9803/3280
Issue 1
8 - 1
8 - 1
Circuit Descriptions
Section E
Section E
Excavator Valve
Component Key: (JCB 'X' Control Pattern)
A
Inlet
B
Parallel Gallery
C
Load Hold Check Valves
4A
Slew Spool
4B
Boom Spool
4C
Stabiliser Spool
4D
Stabiliser Spool
4E
Dipper Spool
4F
Bucket Spool
Note:
Machines with ISO control pattern have the boom and
dipper spools interchanged.
Manual Control - Neutral Circuit
Oil from the loader valve enters the excavator valve at
A
and flows through the neutral gallery and around the waists
of the solid spools. It also fills the parallel gallery
B
but is not
at a high enough pressure to open the load hold check
valves
C
.