Adjusting Swivel Relief Valve Pressure; Adjust The Ls Control Differential Pressure Adjusting Spring Force - Kubota KX080-4 Workshop Manual

KX080-4, WSM

(6) Adjusting Swivel Relief Valve Pressure

IMPORTANT
• When checking the relief pressure of the swivel motor on the machine, measure the main relief pressure
and if the main relief pressure is within factory specifications, the swivel relief valve is considered to be
normal.
• If there is a problem, we recommend replacing the swivel relief valve as an assembly.

(7) Adjust the LS Control Differential Pressure Adjusting Spring Force

CAUTION
• Perform this adjustment procedure only when the LS regulator has been disassembled or when
readjustment is necessary.
• Increasing the speed above the factory specification may damage the machine so never raise the speed
above the factory specification.
• If it is out of adjustment, matching for the entire machine will be off and the operating speed of each
device, including the boom, arm, etc. will be altered.
Change/turn for the swivel relief valve (reference values)
1/4
2.3 MPa
Amount adjuster
23.0 kgf/cm
screw turned
326 psi
(1) Swivel Right Relief Valve (cSR)
[Measurement]
1. Measure the speed of the swing according the section
Measuring Hydraulic Cylinder Operating Time.
2. If a value within factory specifications is not obtained, loosen the
LS regulator lock nut.
3. Turn the adjuster screw with a hex wrench to adjust the spring
tension.
After setting the pressure, always check the swing speed
according to the section Measuring Hydraulic Cylinder
Operating Time.
4. Tighten the lock nut.
5. Measure each operating time and make sure they are within
specifications.
(1) 1.0 m (40 in.)
(2) Lock Nut
(3) Adjuster Screw
3-S147
HYDRAULIC SYSTEM
RY9212148HYS0338US0
1/2 3/4
4.5 MPa 6.8 MPa
2 2
45.9 kgf/cm 68.9 kgf/cm
653 psi 979 psi
(2) Swivel Left Relief Valve (cSL)
RY9212148HYS0339US0
(a) Increase Speed
(b) Reduce Speed
RY9212148HYS0340US0
KiSC issued 08, 2015 A
1
9.0 MPa
2 2
91.8 kgf/cm
1305 psi