Danfoss 20 Series - Troubleshooting; System Response Is Sluggish

Service Manual and
Axial Piston Pumps Series 20
Repair Instructions
L1003506 • Rev BA • Jun 201412
Check control
linkage
Repair
or replace
Inspect high pressure
relief valve
(see Series 20 Axial Piston
Motors, Service Manual
and Repair Instruction)
Insert charge
check valves
(see page 14)
Repair
or replace
(see page 21,22)
Inspect shuttle valve
in valve block
(see Series 20 Axial Piston
Motors, Service Manual
and Repair Instruction)
Repair or replace
the valve block
(see Series 20 Axial Piston
Motors, Service Manual
and Repair Instruction)
OK
DefectiveDefective
OK OK
Inspect control valve
(see page 15)
Replace control valve
(see page 23)
Defective
Defective Defective
OK
Repair or replace
(see Series 20 Axial Piston
Motors, Service Manual
and Repair Instruction)
Check charge
pressure
(see page 14)
Inspect
control valve
(see page 15)
Inspect motor
by-pass valve
(if used)
Replace
control valve
(see page 23)
OK
Defective
OK
OK
Repair
or replace
Defective
Replace
transmission
(pump + motor)
OK
Inspect charge
pressure
relief valve
(see page 14)
Repair
or replace
(see page 21, 22)
Inspect purge
relief valve at motor
(see Series 20 Axial Piston
Motors, Service Manual
and Repair Instruction)
Inspect charge
pressure
relief valve
(see page 14)
Repair or replace
the valve block
(see Series 20 Axial Piston
Motors, Service Manual
and Repair Instruction)
DefectiveDefective
Repair
or replace
(see page 21, 22)
Defective
Inspect
inlet filter
OK OK
Replace
Clogged
Inspect
charge pump
(see page 14)
Repair
or replace
(see page 21, 22)
Defective
to low
in
neutral
to low in neutral and
forward or reverse
to low inforward
or reverse
System response is sluggish
Transmission Operates in
one Direction Only
Troubleshooting