SWITCH AS-LIQUID LEVEL 1741821 - Caterpillar

Illustration 1 g00562513
Suspension and Support Axle (1) Support axle (2) Rear major bogie arm (3) Front major bogie arm (4) Front minor bogie arm (5) Rear minor bogie arm (6) Air spring (7) MidrollersSupport axle (1) is installed on the main frame. Support axle (1) has a suspension that is fastened to the spindle at each end of the support axle. Support axle (1) provides the correct alignment and the correct location for the suspensions.The suspension consists of the following components:
Rear major bogie arm (2)
Front major bogie arm (3)
Front minor bogie arms (4)
Rear minor bogie arms (5)
Air spring (6)
Midrollers (7) The major bogie arms pivot on the spindles for the support axle. The minor bogie arms pivot on the ends of the major bogie arm. Each minor bogie arm has two axles and each axle has a pair of midrollers.Note: The midrollers are made of steel with a 12.7 mm (0.50 inch) rubber bonded to the surface.Rear major bogie arm (2) and front major bogie arm (3) have bearings and bushings that are sealed and lubricated. Rear major bogie arm (2) and front major bogie arm (3) are located at support axle (1). Front minor bogie (4) and rear minor bogie (5) are cartridge pin assemblies.Air spring (6) is installed between the major bogie arms. The air spring is used to reduce the shock on the suspension from impact loads. The air spring also equalizes the loads between the major bogies.The amount of machine weight that is carried by the suspension can be adjusted by changing the amount of air that is in the air spring.The suspension will carry more than 60 percent of the weight of a standard machine, when the air pressure that is in the air spring is approximately 448 kPa (65 psi).The following table lists the inflation pressures for the air spring.
Table 1
Pressure for Air Spring    
Operating Weight    Inflation Pressure    
14075 kg (31000 lb)    
448 34 kPa (65 5 psi)    
15450 kg (34000 lb)    
517 34 kPa (75 5 psi)    
17025 kg (37500 lb)    
552 34 kPa (80 5 psi)    
18600 kg (41000 lb)    
586 34 kPa (85 5 psi)    Note: If you increase the pressure of the air spring, the percentage of the total machine weight that is carried by the midrollers will increase.Increasing the air spring pressure can give the following benefits:
Provide better steering performance, especially when the machine is under load.
Provide an improved ride. The midrollers absorb a greater amount of the shock loads.An air spring with insufficient pressure causes poor turning performance under load and increased roughness of the ride.The best spring pressure may vary from 410 to 620 kPa (60 to 90 psi). This pressure depends on the type of equipment, soil conditions, and the required performance requirements.Various pressures should be tried to find the best setting for the particular situation. Do not exceed 650 kPa (95 psi) regardless of the