jcb JS300 Service Manual page 932

Checking Swing Bearing Vertical Lift
Fig 21.
1 First set the Dipper in a perpendicular position and
position the bucket 200 mm (9 in) above the ground,
stop the engine.
Fig 22.
2 Install a dial gauge and set the needle to the Zero
Point
E-271
Hydraulic System Fault Finding
3 Start the engine and lift the main body with the bucket,
when the bottom of the shoe is 100 mm (4 in) above
the ground, note the reading on the dial gauge. The
needle will turn in the counter clockwise direction.
This value becomes L1, lower the body to the ground
and confirm the needle reads zero.
4 Then rotate the main body 180° and repeat the
procedure, this time the needle will rotate clockwise.
This value becomes L3.
9813/5100-1
Section E - Hydraulics
Test 017: Testing Swing Bearing
Fig 23.
Fig 24.
E-271