Operation and maintenance manual

Section 230-0040
Body System - Hydraulic Tank
SM 1913 Rev 2 10-03
2
SM - 1847
OPERATION
Numbers in parentheses refer to Fig. 1, unless
otherwise specified. Refer to Fig. 2 for hydraulic
schematic of hydraulic tank.
Oil from hydraulic tank (1) is filtered through strainer
(12) before it is pumped through the respective
hydraulic systems.
The brake control oil is drawn from hydraulic tank (1)
by brake pump (4, Fig. 2) and pumped to the brake
manifold valve to supply the braking system. Refer to
Section 250-0050, BRAKE MANIFOLD VALVE.
The steering and body hoist oil is drawn from hydraulic
tank (1) by main hydraulic pump (2, Fig. 2) and
pumped to the flow amplifier valve to supply the
steering and body hoist systems. Refer to Section
220-0100, FLOW AMPLIFIER VALVE.
Emergency steering oil is drawn from hydraulic tank
(1) by emergency pump (3, Fig. 2) and is pumped to
the emergency valve. Should a failure occur at the
main hydraulic pump the emergency pump will supply
the steering system with oil to enable the vehicle to be
brought to a safe halt.
Return oil from the hydraulic systems flows through
hydraulic oil cooler (5, Fig. 2) and filter assembly
(13 & 32) before entering the tank storage area. The
filter assembly has a bypass valve which allows oil to
bypass element (32) when it is cold or when the filter
element is plugged. The bypass valve starts to open
at a pressure differential of 1.5 bar (22 lbf/in
2
) and is
fully open at 3.5 bar (50 lbf/in
2
). Visual indicator (29)
shows red when element (32) requires to be changed.
MAINTENANCE
Numbers in parentheses refer to Fig. 1.
Note: Tighten all fasteners without special torques
specified to standard torques listed in Section
300-0080, STANDARD BOLT AND NUT TORQUE
SPECIFICATIONS.
Fig. 2 - Hydraulic Schematic of Hydraulic Tank
1 - Hydraulic Tank
2 - Main Hydraulic Pump
3 - Emergency Pump 4 - Brake Pump 5 - Hydraulic Oil Cooler
SUPPLY TO
BRAKE MANIFOLD
VALVE
SUPPLY TO
EMERGENCY
VALVE
RETURN
TO TANK
SUPPLY TO FLOW
AMPLIFIER VALVE
1
5
3
2
4