HEAD ASSEM. 3S4762 - Caterpillar

Illustration 1 g00592732
Location of Components (1) Oil cooler (2) Lift and tilt pilot control valve (3) Third control valve (optional) (not shown) (4) Lift and tilt control valve (not shown) (5) Main relief valve (part of main valve) (6) Implement valve (not shown) (7) Hydraulic tank (8) Access cover for oil filter (9) Tilt cylinder (10) Multipurpose bucket cylinders (Attachment) (11) Lift cylinders (two) (12) Oil cooler supply valve (mounted inside tank at the rear) (13) Diverter valve (mounted on frame) (14) Equipment pump (15) Two ripper cylinders (optional)
Hydraulic oil, under pressure higher than 27500 kPa (4000 psi) can remain in the hydraulic system after the engine and pump have been stopped. Serious injury can be caused if pressure is not released before any work is done on the hydraulic system. To release any pressure, move the hydraulic control levers into all positions after the engine is OFF.When possible, the bucket must always be flat on the ground before service work is started. When the bucket is raised for tests or adjustments, be sure that the lift arms have correct support and the bucket is in the FULL DUMP position.Always move the machine to a location away from the travel of other machines. Be sure that other personnel are not near the machine when the engine is running and tests or adjustments are being made.
The hydraulic system controls the operation of the bucket and attachments (ripper and/or multipurpose bucket).The hydraulic system contains the following components:
equipment pump (14)
hydraulic tank (7)
lift and tilt control valve (4)
oil filter (8)
implement valve (6) The system also has a mechanical bucket positioner and lift kickout, lift cylinders (11), and tilt cylinder (9).
Illustration 2 g00593792
Location of Pumps (A) Right drive pump (B) Equipment pump (C) Left drive pump (D) Charge pump
Illustration 3 g00593695
Location of Hydraulic Tank and Valve Group (A) Hydraulic tank (B) Access cover for filter (C) Fill cap location (D) Pressure tap for hydraulic tank pressureThe optional hydraulic system has ripper cylinders (15) and/or multipurpose bucket cylinders (10). With one attachment, third control valve (3) is used.With two attachments, diverter valve (13) is used in addition to third control valve (3) .To control the attachments, an additional control lever is added in the operator's compartment.Other components of the system include oil cooler (1) and oil cooler supply valve (12) .The hydraulic system is a series circuit that is not completely continuous. The third control valve is first in the series circuit. The tilt circuit is second and the lift circuit is last.Return oil from the tilt circuit bypasses the lift circuit when the tilt control valve is in the TILT BACK position.All other circuits and functions are in a complete series.Lift and tilt control valve (4) has two spools. One spool is for bucket RAISE and LOWER, and one spool is for bucket TILT BACK and DUMP.The tilt valve spool has three positions. The positions are TILT BACK, HOLD, and DUMP.The detent for the TILT BACK position is located in the pilot control valve. When the