jcb JS200 Service Manual page 225

Section E
4 - 6
Port Relief Pressure
Note: Because port relief pressure is set higher than main
relief pressure, it is necessary to temporarily set the main
relief pressure higher than port pressure.
Temporary setting of main relief pressure
1. Prepare the machine
a. Put the operators lever into neutral, lower the gate
lock lever. Start the engine and place the machine on
level ground, lower and open the dipper and set the
bucket on the ground.
b. Run the engine at maximum no-load speed and in
the S mode.
2. Loosen the lock nut A and tighten the pressure raising
adjusting screw B 180° clockwise, then tighten the lock
nut A of the Main Relief Valve.
3. After completing an adjustment on a particular port relief
valve, loosen the lock nut A and unscrew the pressure
raising adjusting screw B, over 180° to return to the
standard setting pressure.
4. Stop the engine
9803/6400
Hydraulics
Pressure Testing
B
A
Section E
4 - 6
Issue 1