PISTON AS 1N4269 - Caterpillar

Move steering frame lock to the LOCKED position.
Stop the engine. Engage the parking brake. Test Procedure
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End View of Axle Housing for the Service Brakes
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View A-A
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Detail B (1) Piston. (2) Friction disc. (3) Pin. (4) Plug. (5) Screw. (6) Cup. (7) Flange face for the axle housing.Note: The following steps require accumulator pressure for the service brakes.
Start the engine. Run the engine until the brake accumulators reach the cutout pressure (less than 30 seconds).
Stop the engine. Engage the parking brake.
Thoroughly clean the area around plug (4). Remove any excess paint that may be present on the flange face for the axle housing (7). Plug (4) is held in place by screw (5) .
Remove screw (5) and plug (4) .
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(1) Piston. (2) Friction disc. (3) Pin. (6) Cup. (7) Flange face for the axle housing. (8) Depth micrometer. (9) Gauge block. (C) Dimension that is used to determine the amount of service life of a brake disc. (D) Thickness of gauge block (9). (E) Total distance of the depth micrometer.
Apply light pressure to pin (3) in order to ensure that pin (3) is seated against cup (6) .
Measure dimension (C) with the service brakes in the APPLIED position. Dimension (C) equals the distance from the flange face for axle housing (7) to the end of pin (3). Use a depth micrometer and the tools in Table 1 to measure dimension (C) .
Use a caliper or a similar tool to measure the exact thickness (D) of gauge block (9) .
Gauge block (9) is in the shape of the letter "U". Position gauge block (9) so that the slot straddles the hole in flange face (7). Firmly hold gauge block (9) against flange face (7) .
Measure dimension (E) .
To determine the value of dimension (C), subtract the value of dimension (D) from the value of dimension (E) .Note: If gauge block (9) is not available, use a depth micrometer with a half of a base. Shorten the base on the micrometer by grinding. The grinding will help allow the base of the micrometer to rest on flange face (7). Measure dimension (C) directly from flange face (7) .
Record the measurements on a piece of paper for each brake that contains a new brake disc. Also, record the number of service hours that are shown on the service meter unit (SMU).Note: The baseline value for dimension (C) must be recorded electronically on the machines transmission ECM. Use the Caterpillar electronic technician (ET) in order to record the value of dimension (C) .
Use the ET software to record the baseline value for dimension (C) from the transmission ECM.
Stop the engine.
Connect ET to diagnostic connector (10). Diagnostic connector for ET is behind and to the left of the seat.
Turn the engine start switch key to the ON position, but do not start the engine.
Start the ET software and select "Transmission" for the model of machine that is being serviced.
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Select the "Configuration Tool" icon.
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Note: Record a new baseline value ONLY