jcb JS300 Service Manual page 742

Key
A Negative Control Valve Ps1
B Restrictor Orifice
C Negative Control Valve Ps2
D Shuttle Valve
E Load Hold Check Valves (x6)
E1 Dipper 2, E2 Boom 1, E3 travel Restrictor, E4 Dipper 1, E5 Boom 2, E6 Option
F Priority Valve
F1 Boom over Bucket, F2 Boom over Swing, F3 Option/Tab Option
G Blank
H Pressure Switch
H2 Travel, H3 Excavator
I Main Relief Valve (MRV)
K Auxiliary Relief Valves (ARV)(x8)
K1 Dipper out, K2 Option, K3 Boom Up, K4 Bucket Open, K5 Boom Down, K6 Bucket Close, K7 Dipper In,
K8 Option (K2 and K8 will be blank if no option is fitted)
L Load Holding Valve (x2)
L1 Dipper, L2 Boom
M Regeneration Valve - Dipper
N Spool (x 10)
N1 Dipper 1, N2 Boom 2, N3 Swing, N4 Option, N5 Travel Left, N6 Dipper 2, N7 Boom 1, N8 Bucket, N9 Travel
Left, N10 Linear Travel (LT3)
O Shuttle Valve
P P1- Pump 2 pressure in, P2 - Pump 1pressure in
Q1, Q2 Blank
S End Caps
V V1 Merge Out, V2 Merge In
W MRV Shuttle Valve (x2)
K Fig 1. ( T K Fig 2. ( T
E-82),
E-81
K Fig 3. ( T E-84)
E-83),
9813/5100-1
Section E - Hydraulics
Hydraulic Control Valve
Layout
E-81