Troubleshooting - Bosch Rexroth Hagglunds DUc MS2 Installation & Maintenance Manual

80/88 Hägglunds DUc Drive unit | Troubleshooting
Source of trouble,
Mechanical Drive
effects
Excessive noises 1. Coupling
wrongly aligned
2. Coupling loose
3. Coupling
defective
4. Loose mounting
on pump and/or
motor 5. Other
transmission
elements loose.
(V- belts, Toothed
belts(etc)
6. Pump or motor
defective
7. Direction of
rotation wrong
8. Noise
dampening not
incorporated in
design (rubber-
metal mountings)
Insufficient power 1. Power
and torque at the transmission
hydraulic motor defective
(pressure too low) 2. V-belt or
Toothed belt
slipping
3. Direction of
rotation wrong
4. Motor defective
5. Key sheared at
pump or motor
Jerky motor
1. Coupling
movements. wrongly aligned
(variations in
2. Coupling loose.
pressure and/or 3. Coupling
flow)
defective
4. Loose mounting
on pump and/or
motor
5.Other
transmission
elements loose
6. Pump or motor
defective
7. Direction of
rotation wrong
Foaming of the
hydraulic fluid
Bosch Rexroth AB, Version 06.2020, RE 15326-WA

13 Troubleshooting

Causes Of Trouble And Its Effect In The Hydraulic Installation
Suction Line
Suction line
resistance
excessive because:
1. Suction valve
is closed or only
partially open
2. Suction filter
clogged or too
small (if fitted)
3. Suction line
blocked or leaking
4. Suction line has
wrong dimensions
(ie pipe bore ), or
too many bends.
5. Fluid level too
low
Suction resistance
is excessive :-
1. Valve in the
suction line is
partially open
2. Suction filter
clogged or too
small (if fitted)
3. Suction line
blocked or leaking
4. Suction line is
sized wrong
5. Fluid level too
low
1. Suction line
leaks
2. Fluid level too
low
3. Wrongly
designed reservoir.
Pump Pressure Line
1. Pump is running 1. Line mounts
too fast missing or loose
2. Maximum pump 2. Poor installation
pressure exceeded 3. Pipe bore too
3. Boost pump small
defective 4. Installation not
4. Shaft seals, or bled completely
seals on suction
side are defective
5. Pump defective
6. Pressure and
return lines
connected wrongly
7. Control system
oscillating
8. Noise
dampening not
incorporated in
design
1. Internal 1. Leakages
leakages due to 2. Excessive line
wear resistance
2. Unsuitable type 3. Pressure filter
3. Pump defective blocked
4. End-of-control
pressure set too
low, or control
element defective
1. With variable 1. Installation not
pumps, the control bled completely
system is defective
2. Pump defective
3. System
conditions react on
the pump control
system
4. Unsuitable pilot
valve
1. Shaft seals on
the suction side
are defective.
2. Case drain line
terminates above
the fluid level.
Return Line
1. Line mounts
missing or loose.
2. Poor installation
3. Pipe bore too
small
4. Installation not
bled
5. Return
terminates above
fluid level
6. Return filter
blocked
1. Excessive line
resistance
2. Filter blocked
1. Excessive line
resistance
2. Filter blocked.
1. Return line
terminates above
the fluid level.
2. Vortex effect
due to wrongly
positioned lines