CYLINDER GP-STICK 2898078 - Caterpillar

Illustration 4 g02539445
Front Right Side of the Tractor (5) Hydraulic tank (6) Breaker relief valve (8) Return line filterBreaker relief valve (6) is located on hydraulic tank (5). Breaker relief valve (6) opens to relieve the tank pressure.Cushion-Hitch Hydraulic System
Illustration 5 g03411320
(2) Leveling valve (3A) Accumulator (low pressure) (3B) Accumulator (high pressure (16) Load cylinder (17) Bracket assembly (18) Link assembly (two) (19) Hitch assembly
Illustration 6 g03411323
(2) Leveling valve (20) Line to low-pressure accumulator (21) Line to high-pressure accumulator (22) Solenoid valve (cushion-hitch) (23) Line to head end of load cylinder (24) Drain line (25) Line to rod end of load cylinder (26) Supply to leveling valve (27) Leaf spring (28) Yoke assembly
Illustration 7 g03411325
(12) Cushion-hitch piston pump (29) Pressure line from the outlet of the cushion-hitch pump (30) Drain line from the cushion-hitch pump (31) Supply line to cushion-hitch pump
Illustration 8 g03411328
(32) Cushion-hitch control switchThe cushion-hitch is the connection between the tractor and the scraper. The cushion-hitch gives smooth vertical movement to the machine. Operation of the cushion-hitch is not needed in every type of machine operation. Operation of the cushion-hitch can be turned on and off in the cab with cushion-hitch control switch (32) .The hydraulic system for the cushion-hitch has a leveling valve (2), a load cylinder (16), cushion-hitch piston pump (12), and two accumulators (3A) and (3B). The cushion-hitch piston pump gets oil from the same hydraulic tank that is common to the rest of the tractor-scraper hydraulic systems. There is a filter in drain line that prevents large particles from contaminating the hydraulic oil.The cushion-hitch is made up of bracket assembly (17), two link assemblies (18), and hitch assembly (19). Bracket assembly (17) is connected to the scraper. Hitch assembly (19) is connected to the tractor. Link assemblies (18) connect bracket assembly (17) and hitch assembly (19). The rod end of load cylinder (16) is connected to bracket assembly (17). The head end is connected to hitch assembly (19). In the LOCKDOWN position, bracket assembly (17) and hitch assembly (19) are held in contact by oil in the rod end of load cylinder (16). In the CUSHION RIDE position, oil in the head end of the load cylinder lifts bracket assembly (17) .Cushion-hitch control switch (32) is the on/off control for CUSHION RIDE. When the machine is in operation and switch (32) is on, the oil from cushion-hitch piston pump (12) fills in the area below the pistons accumulators (3A) and (3B). The oil also goes to the head end of load cylinder (16). As the oil enters the cylinder, the rod is extended. The front of the scraper is now supported by a cushion of oil.Yoke assembly (28) connects leveling valve (2) to leaf spring (27). The leaf spring is connected to the lower link assembly (18). When bracket assembly (17) gets to the correct height above hitch assembly (19), the leaf spring and the yoke assembly cause the leveling valve to stop pump flow to the head end of the load cylinder. The accumulator is