www.WorkshopManuals.co.uk
Section E
8 - 1
Component Key: (JCB 'X' Control Pattern)
A
Inlet
Parallel Gallery
B
Load Hold Check Valves
C
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.
9803/3280
Hydraulics
Circuit Descriptions
Purchased from www.WorkshopManuals.co.uk
Excavator Valve
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.
Section E
8 - 1
Issue 1