Fault finding
61/68
Hägglunds VI, RE 15310-WA/10.2015, Intallation and maintenance manual,
Bosch Rexroth Mellansel AB
Hydraulic motor with 2-speed valve V46-C
Fault
Probable cause
Action
The motor only works
at one speed
2-speed plug not fitted
Fit 2-speed plug in the bottom of connection ”A” in the motor.
2-speed valve of two position
type fitted – pilot pressure
too low.
Suitable pilot pressure – see 3.2.5 for valve V46-C.
The valve piston has stuck in
single-speed position due to
impurities in the oil.
Dismount piston and remove impurities.
Motor cannot be run
in single or double
speed (2-speed valve
or three position type)
Pilot pressure too low.
Required pilot pressure: See 3.2.5 for valve V46-C
The valve piston has stuck in
0-position due to impurities.
Dismount the piston and remove impurities.
Hydraulic motor with counterbalance valve V46-O
Fault
Probable cause
Action
The motor only rotates
in one direction
The valve piston has stuck
in unloaded position.
Dismount the piston and remove any impurities.
The motor does not
supply any back pressure.
The valve piston has stuck
in fully open position.
Dismount the piston and remove any impurities.
Hydraulic motor with band brake
Fault
Probable cause
Action
Insufficient braking
torque
The brake is poorly adjusted.
Adjust the brake. See the instruction for brake adjustment under 3.1.5
”Motor – front bracket”.
The brake cylinder is not
drained in the described
manner, excessive counter
pressure in drainage line.
Remove the cause of the pressure. Concerning the maximum counter
pressure, see the section dealing with draining the brake cylinder under
3.1.5 ”Motor – front bracket”.
The brake band and the brake
surface are dirty or greasy.
Dismantle the brake band and sandpaper the surface of the lining.
Clean the brake surface on the motor, If necessary, replace the
complete brake band.
The motor runs
sluggishly when idling
The brake is excessively
tensioned. The brake band
is applied despite the brake
opening.
Relieve the tension. See section dealing with draining the brake cylinder
under 3.1.5 ”Motor – front bracket”.
The brake does not open
Insufficient brake opening
pressure.
For the required opening pressure, see section dealing with draining
the brake cylinder under 3.1.5 ”Motor – front bracket”.
The brake cylinder
leaks oil
Seals or piston damage.
Replace the seals / replace the pistons.
IMPORTANT / CAUTION!
The spring in the brake cylinder is tensioned.