SWITCH AS-POSITION 1947839 - Caterpillar

Illustration 2 g00610635
Valve Assembly for the Holding Arrangement (A) The Pressure Sensing Line from the Thumb Cylinder (B) Tee location for the pressure test (C) Test Port (E) 169-1006 Valve (F) 9Q-9728 Valve
Connect a tee fitting at location (A). Connect a tee fitting in the pilot line at the top of the attachment stem. Connect a tee fitting at location (B). Connect the 51710 kPa (7500 psi) pressure gauge at location (A). Connect the 10342 kPa (1500 psi) pressure gauge at locations (B) and (C). Connect a 10342 kPa (1500 psi) pressure gauge in the pilot oil line for the top of the attachment stem.
Start the engine and warm the machine to operating temperature.
Set the switch in the cab to the thumb lever mode.
Set the relief valve in the attachment circuit that controls the rod end of the thumb lever cylinder. Set the relief pressure according to the manufacturer.
Set the relief valve in the attachment circuit that controls the piston end of the thumb lever cylinder. Set the pressure 2413 kPa (350 psi) less than the recommended maximum pressure. This pressure will be increased later.
Adjust the top screw on the 174-0305 valve (F) counterclockwise. The 174-0305 valve is located near the main pumps. To avoid valve damage, do not apply excessive force to the adjustment screw. The 174-0305 valve is now closed.
Illustration 3 g00608667
Speed control valve for the thumb (1) Adjustment screw locknut (2) Speed level adjustment screw (3) Speed level adjustment screw
Adjust the speed control valve in order to obtain the proper speed for the thumb lever cylinder. This speed control valve is located by the main control valve.
Adjust the thumb open speed first.
Close the thumb lever. Use the rocker switch on the right hand joystick. Press on the right side of the rocker switch.
Push the left side of the rocker switch on the right joystick. While the switch is activated, turn the adjustment screw (2) clockwise until the thumb opens at the desired speed. Tighten the locknut (1) .
Loosen the locknut (1) on the adjustment screw (3) and turn the adjustment screw counterclockwise until resistance is felt. At this point, there is no hydraulic pressure on the main valve stem. The thumb cylinder will not close.
Push on the right side of the rocker switch on the right joystick. While the switch is activated, turn the adjustment screw (3) clockwise until the thumb closes at the desired speed. Tighten the locknut.
Turn the adjusting screw on the 169-1006 valve counterclockwise until resistance is felt.
Close the thumb and stall the circuit.
Turn the adjustment screw on the 169-1006 valve (E) clockwise until the gauge at port (C) reads 4136 kPa (600 psi).
Open the thumb.
Illustration 4 g00610771
Valve Assembly for Holding Arrangement (5) 7Y-8484 Hose Assembly (6) 4I-1637 Hose Assembly (7) Hose Connector
Refer to Illustration 4. Disconnect 7Y-8484 hose