PUMP GP-PISTON 4Z6298 - Caterpillar

Personal injury or death can result from sudden movement of the lift or tilt cylinders.Sudden movement up or down, can cause the clearance above your head to change rapidly.Do not stand under the lift arms when testing and adjusting the lift cylinders.Do not stand under the bucket when testing or adjusting the tilt cylinder.
Start the engine and run the engine at high idle. Move the lift arms repeatedly in order to warm the hydraulic oil. The hydraulic oil (SAE 10) must be at a temperature of 65 3°C (150 5°F) in order to obtain accurate results.Note: Perform all speed tests with the engine at high idle and with an empty bucket. If the machine is equipped with the optional ride control system, place the ride control switch in the OFF position.The speeds in the following table are for a machine with a general purpose bucket.
Table 1
Speed Tests for Lift Circuit    
Function     Distance     Speed    
RAISE     Ground to fully raised position     6.8 seconds    Note: When you perform the speed tests for the tilt circuit, the bucket must be raised to the maximum height.
Table 2
Speed Tests for Tilt Circuit    
Function     Distance     Speed    
DUMP     Full Tilt Back position to full Dump position     2.9 seconds    If the travel times are not correct, check the following conditions:
Check the engine high idle rpm.
Check the pressure settings of the main relief valve and the line relief valves.
Check the implement pump flow.Reference: For information on the hydraulic pump flow test, refer to System Operations, Testing and Adjusting, "Pump Flow - Test" for the machine that is being serviced.
Check the makeup valves in the main control valve.
Check the valve spools in the main control valve.
Check the piston seals in the cylinders.