jcb JS300 Service Manual page 775

Inspection
Before assembling the Directional control valve make sure
that a thorough inspection of all the components is carried
out. Remember that although a failed component may be
easy to identify, the cause may be less easy to trace. It is
also possible that a failed component may have caused
damage to other areas of the valve.
1 Carefully clean all components using a suitable de-
greasing agent.
2 Carefully inspect all components for signs of
excessive wear or damage. If wear or damage is
evident, components must be renewed.
Note: `O'-rings and other sealing materials should
preferably be replaced
disassembled but they may be re-used provided a careful
check is made that they are undamaged.
Assembly
Note: `O'-rings and other sealing materials should
preferably be replaced
disassembled but they may be re-used provided a careful
check is made that they are undamaged.
Note: When hexagonal socket (hex) bolts 29 are loosened
the seal washers 30 must be replaced.
Note: Fit all components in the same positions as before
disassembly
!M
WARNING
Always wear safety glasses when dismantling
assemblies containing components under pressure
from springs. This will protect against eye injury from
components accidentally flying out.
GEN-6-2
1 Assemble washer 28, shim 27, secondary pressure
setting spring 25 and spring washer, in that order,
onto spool 26
2 Push spool 26 through the larger hole of spring
washer 24 and assemble by sliding the spring washer
sideways while bending the secondary pressure
spring
E-114
each time the valve
each time the valve
3 Fix casing 20 in a vice. Fit return spring 21 into
casing.
4 Fit the pressure reduction valve sub-assembly,
assembled in 1 and 2 above, into casing 20. When
fitting the pressure reduction valve sub assembly,
take care not to hit the lower end of the spool against
the edge of the casing,
is
is
Note: Be careful of the casing edge A.
5 Fit `O'-rings 18, 19 into the casing.
6 Fix upper casing 10 in a vice and fit steel balls 17.
7 Fit spring washer 16 into casing 10 using tweezers
etc.
8 Fit damping spring 8 into casing 10.
9 Fit piston 14 into casing 10.
10 Fit `O'-ring 11 to plug 7.
11 Fit packing 13 to plug 7. Be careful of the direction
when fitting the packing,
light coating of grease before fitting packing.
9813/5100-1
Section E - Hydraulics
Travel Pedal Valve
Dismantling and Assembly
K Fig 4. ( T
E-114).
A
Fig 4.
K Fig 5. ( T
E-115). Apply a
A406350-1
E-114