VALVE 0545565 - Caterpillar

ILLUSTRATION A
ILLUSTRATION B4. Observe the marking on the gauge rod. If the machined groove on the rod is covered by the outer boss (as in Illustration A), the wheel brakes are worn and will need repair. If the machined groove is visible (Illustration B), the wheel brake disc wear is within tolerance. If breakage of pin (3) or spring (4) is suspected, remove each plug (2) and check for correct movement using the measurement tool. The removal of any of the lower plugs will cause loss of oil in the axle housing. If one wheel brake is found to have disc wear, both of the wheel brake assemblies on that axle must be overhauled.
Excessive brake wear may result in loss of braking.
Slack Adjuster Checks
SMCS CODE: 4261-535
SLACK ADJUSTER COMPONENTS
(1) Housing. (2) Large piston. (3) Orifice. (4) Small piston.When a slack adjuster operates (strokes) correctly, there is always a small amount of pressure on the piston in the service brakes after the brakes are released. A failure (incorrect stroking) in a slack adjuster may cause a loss in brake performance.Use this procedure to check for a failure in a slack adjuster:1. Start the engine and build up brake oil pressure. Ensure there is enough oil in the system throughout this procedure.2. Push the brake pedal to apply the brakes.3. Release the brakes and immediately open one of the bleed valves on one of the wheel brake groups.4. If oil comes out with pressure, the slack adjuster on that side is stroking correctly.5. Perform Steps 1 through 4 for the wheel brake on the other side wheel group.6. If oil comes out with pressure, the slack adjuster for that side is stroking correctly. Repeat this procedure on the other axle.7. If there is no pressure from one or more of the sides, there is a failure in the slack adjuster piston or there is a bad leak at the brake piston seals.8. Remove the slack adjuster that may have a failure.
CHECK OF SMALL PISTON MOVEMENT
(2) Large piston. (5) Rod.9. Disassemble and check the slack adjuster as follows:a. Remove large piston (2) from housing (1).b. Install a 6.35 mm (.250 in.) diameter by 31.8 mm (1.25 in) long rod (5) into orifice (3) of large piston (2) as shown.c. Use an 8S2263 Valve Spring Tester to check the movement of small piston (4).d. Put large piston (2) in the spring tester and put a force on rod (5) as shown.e. If 220 N (50 lb.) of force on rod (5) does not cause small piston (4) to move, replace the complete piston assembly.
CHECK OF LEAKAGE AROUND SMALL PISTON
(2) Large piston.f. Check small piston (4) for low pressure leakage. Install an FT834 Clutch Testing Nozzle as shown, and put large piston (2) in a container of water. Apply low air pressure through orifice (3).g. If any air bubbles come out from the bottom side of the piston, make a replacement of the complete piston assembly.10. If the slack adjuster is not damaged, check