jcb JS200 Service Manual page 226

Section E
4 - 7
Port Relief for Boom Ram
1. Prepare the machine
a. Put the operator lever into neutral, lower the gate lock
lever. Start the engine and place the machine on
level ground, lower and open the arm and set the
bucket on the ground.
b. Stop the engine, and release hydraulic pressure.
(See Releasing Tank Pressure).
c. Connect a 0-500 bar (0-7000 lb/in
and adaptor to port P2 on the hydraulic pump.
2. Refer to the previous section "Temporary setting of main
relief pressure" and complete step 2.
3. Pressure Adjustment
a. Start the engine and lower the gate lock lever, run
the engine at maximum no-load speed and in the
S mode.
b. Position the boom lever in the raised position and
maintain.
c. Check the gauge for the set pressure of 377 bar ±
14.4 bar (5546 ± 213 lb/in
adjust the port relief valve A by loosening the lock nut
B and always coming up to the correct set pressure
by first unscrewing, and then screwing in adjusting
screw C.
4. Adjust the boom lowering port relief valve D, as above,
to the set pressure of 241 ± 14.4 bar (3555 ± 213 lb/in
by first positioning the boom lever in the lowered position
and maintaining it.
5. If the boom cannot be lowered fully, the two ARV's can
be exchanged so that the ARV of the boom lowering can
be adjusted in the boom raising position (boom lever in
raised position) and then replaced.
6. Adjust the main relief Pressure
See previous section "Temporary setting of main relief
pressure", item 3.
7. Stop the engine and release the hydraulic pressure, (see
Releasing Tank Pressure), remove the pressure gauge
and adaptor.
9803/6400
Hydraulics
Pressure Testing
) pressure gauge
2
). If it is outside the limits,
2
2
D
)
Section E
4 - 7
A
C
B
Issue 1