Wacker Neuson 28Z3, Service Manual

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SHB 28Z3 EN – Edition 2.0 * 28z3s312.fm
3-35
Maintenance
Pressure check of gear pump P3
Hydraulic supply for stabiliser blade, auxiliary hydraulics, boom swivel, upper carriage
rotation, optional 3rd control circuit
Checking primary pressure limiting valve 3 (PPLV 3)
☞
Connect a pressure gauge to measuring port MP 3 44/3
☞
Extend the stabiliser blade ram as far as it will go at maximum engine speed
☞
Check and make a note of the pressure value.
Checking pressure drop
☞
Extend the stabiliser blade ram as far as it will go at maximum engine speed
☞
Swiftly reduce engine speed from maximum to minimum -> pressure drop
☞
Check and make a note of the pressure value.
➥
Pressure drop should not be more than 10 % of the specified value
Setting primary pressure limiting valve 3 (PPLV 3)
☞
Adjust the pressure at the primary pressure limiting valve (PPLV 3) 45/C on the main
valve block
☞
Slacken the locknut of the pressure limiting valve
☞
Unscrew the pressure limiting valve until you can read off a pressure drop on the
pressure gauge
➥
The valve seat may be stuck and must be slackened first
☞
Adjust the pressure limiting valve and tighten the locknut
☞
Check the primary pressure limiting valve 3 and the pressure drop once adjustment is
over
Also check with the retract stabiliser blade, boom swivel and upper carriage rota-
tion functions
Checking the auxiliary hydraulics pressure
Notice!
Factory indications for auxiliary hydraulics secondary valves are possibly invalid –
adapt these values to the attachment!
3
Fig. 44: Measuring port P3
Fig. 45: Primary pressure limiting valve 3
C