SUPPORT-FAN 1941092 - Caterpillar

Service Brakes Seals
(4) Brake actuator piston. (5) Seal.3. Leakage around actuator piston (4) seal in the service brake assembly. This leakage can be caused by incorrect installation or a cut or damaged seal (5).Test
Use the tests that follow to find the cause for brake oil leakage.1. For large amounts of brake oil leakage, inspect all hoses, tubes and fittings in the brake system for an indication of leakage. If any leakage is found, it must be corrected before going to the next step.2. Check the brake oil level in the reservoirs. Measure the distance from the top edge of the reservoir to the oil level. The correct distance is 13 mm (.5 in). If the reservoir is too full, remove oil until it is at the correct level. If the oil level is too low, add oil until it is at the correct level. Install the diaphragm and cover on the reservoir. Use only HYDO OIL.3. Put a clean sheet of plastic or other similar material under the master cylinders to catch brake oil drops from the master cylinders.4. Start the engine and allow the air pressure and oil temperature go up to normal pressure and temperature for operation. Keep the engine in operation during this procedure to make sure of correct air pressure. Make 100 complete brake applications and releases. Stop (pause) ten seconds between applications. Do not move the machine for this test.5. Check the brake oil level in the reservoirs again. If a loss of brake oil can be measured, check the plastic sheet for drops of brake oil. Make a comparison of the amount of oil on the plastic sheet with the amount of oil loss from the reservoir. If the amounts of oil are approximately the same, the problem is in the master cylinder. If the amounts are different, go to the next step.6. If brake oil loss from the reservoir is more than the leakage from the master cylinder, the leakage can be from either or both service brakes on the axle. To find the location of the leakage (if only one brake is leaking), perform the procedure that follows: a. Find which axle has the leakage problem.b. On this axle, disconnect the tube from the brake actuator inlet on one of the service brakes.c. Connect a 6K8076 Inverted Flare Connector to the fitting on the tube. Install a 1/4 inch pipe plug in the connector. One service brake has now been removed from the system so that the other service brake on the axle can be checked for leakage.d. Repeat steps 2 through 5. If brake fluid loss from the reservoir is the same as before, there is no leakage in the brake that has been blocked from the system.e. Repeat steps 6b through 6d on the other brake on the same axle. This gives added proof to the location of the problem.Correction
After the location of the leakage is found, use the procedure that follows to correct brake problems.1. For hose,