jcb 1CX, Service Manual

Page: 183 / 242

19 - 2
Pressure Reducing Solenoid Valve
up to serial no. 752462
Removal
! !
WARNING
Hydraulic Pressure
Hydraulic fluid at system pressure can injure you. Before
disconnecting or connecting hydraulic hoses or
couplings, vent the pressure trapped in the hoses in
accordance with the instructions given in this
publication.
HYD-1-5
Before working on the hydraulic system ensure that the
engine is switched off and the starter key removed.
Vent the hydraulic pressure (see page E/2 - 1).
Remove and plug all hydraulic hoses. Plug exposed
connections in the valve body 1. Disconnect the solenoid
electrical cables.
Remove bolts X (2 off) and remove the valve.
Replacement
Replace bolts X and torque tighten to 12 Nm (9 lbf ft, 1.2 kgf
m).
Reconnect the solenoid valves and all hydraulic
connections.
Dismantling
Secure the valve body 1 into a suitable soft jaw vice or
fixture. Remove the pressure reducing cartridge valve 2 and
the solenoid cartridge valve 3. Solenoids A and B can be
removed if necessary by unscrewing the coil retaining nut 4.
All seals and 'O' rings should be discarded. Do not
dismantle the cartridges.
If damage or excessive wear is found a cartridge should be
replaced as a complete unit.
The machined orifice 5 should be examined for wear but not
removed unless being renewed. Examine wiring for damage
or chafing; replace as necessary.
Assembly
Assembly is a reversal of the dismantling procedure. Fit new
'O' ring seals. Torque tighten to 23-28 Nm (17 - 21 lbf ft, 2.3
- 2.9 kgf m).
Check (and if necessary adjust) the setting of cartridge valve
2 (see below).
Replace solenoids on cartridge 3, torque tighten the coil
retaining nut 4 to 5 - 7 Nm (3.7 - 5.2 lbf ft, 0.5 - 0.7 kgf m).
Adjusting the Pressure Reducing Valve Cartridge
This cartridge should not be dismantled. If it malfunctions it
should be replaced by a new one.
Before checking the setting make sure the hydraulic oil is at
it’s correct working temperature.
To check the setting, connect a pressure gauge to the test
point as follows:
a On machines up to serial no. 751715 the test point is
located under the throttle pedal plate as shown at E.
b From serial no 751716 the test point is located at the
rear of the left hand side of the engine as shown at F.
Ensure that the seat is facing forward then start the engine
and run at maximum speed. Operate the arms lower service
until the rams are fully closed to ‘blow off’ the M.R.V. Check
the gauge reading which should show the regulated
pressure.
See Technical Data for correct setting.
If the setting is incorrect, stop the engine. Remove the
cartridge dust cover C and adjust screw D to achieve the
required pressure. Replace dust cover C before restarting
the engine to recheck the pressure otherwise oil will leak
from the valve.
Section E Hydraulics
9803/8550
Section E
19 - 2
Issue 4*
Valves
205001
*
*
www.WorkshopManuals.co.uk
Purchased from www.WorkshopManuals.co.uk