PLATE 1533715 - Caterpillar

Illustration 1 g00995884
Components for air system and brakes (A) Tractor (B) Scraper (AA) Standard air lines (BB) Attachment (CC) Division between the wheel tractor and the scraper (1) Main air relief valve (2) Reserve air tank (3) Dry air tank (4) Wet air tank (5) Air horn (6) Air dryer (7) Air compressor (8) Air horn solenoid valve (9) Lockup clutch solenoid valve (10) Parking brake control valve (11) Air compressor governor (12) Differential lock control valve (13) Secondary brake control valve (14) Secondary pilot valve (15) Air pressure gauge (16) Air block (17) Seat suspension (18) Brake control valve (19) Lockup clutch selector valve (20) Parking brake chamber (21) Differential lock (22) Double check valve (23) Relay valve (24) Differential (25) Brake housing assemblies (26) Scraper relay valve (27) Air tank All of the brakes in the brake system are shoe type brakes. There is a brake at each wheel of the tractor and the scraper. The wheel tractor is equipped with a parking brake. The parking brake is located on the output shaft of the output transfer gear group. The service brakes are activated by air pressure in the brake housing assemblies (25). The parking brake is activated by a spring in parking brake chamber (20). The brake housing assemblies (25) and parking brake chamber (20) provide the machine with the following three types of brakes:
Service
Secondary
ParkingThe air compressor (7) supplies the air to the air tanks of the wheel tractor: (2), (3) and (4). The flow of air is divided into the following four separate circuits:
Service brake
Parking
Secondary brake
Accessory circuitsRefer to Systems Operation, "Brake System" for more information on the brake system.Accessory Circuits
Pressurized air for the accessory air circuits goes from air compressor (7) to air block (16). Pressurized air is directed from air block (16) to four locations:
Parking brake control valve (10)
Secondary brake control valve (13)
Air pressure gauge (15)
Seat suspension (17) Air also flows from reserve air tank (2) to the following locations:
Air horn solenoid valve (8)
Lockup clutch solenoid valve (9) Solenoid valve (8) is activated by the horn button inside the cab. Valve (8) directs air flow to air horns (5). Solenoid valve (9) directs air flow to lockup clutch selector valve (19). Selector valve (19) engages the lockup clutch in the torque converter.The differential lock control valve (12) gets air flow from brake control valve (18). When differential lock control valve (12) is depressed, pressurized air is sent to the differential lock (21). The differential lock is located inside the differential (24) .Pressure Protection Valve
Illustration 2 g01044634
(28) Supply port (29) Valve spool (30) Delivery portAll air flow to the accessory air circuits must pass through the pressure protection valve. No air will flow through the pressure protection valve until spool (29) raises. As spool (29) raises, air is allowed to pass through the pressure protection valve and out delivery port (30) .