Service Manual and
Axial Piston Motors Series 20
Repair Instructions
L1003443
• Rev BA • Jun 2014
13
System Operating Hot
System will not Operate in
either Direction
Troubleshooting
Check fluid
level in
reservoir
Fill to
proper level
Inspect heat
exchanger
Inspect
inlet filter
Repair
or replace
OK
to Low
Defective
OK
OK
Replace
Replace
transmission
(pump + motor)
Clogged
Inspect motor
by-pass valve
(if used)
OK
OK
Repair
or replace
Defective
Check system
pressure
(see
page 13
)
Reduce
machine load
Defective
Check fluid
level in
reservoir
Check control
linkage
Inspect motor
by-pass valve
(if used)
Repair
or replace
OK
Defective
OK
Fill to
propper level
to Low
Repair
or replace
Defective
Check charge
pressure
(see
Series20 Axial Piston
Pumps, Service Manual
and Repair Instruction
)
OK
Inspect
charge pump
(see
Series20 Axial Piston
Pumps, Service Manual
and Repair Instruction
)
Inspect
inlet filter
Repair or replace
(see
Series20 Axial Piston
Pumps, Service Manual
and Repair Instruction
)
Defective
Replace
Defective
Inspect charge
pressure relief valve
(see
Series20 Axial Piston
Pumps, Service Manual
and Repair Instruction
)
Repair or replace
(see
Series20 Axial Piston
Pumps, Service Manual
and Repair Instruction
)
Clogged
Inspect purge
relief valve
at motor
(see
page 21
)
Repair or
replace the
valve block
(see
page 19
)
Defective
Replace
transmission
(pump + motor)
Inspect
control valve
(see
Series20 Axial Piston
Pumps, Service Manual
and Repair Instruction
)
Replace
control valve
(see
Series20 Axial Piston
Pumps, Service Manual
and Repair Instruction
)
Defective
Inspect motor
by-pass valve
(if used)
Repair
or replace
Defective
Check system
pressure
(see
page 13
)
to low in
neutral and
forward or
reverse
to low in
forward or
reverse
to low in
neutral
OK
OK
OK
OK
OK
OK
OK
