BASE PLATE 6R1490 - Caterpillar

1. Mark the location of all hoses (3) connected to brake control valve (1). Disconnect hoses (3) from brake control valve (1), and put protective caps on them.2. Remove four bolts (2) and brake control valve (1) from the machine.3. Put brake control valve (1) in position on the machine as shown. Install four bolts (2) that hold the brake control valve in position.4. Connect all hoses (3) to brake control valve (1).5. Remove the air from (bleed) the brake system. See Testing And Adjusting for additional information.Disassemble Brake Control Valve
START BY:a. remove brake control valve 1. Remove the fittings from the brake control valve if necessary.2. Remove four bolts (2), retainer (3) and plate (1) from the brake control valve.3. Remove the diaphragm from plate (1). 4. Remove piston (4) and adapter (5) from the valve body.5. Remove the lip-type seal from adapter (5). 6. Remove spool (8) and spring (7) from the valve body.7. Remove relief valve (6) from the valve body. 8. Disassemble the relief valve as follows:a. Remove O-ring seals (9) and (10) from body (11).b. Remove plug (15) from body (11). Remove shims (13) and O-ring seal (14) from plug (15).c. Remove spring (17), dowel (12) and valve (16) from body (11). 9. Remove plug (18). Remove the O-ring seal from plug (19).10. Remove check valve (18) from the valve body. 11. Disassemble the check valve as follows:a. Remove O-ring seals (20) and (21) from body (22).b. Remove plug (25) from body (22), and remove O-ring seal (24) from the plug.c. Remove spring (27), dowel (23) and valve (26) from body (22).Assemble Brake Control Valve
1. Assemble the check valve as follows:a. Put valve (4), dowel (5) and spring (6) in position in body (3).b. Put O-ring seal (7) on plug (8), and install plug (8) in body (3).c. Install O-ring seals (1) and (2) on body (3). 2. Put clean oil on the O-ring seals, and install check valve (9) in valve body (10).3. Put clean oil on the O-ring seal, and put the O-ring seal in position on plug (11). Install plug (11) in valve body (10). 4. Assemble the relief valve as follows:a. Put valve (14), dowel (15) and spring (16) in position in body (20).b. Put O-ring seal (18) on plug (19). Put shims (17) in plug (19), and install plug (19) in body (20).c. Put O-ring seals (12) and (13) in position on body (20). 5. Put clean oil on the O-ring seals, and install relief valve (21) in valve body (10).6. Put spring (22) and spool (23) in position in valve body (10) as shown. 7. Use tool (A) to install lip-type seal (24) in adapter (25). Install the seal with the lip as shown and until it bottoms in the counterbore of the adapter. 8. Put O-ring seal (26) in position in adapter (25).9. Put clean oil on the lip-type seal in adapter (25), and put the adapter in position over the spool in valve body (10).