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Troubleshooting
Bosch Rexroth AB,
Installation and maintenance manual, Hägglunds DOb, RE 15327-WA/05.2017
Causes Of Trouble And Its Effect In The Hydraulic Installation
Source of trouble,
effects
Mechanical Drive
Suction line
Pump
Pressure line
Return line
Excessive noises
1. Coupling wrongly
aligned
2. Coupling loose
3. Coupling
defective
4. Loose mounting
on pump or motor
5. Other
transmission
elements loose.
6. Pump or motor
defective
7. Direction of
rotation wrong
8. Noise dampening
not incorporated
in design (rubber-
metal mountings)
Suction line
resistance excessive
because:-
1.Suction line
blocked or leaking
2.Fluid level too low
1.Pump is running
too fast
2.Maximum pump
pressure exceeded
3.Shaft seals, or
seals on suction side
are defective
4.Pump defective
5.Pressure and
return lines
connected wrongly
6.Control system
oscillating
7.Noise dampening
not incorporated in
design
n
1.Line mounts
missing or loose
2.Poor installation
3.Pipe bore too
small
4.Installation not
bled completely
1.Line mounts
missing or loose.
2. Poor installation
3.Pipe bore too
small 4.Installation
not bled
5. Filter blocked
Insufficient power
and torque at the
hydraulic motor
(pressure too low)
1.Power
transmission
defective
2.V-belt or Toothed
belt slipping
3.Motor defective
4.Key sheared at
pump or motor
5. Incorrect
parameter values
regarding electric
motor in the VFD
1.Internal leakages
due to wear
2.Unsuitable type
3.Pump defective
4.Saftey block
pressure set too
low,
or control element
defective
1.Leakages
2.Excessive
line resistance
3.Pressure filter
blocked
1.Excessive line
resistance
2.Filter blocked
Jerky motor
movements.
(variations in
pressure and/or
flow)
1.Coupling wrongly
aligned
2.Coupling loose.
3.Coupling defective
4.Loose mounting
on pump and/
or motor 5.Other
transmission
elements loose
6.Pump or motor
defective
Suction line
resistance excessive
because:-
1.Suction line
blocked or leaking
2.Fluid level too low
1.Incorrect
parameter values in
the VFD
2.Pump defective
3.The regulator
doesn’t work as
intended.
ve
1.Installation not
bled completely
1.Excessive line
resistance
2.Filter blocked.
Foaming of the
hydraulic fluid
1. Suction line leaks
2. Fluid level too
low.
1. Shaft seals on
the suction side are
defective.
14 Troubleshooting