premature lining wear. Perform the following test to determine if the master cylinder compensat ing ports are open: Remove the cover from the master cylinder. Observe the brake fluid reservoirs while an assistant pumps the brake pedal. A small squirt or geyser should appear in the reservoirs as the brakes are applied. If there is no turbulence, loosen the nuts securing the master cylinder to the power booster about 6.35 mm (1/4 in) and pull the master cylinder away from the power booster. Hold the master cylinder in this position and repeat the previous step. - If turbulence now occurs, check booster operation. - If turbulence still does not occur, replace the master cylinder. 6 September, 2005 Brake System Diagnosis and Repair