Dismantling and Assembly
Precision Control (Servo)
(Machines from January 2003)
Dismantling
The excavator valve block is a ‘sandwich type’, which is
made up of a number of separate sections. The illustration
shown on the opposite page is intended as a guide to
dismantling. Be sure to note the location of all components
when dismantling. Although some components may appear
to be identical they are not interchangeable. Make sure that
components are assembled in their original positions.
1
Remove the excavator valve block from the machine.
2
Remove the three tie rod nuts
1
.
3
Carefully separate and remove the outlet section
2
followed by the remaining service sections
3
. If the inlet
section
4
is to be replaced, remove and retain the tie
rods
5
.
Assembly
Assembly is the reverse of the dismantling sequence.
1
Clean the valve components in an appropriate solvent.
Ensure that the mating faces of the valve sections are
thoroughly clean before assembly.
2
Renew the ‘O’ rings located between the valve sections.
Make sure the ‘O’ ring seals are not trapped or
damaged.
3
Lubricate parts with JCB Hydraulic Fluid before
assembling. Make sure that all the parts move freely.
Torque Settings
Item
Nm
kgf m
lbf ft
1
35 3.6 25.8
6A
10
1
7.4
7
20
2
14.8
8
45
4.6
33.2
9
100
10.2
73.8
10
70
7.1
51.6
11
70
7.1
51.6
11A
70
7.1
51.6
12
60
6.1
44.3
13
30
3
22.1
14
20
2
14.8
14A
45
4.6
33.2
Service Spools
Each of the service spools
6
can be removed as shown.
Care must be taken to ensure that the spool is not damaged
when removing it from the block. Note that all spools are
similar in appearance but must not be interchanged as they
are matched to their bores. All spools have the same
centring and sealing components.
Flow Regulator Valve
The dismantling and assembly procedures for the flow
regulator valve
7
are detailed separately, refer to
Flow
Regulator Valve
.
Load Sense Relief Valve
The dismantling and assembly procedures for the load
sense relief valve
8
are detailed separately, refer to
Load
Sense Relief Valve
.
Flushing Valve
The flushing valve
9
can be removed as shown.
Auxiliary Relief Valves
The A.R.V's
10
appear identical but have various pressure
settings, refer to
Technical Data
. Ensure that they are
correctly adjusted and fitted in their specified positions.
The dismantling and assembly procedures for the ARV’s are
detailed separately, refer to
Auxiliary Relief Valves (ARV’s)
.
Anti-cavitation Valve
The dismantling and assembly procedures for the
anticavitation valve
11
are detailed separately, refer to
Anti-
cavitation Valve
.
Pressure Compensator Valves
Each of the pressure compensator valves
12
can be
removed as shown. Note that all valves are identical in
appearance. Note that components are not interchangeable.
Load Hold Check Valves
Each of the load hold check valves
13
can be removed as
shown. Note that all valves are identical in appearance.
Ensure good condition of seating faces on poppets and on
the mating faces in the valve block.
Hydra-clamp Solenoid Valve
The hydra-clamp solenoid valve
14
can be removed as
shown.
62 - 21
Section E
9803/3280
Section E
62 - 21
Issue 1
Excavator Valve