HOSE 5302787 - Caterpillar

Illustration 1 g02139324
Final Drive Cross Section (1) Brake piston (2) Brake piston chamber (3) Disks and plates (4) Brake passage (5) Brake springs (6) Brake couplingThe parking brakes are spring applied and hydraulically released. These wet brakes are engaged through the compression of a series of disks and plates (3). The disks are splined to brake coupling (6). The plates are splined to the housing. The brake plates and disks are splash lubricated. Oil from the auxiliary hydraulic pump is used in order to release the parking brakes.When the brakes are engaged, the brake solenoid opens brake passage (4) to the hydraulic tank. Brake springs (5) move the brake piston against brake disks and plates (3). This action compresses the disks and plates, so brake coupling cannot rotate (6) .When the brakes are released, auxiliary pressure is directed into brake piston chamber (2). Auxiliary pressure acts against brake piston (1). This action is in opposition to brake springs (5). The auxiliary pressure overcomes the spring force, and the brake piston moves. This movement releases the compressive force on the disks and on plates (3).