DIAPHRAGM 6P4639 - Caterpillar

Illustration 1 g02621969
Ensure that transport pin assembly (1) and transport guard (2) are installed on the felling head.Note: Perform all speed tests with the engine at high idle.
Cycle each function completely.
Record the speed of each cycle. Refer to Table 1 and Table 2 for the cycle time that corresponds to the function that is being adjusted.
Table 1
Speed Test for Grapple Arm and Accumulator Arm    
Function     Distance     Speed    
OPEN     Stop to stop     0.7 to 0.9 seconds    
CLOSE     Stop to stop     0.8 to 1.0 seconds    
Table 2
Speed Test for Lift Function    
Function     Distance     Speed    
LIFT UP     Stop to stop     2.9 to 3.5 seconds    
LIFT DOWN     Stop to stop     1.8 to 2.2 seconds    If the travel times are not correct, check the following conditions:
Check the hydraulic pump flow.
Check the line relief/makeup valves in the control valves for the grapple arm and the accumulator arm.
Check the valve spools in the control valves.
Check the piston seals in the cylinders.