62 - 2
Dismantling and Assembly
Auxiliary Relief Valve (ARV)
Seven A.R.V's are fitted to the excavator valve block. The
following procedure covers the dismantling and assembly of
A.R.V's 4L, 4M and 4P. A.R.V's 4H, 4J, 4K and 4N are
identical in design to those fitted in the loader valve, refer to
Loader Valve - Dismantling and Assembly. The A.R.V's
have various pressure settings, refer to Technical Data.
The numerical sequence shown on the illustration is
intended as a guide to dismantling.
For assembly the sequence should be reversed.
Great care should be taken when dismantling and
assembling a valve to avoid the following:-
Contamination
Damage to spools
Damage to seal grooves
Any of the above may result in possible problems with the
operation of the valve.
Dismantling
When removing 'O' Rings and seals, use an appropriatly
rounded tool that WILL NOT cause any damage to the seal
grooves.
Discard ALL 'O' Rings. DO NOT use worn or damaged
items.
Retain shims 7 for re-assembly.
Note: The arrangement of A.R.V.'s shown opposite is that
used with the JCB 'X' control pattern.
For ISO '+' control pattern 4K and 4M swap positions, 4L
and 4N swap positions.
Inspection
Inspect the valve components for scratches, nicks or any
other type of damage, replace with new if required.
Assembly
Renew all seals, using JCB Hydraulic Fluid as a lubricant.
Fit shims 7 to the same total thickness as those removed.
Note: The shims are only intended to limit the maximum
pressure setting to which it is possible to adjust the valve.
The specified pressure setting of each valve is achieved by
adjusting screw 5 (see Service Procedures, Pressure
Testing - ARV’s). If the specified pressure cannot be
achieved under test, it is permissible to add further shims as
required.
Torque Settings
Item Nm kgf m lbf ft
1 21.3 - 26.7 2.22 - 2.78 16 - 20
3 21.3 - 26.7 2.22 - 2.78 16 - 20
6 41 - 68 4.15 - 6.9 30 - 50
Section E Hydraulics
9803/7130
Section E
62 - 2
Issue 1
Excavator Valve
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