Operation and maintenance manual

Section 230-0121
SM 1448 Rev 1 1-02
1
BODY SYSTEM - Pilot Supply Valve
Fig. 1 - Exploded View of Pilot Valve
1 - Valve Body
2 - Spring Cover
3 - 'O' Ring
4 - Control Spring
5 - Spring Guide
6 - Control Spool
SM - 1870
DESCRIPTION
The pilot supply valve can be identified as item 5 in the
layout drawing in Section 230-0000, BODY SYSTEM
SCHEMATIC.
Mounted off the cradle assembly at the rear of the cab,
the pilot supply valve is located in the hydraulic servo
control lines. See Fig. 2 for schematic symbol.
The pilot supply valve is a direct acting pressure
reducing valve which steps down the supply pressure
of 185 bar (2 682 lbf/in²) to 30 bar (435 lbf/in²). Intregal
of the pilot supply valve is a relief valve which opens at
45 bar (652 lbf/in²).
7- Plug
8 - 'O' Ring
9 - Seat
10 - 'O' Ring
11 - Spacer
12 - Pilot
13 - Spring
14 - 'O' Ring
15 - Plug
16 - Plug
17 - 'O' Ring
18 - Adaptor
19 - Plug
20 - Plug
21 - 'O' Ring
22 - Reducer
23 - Adaptor
Fig. 2 - Pilot Supply Valve Schematic Symbol
SM - 1871
24 - Elbow
25 - Tee Piece
26 - Elbow
27 - Bolt
28 - Lockwasher
2
3
4
5
6
15
14
13
12
1
16
17
18
19
1919
11
10
9
8
7
23
26
24
25
23
23
24
21
22
20
28
27
19
CRADLE
ASSEMBLY
TO BRAKING
SYSTEM
TO BODY
CONTROL
VALVE
TO BODY
CONTROL
VALVE
FROM BRAKING
SYSTEM
P2P1
T2T1
U1 U2
45 bar (652 lbf/in²)
30 bar (435 lbf/in²)