Usage:
773 (63G1-1283)
This instruction gives the procedure for installing a spring engaged, air pressure disengaged parking brake control. This parking brake control puts more force on the parking brake lever than the former mechanical parking brake control. See the instructions that follow for installation.
(1) Raise the body and install FT965 Cylinder Support (1). Put blocks in front of and behind the truck wheels. Release the parking brake. Remove drive shaft guard (2), disconnect cable (3), spring (4) and bracket (5). Disconnect the driveshaft at the transmission yoke.
(2) Remove the parking brake assembly.
(3) Remove the old lever and install 2G1678 Lever (6) with the lever approximately 23° above the horizontal plane.
NOTE: Clean the holes in the transfer gear cover with a tap where the new rotochamber bracket will be installed (see step 7).
(4) Measure the drum and brake shoes for wear. The outer surface of the shoes must be at least .03" (0.8) above the rivet heads. The drum I.D. (inner diameter) must not be machined larger than 12.090" (307.09). A worn drum must not have an I.D. larger than 12.180" (309.37).
(5) Install the parking brake assembly. Check the angle of the lever. If it is not approximately 23° above the horizontal plane, remove the brake assembly, adjust the angle of the lever and install the brake assembly.
(6) Install bottom plate (7) to 2G2030 Rotochamber (8) with 1B4206 Nuts (9) and lockwashers. Install 5H4778 Union (10) to the rotochamber. Install 9D8632 Rod End (11) and 9S1354 Nut (12) on the rotochamber shaft. Do not tighten the nut.
(7) Install the bracket to the transfer gear cover. Install rotochamber (8) to bracket (13) with 1B4206 Nuts and lockwashers. Pull bellows (14) through the hole in the bracket so that the bellows is not held between the rotochamber and the bracket.
(8) Put air pressure to the rotochamber before the pin is installed so that the rotochamber shaft moves all the way up. Adjust the rod end with the brake lever in the OFF position so that the hole in the rod end is in alignment with the hole in the lever. Install 3H1977 Pin (15) and 3B4615 Cotter Pin.
(9) Install 2G2643 Bracket (16) to the transfer gear cover. Install 5D470 Valve (17) to the bracket with 2B2695 Bolts (18), 1D4716 Nuts and lockwashers. Install 5M6213 Plug (19), 4J3914 Union (20) and 4S6667 Hose Assembly (21). Connect hose (21) to union (10).
(10) Remove lever (22) and cable (3). Assemble 5D4382 Valve (23), 4S7606 Union (24) and 4D2560 Union (25) to 2G2845 Lever (26). Adjust the valve so that the valve plunger is completely in when the lever is in the OFF position. Also, the valve plunger should be completely out when the lever is in the ON position.
(11) For Trucks 63G1-63G670 and 80S1-80S54, disconnect 5D7464 Hose and 3D7587 Union (27) from the delivery port of pressure protection valve (28) which is on cab front support (29). Install 3L6521 Tee (30) to valve (28). Install 3D7587 Union (27) and hose, and 4D6243 Hose (31) to tee (30). Put hose (31) through the hole in the cab where the parking brake cable was removed. Connect hose (31) to union (25). Install 5D5886 Hose (32) to union (24). Install lever (26) to the console.
(12) For Trucks 63G671-63G1283, 11S1-11S181 and 80S55-80S57, disconnect 5J7585 Hose (33) and 4D577 Union-90° at 6D7639 Service Tee (34). Remove the 4D577 Union. Install 3B7722 Bushing in tee (34) where the 4D577 Union was removed. Install 4S7563 Hose (35) from union (25) to the 3B7722 Bushing. Disconnect hose (36) at tee (34). Install 7J5996 Tee (37) to tee (34). Connect hoses (33) and (36) to tee (37). Install 5D5886 Hose (32) to union (24). Install lever (26) to the console.
(13) Put hose (32) through the hole in the cab floor. Connect hose (32) to 2J4211 Adapter (38) and 6D8079 Hose (39). Fasten the hoses with 9M8406 Clips (40). Connect hose (39) to union (20).
(14) Install the driveshaft and driveshaft guard. Start the engine and let air pressure fill the system. Put the control lever in the OFF position; the rotochamber should move up and cause the parking brake to release. Put the control lever in the ON position; the rotochamber shaft should move down and cause the parking brake to engage. Stop the engine.