Danfoss 45 K2 Series Setup guide

Repair Instructions
Axial Piston Open Circuit Pumps
Series 45 K2
powersolutions.danfoss.com

Revision history Table of revisions
Date Changed Rev
April 2017 First edition 0101
Repair Instructions
Series 45 Frame K2 Axial Piston Pumps
2 | ©Danfoss | April 2017 AX00000305en-US0101

Introduction Overview..............................................................................................................................................................................................4
General instructions........................................................................................................................................................................ 4
Safety Precautions............................................................................................................................................................................5
Symbols used in Danfoss literature............................................................................................................................................6
Disassembly Auxiliary pad.......................................................................................................................................................................................7
Remove control.................................................................................................................................................................................8
Displacement limiter.......................................................................................................................................................................8
Servo piston........................................................................................................................................................................................9
Disassembly.................................................................................................................................................................................. 9
Endcap and valve plate.................................................................................................................................................................. 9
Cylinder kit........................................................................................................................................................................................10
Input shaft and swashplate........................................................................................................................................................11
Shaft seal...........................................................................................................................................................................................12
Control............................................................................................................................................................................................... 13
Cylinder block Kit disassembly..................................................................................................................................................17
Inspection Pistons and slippers.......................................................................................................................................................................19
Ball Guide, Slipper retainer, and Hold-Down Pins..............................................................................................................19
Block spring, and washers...........................................................................................................................................................19
Cylinder block..................................................................................................................................................................................20
Control............................................................................................................................................................................................... 20
Fan Drive Control...........................................................................................................................................................................22
Shaft ...................................................................................................................................................................................................23
Journal Bearing...............................................................................................................................................................................23
Valve Plate........................................................................................................................................................................................ 24
Housing............................................................................................................................................................................................. 24
Shaft bearing kits........................................................................................................................................................................... 24
Servo piston..................................................................................................................................................................................... 25
Endcap............................................................................................................................................................................................... 25
Swashplate....................................................................................................................................................................................... 25
Displacement Limiter................................................................................................................................................................... 26
Displacement Limiter..............................................................................................................................................................26
Auxiliary Pad.................................................................................................................................................................................... 26
Reassembly Journal bearing...............................................................................................................................................................................27
Bias Spring, swashplate, and Bearing..................................................................................................................................... 27
Input shaft.........................................................................................................................................................................................28
Cylinder kit assembly....................................................................................................................................................................28
Cylinder kit installation................................................................................................................................................................ 29
Valve plate and Endcap............................................................................................................................................................... 29
Shaft seal...........................................................................................................................................................................................30
PC control..........................................................................................................................................................................................31
LS control (optional)......................................................................................................................................................................31
Fan Drive Control...........................................................................................................................................................................33
Install the control...........................................................................................................................................................................34
Install auxiliary mounting pad...................................................................................................................................................34
Install servo piston.........................................................................................................................................................................35
Install displacement limiter........................................................................................................................................................36
Displacement Limiter..............................................................................................................................................................36
Repair Instructions
Series 45 Frame K2 Axial Piston Pumps
Contents
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Overview
This manual details the major repair procedures for Series 45 Frame K2 open circuit axial piston pumps.
These include the complete disassembly, inspection, and reassembly of the unit. Where rework of worn
or damaged components is possible, specifications are given to ensure these parts meet factory
tolerances. Only Danfoss Authorized Service Centers (ASCs) are authorized to perform major repairs.
Danfoss ASCs are trained by the factory to perform major repairs and their facilities are certified on a
regular basis.
W
Warning
Use of components that do not comply with rework specifications may result in loss of performance,
which may constitute a safety hazard. Do not reuse components that don’t comply to given
specifications: replace with genuine Danfoss service parts.
Minor repair procedures, adjustments, and troubleshooting information are given in the Series 45 Frame
K2 Open Circuit Axial Piston Pumps Service Manual, AX00000304. Minor repairs include service
operations that can be performed without removing the unit’s endcap. Removal of the endcap voids your
warranty.
General instructions
Follow these general procedures when repairing Series 45 variable displacement open circuit pumps.
Remove the unit
Prior to performing major repairs, remove the unit from the vehicle/machine. Chock the wheels on the
vehicle or lock the mechanism to inhibit movement. Be aware that hydraulic fluid may be under high
pressure and / or hot. Inspect the outside of the pump and fittings for damage. Cap hoses after removal
to prevent contamination.
Keep it clean
Cleanliness is a primary means of assuring satisfactory pump life, on either new or repaired units. Clean
the outside of the pump thoroughly before disassembly. Take care to avoid contamination of the system
ports. Cleaning parts by using a clean solvent wash and air drying is usually adequate.
As with any precision equipment, all parts must be kept free of foreign materials and chemicals. Protect
all exposed sealing surfaces and open cavities from damage and foreign material. If left unattended,
cover the pump with a protective layer of plastic.
Lubricate moving parts
During assembly, coat all moving parts with a film of clean hydraulic oil. This assures that these parts will
be lubricated during start-up.
Replace all O-Rings and gaskets
It is recommended that all O-rings be replaced. Lightly lubricate all O-rings with clean petroleum jelly
prior to assembly.
Repair Instructions
Series 45 Frame K2 Axial Piston Pumps
Introduction
4 | ©Danfoss | April 2017 AX00000305en-US0101

Secure the unit
For major repair, place the unit in a stable position with the shaft pointing downward. It will be necessary
to secure the pump while removing and torquing the endcap bolts.
Safety Precautions
Always consider safety precautions before beginning a service procedure. Protect yourself and others
from injury. Take the following general precautions whenever servicing a hydraulic system.
Unintended machine movement
W
Warning
Unintended movement of the machine or mechanism may cause injury to the technician or bystanders.
To protect against unintended movement, secure the machine or disable / disconnect the mechanism
while servicing.
Flammable cleaning solvents
W
Warning
Some cleaning solvents are flammable. To avoid possible fire, do not use cleaning solvents in an area
where a source of ignition may be present.
Fluid under pressure
W
Warning
Escaping hydraulic fluid under pressure can have sufficient force to penetrate your skin causing serious
injury and/or infection. This fluid may also be hot enough to cause burns. Use caution when dealing with
hydraulic fluid under pressure. Relieve pressure in the system before removing hoses, fittings, gauges, or
components. Never use your hand or any other body part to check for leaks in a pressurized line. Seek
medical attention immediately if you are cut by hydraulic fluid.
Personal safety
W
Warning
Protect yourself from injury. Use proper safety equipment, including safety glasses, at all times.
Repair Instructions
Series 45 Frame K2 Axial Piston Pumps
Introduction
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Symbols used in Danfoss literature
WARNING may result in injury Tip, helpful suggestion
CAUTION may result in damage to product or
property Lubricate with hydraulic fluid
Reusable part Apply grease / petroleum jelly
Non-reusable part, use a new part Apply locking compound
Non-removable item Inspect for wear or damage
Option - either part may exist Clean area or part
Superseded - parts are not interchangeable Be careful not to scratch or damage
Measurement required Note correct orientation
Flatness specification Mark orientation for reinstallation
Parallelism specification Torque specification
External hex head Press in - press fit
Internal hex head Pull out with tool – press fit
Torx head Cover splines with installation sleeve
O-ring boss port Pressure measurement/gauge location or
specification
The symbols above appear in the illustrations and text of this manual. They are intended to communicate
helpful information at the point where it is most useful to the reader. In most instances, the appearance
of the symbol itself denotes its meaning. The legend above defines each symbol and explains its purpose.
Repair Instructions
Series 45 Frame K2 Axial Piston Pumps
Introduction
6 | ©Danfoss | April 2017 AX00000305en-US0101

Auxiliary pad
If a second pump is used, you must remove it. You don’t need to remove auxiliary pads to remove the
end cap.
1. Remove the plate cover screws (J130) and remove the cover plate (J110).
2. Remove the coupling (J140) and the pad seal (J120). If you have an auxiliary B pad, discard the O-ring
(J120). The pad seal for an auxiliary A pad is reusable if undamaged.
3. Remove the auxiliary pad screws (J100) with an 8 mm internal hex wrench and remove the adapter
(J085).
4. Remove and discard the O-rings (J090, J095).
5. Remove the coupling (J140).
J140
J095
J100
J090
J085
J120
J110
J130
J140
J095
J100
J090
J085
J120
J110
J130
P109053
Item Wrench size
J130 9/16 inch
J110 8 mm internal hex
Repair Instructions
Series 45 Frame K2 Axial Piston Pumps
Disassembly
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Remove control
1. Using a 5 mm internal hex wrench, remove the 4 control screws (C300) that fasten the control
assembly to the endcap (J020).
2. Remove the control from endcap. Discard interface O-rings. (C200).
Remove control
C200
C300
P109056
Item Wrench size
C300 5 mm internal hex
Displacement limiter
1. Remove the adjustment seal/nut (L030).
The L030 adjustment seal/nut serves as a locking seal/nut, preventing the L040 screw from backing
out.
2. Remove the adjustment screw (L040). Remove plug (L010) with a 1 1/4 in. wrench. Discard the O-ring
(L010A).
L030
L010
L010A
L040
P109057
Repair Instructions
Series 45 Frame K2 Axial Piston Pumps
Disassembly
8 | ©Danfoss | April 2017 AX00000305en-US0101

Item Wrench size
L010 1 1/4 inch
L030 19 mm
L040 8 mm internal hex
Servo piston
Disassembly
1. Remove plug (L010) with a 1 1/4 in. wrench. Discard the O-ring (L010A).
2. Remove servo piston (P025) from housing.
P109065
Endcap and valve plate
1. Remove the 4 endcap screws (J030) using an 8 mm internal hex wrench.
Repair Instructions
Series 45 Frame K2 Axial Piston Pumps
Disassembly
©Danfoss | April 2017 AX00000305en-US0101 | 9

2. Remove the endcap. Remove the servo piston (L020) and guide (L080). Use care; valve plate (B070)
may adhere to inside surface. Discard O-rings (B045, B046). Refer to Inspection chapter for more
information.
B046
J030
J020
P109040
B070
J050
B020
J020
P109039
B010
J051
3. Slide the rear tapered roller bearing cone (B020) from the bottom end of the shaft. The bearing cup
(B010) may remain within the endcap.
Cylinder kit
1. Position pump on its side.
Repair Instructions
Series 45 Frame K2 Axial Piston Pumps
Disassembly
10 | ©Danfoss | April 2017 AX00000305en-US0101

2. Slide the cylinder block assembly (P010) out of the pump housing by pushing on the shaft. Push the
shaft only far enough so that the cylinder kit may be removed by hand. Keep track of the three small
hold-down pins (K046) located inside the cylinder kit.
Once removed, set the cylinder kit in a protected area. Contamination or scratches may lead to poor
performance or pump failure.
P109041
Input shaft and swashplate
1. Rotate the swashplate (B040) until level with pump housing.
2. Pull the shaft (J010) from the shaft seal and bearing kit.
3. Pull to remove the front tapered roller bearing (B050).
4. Carefully pry to remove the journal bearings (B030) and retaining pins (B071) from the pump housing.
Record the location and orientation of the journal bearings if they are to be reused. If necessary,
remove the front bearing cup (B060) from the pump housing.
Repair Instructions
Series 45 Frame K2 Axial Piston Pumps
Disassembly
©Danfoss | April 2017 AX00000305en-US0101 | 11

B060
B050
B040
J010
B030
B025
B071
P109042
Shaft seal
Repair Instructions
Series 45 Frame K2 Axial Piston Pumps
Disassembly
12 | ©Danfoss | April 2017 AX00000305en-US0101

Orient the housing with the flange facing up. Using snap-ring pliers, remove the snap ring (K010).
Carefully pry out the shaft seal (K020).
If you are unable to pull the shaft seal out, try to push the seal out by going through the inside of the
housing.
P109058
K010
K020
Control
C
CAUTION
If removing the LS or PC spool is not possible, be extremely careful when flipping or relocating the
housing so you do not lose or damage the spool.
PC only
Remove the plug (C103) and O-ring (C103A). Discard the O-ring. Remove the screw (C102). Remove the
spool (C132). Note the orientation of the spool for reinsertion. There may be differences in reinserting
into the same bore. Remove the adjusting screw (C138) and O-ring (C138A). Discard the O-ring. Remove
the springs (C134, C135) along with the spring guide (C133).
Disassemble the PC control
dC103A
C132 R
C133
C135
C134
dC138A
C138
C102
E101 193
C103
Repair Instructions
Series 45 Frame K2 Axial Piston Pumps
Disassembly
©Danfoss | April 2017 AX00000305en-US0101 | 13

PC/LS
Remove the 4 plugs (C103, C104, C105, C106) and their O-rings (C103A, C104A, C105A, C106A). Discard
the O-rings. Remove the 2 set screws (C102). Remove the spools (C112, C132). Note which bore each
spool came out of. Also note the orientation of each spool for reinsertion. There may be differences in
reinserting into the same bore.
Remove the adjusting screw (C138) and the O-ring (C138A). Discard the O-ring. Remove the springs
(C134, C135) and spring guide (C133).
Remove the adjusting screw (C118), O-ring (C116) and 2 backup rings (C117). Discard the O-ring and
backup rings. Remove the springs (C114, C115) and spring guide (C113).
Disassemble the PC / LS control
C112 R
C104
C103
C105
C105A
C106
C102
C113
C115
C114
C117 d
C116 d
C117 d
C118
C133
C135
C134
C138 E101 180
dC138A
RC132
dC103A
d
C106A
d
C104A d
Electric control
1. Remove four screws (C300).
2. Remove the control and discard the four O-rings (C200).
3. Remove set screws (C102), PC adjusting plug (C138) with O-ring (C138A), springs (C134, C135), and
seat (C133). Discard the O-ring if it is damaged.
4. Remove plug (C103). Remove PC spool (C132). Note orientation of the spool for reassembly.
5. Remove plug (G030), and orifice (G020).
6. Remove LS adjusting plug (C118), springs (C114, C115), and seat (C113).
7. Remove plug (C104), and spool (C112). Note the orientation of the spool for reassembly.
8. Remove four screws (C151). Remove the manifold (C152) and discard the two interface O-rings
(C154).
9. For electric proportional controls only:
Remove the electric control manifold drain orifice (C149).
Repair Instructions
Series 45 Frame K2 Axial Piston Pumps
Disassembly
14 | ©Danfoss | April 2017 AX00000305en-US0101

10. Remove plug (C153). Remove the cartridge valve nut (C125), electric solenoid (C155), and cartridge
valve (C150) from the electric control manifold.
Disassemble electric control
P108 668E
G020
G030
C200
C102
C103
C132
C112
C104
C300
C125
C155
C150
C149 C154
C152
C151
C113
C115
C133
C135
C114
C118
C134
C138A
C138
C153
Electronic Torque Limiting Control
Repair
Disassembly, inspection and reassembly steps are the same as the steps in the previous topic (Electric
Controls). This includes repair of the spools and plugs.
The solenoid (C155), nut (QC125), and O-rings (QC120) for the valve are available as separate repair
parts. The valve is only available as a complete assembly (QC150).
If it is necessary to remove the orifice (H020), use a 3 mm internal hex wrench. Torque it to 2.7 Nm [24
in-lb] when it is installed in the manifold.
Repair Instructions
Series 45 Frame K2 Axial Piston Pumps
Disassembly
©Danfoss | April 2017 AX00000305en-US0101 | 15

P108790
QC125
* Included in overhaul seal kit Q210
C155
QC150 QC120
C154
C149
C151
C152
H020
C153
*C200
C300
Item Description Wrench size Torque
C149 Orifice 3 mm internal hex 2.7 Nm [24 in-lb]
C151 Screws 6.4 Nm [4.7 lbf-ft]
C152 Manifold - -
C153 Plug 5 mm internal hex 12 Nm [8.9 lbf-ft]
C154 O-ring - -
C155 Solenoid - -
C200 O-rings - -
C300 Screws 6.4 Nm [4.7 lbf-ft]
QC120 O-rings
QC125 Nut 8.7 Nm [6.4 lbf-ft]
QC150 Valve assembly 27.7 Nm [20.4 lbf-ft]
H020 Manifold orifice 3 mm internal hex 2.7 Nm [24 in-lb}
Fan Drive Control
Disassembly
Use the wrench sizes and torques listed in the table.
1. Remove four screws (C300).
2. Remove the control and discard the 4 interface O-rings (C200).
3. Remove the coil plastic nut (QC125 ) Remove the coil.
Remember the correct coil connector orientation.
4. Remove the solenoid cartridge (C120). Remove O-ring (QC120).
5. Remove spring (C124) and spring guide (C123).
6. Remove the pressure limiter adjuster (C128).
7. Remove spring (C125) and spool (C122).
8. Remove plug (C107) and plug (C129).
9. Remove gain orifice (H030).
Repair Instructions
Series 45 Frame K2 Axial Piston Pumps
Disassembly
16 | ©Danfoss | April 2017 AX00000305en-US0101

10. Remove servo control orifice (G020).
P109024
Left coil orientation
Right coil orientation
C129
H030
*QC120
C124
C123
G020
QC135
QC130
QC125
C300
C107
C122
C125
C128B
C128A
C128 *C200
C120
C128C * Included in overhaul seal kit
Item Description Wrench size Torque
G020 Servo control orifice 3 mm internal hex 2.7 N•m [2 lbf•ft]
H030 Gain orifice 2,5 mm internal hex 2.7 N•m [2 lbf•ft]
C129 Plug 5/16" 1/8“ internal hex 6.2 N•m [4.67 lbf•ft]
C107 Plug 7/16" 3/16" internal hex 13.7 N•m [9.9 lbf•ft]
C128C Nut 9/16" 17 mm exter hex 23.7 N•m [17.5 lbf•ft]
C120 Solenoid cartridge 17 mm exter hex 25.75 N•m [19 lbf•ft]
QC125 Coil plastic nut 26 mm 12 pt socket 3.5 N•m [2 lbf•ft]
C300 Screws 4 mm internal hex 6.5 N•m [4.75 lbf•ft]
Cylinder block Kit disassembly
Disassemble the cylinder block kit
1. Pull to remove the slipper retainer (K049) with the pistons (K050) from the cylinder kit.
The pistons are not selectively fitted, however units with high hourly usage may develop wear
patterns. Number the pistons and bores for reassembly if they are to be reused.
2. Remove the ball guide (K047).
3. Remove the 3 pins (K046).
Most repairs do not require block spring removal. Perform this procedure only if you suspect
problems with the block spring.
Repair Instructions
Series 45 Frame K2 Axial Piston Pumps
Disassembly
©Danfoss | April 2017 AX00000305en-US0101 | 17

Disassemble the cylinder block kit
K050
K049
K047
K046
K041
K042
K043
K044
K045
P010
i
E101 012
l
R
Block spring removal
Turn the block over. Using a press, apply pressure on the block spring washer (K044) to compress the
block spring (K043). Compress the spring enough to safely remove the spiral retaining ring (K045).
While maintaining pressure, unwind the spiral retaining ring. Carefully release the pressure and
remove the outer block spring washer, block spring, and inner block spring washer (K042) from the
cylinder block.
W
Warning
Risk of personal injury: Compressing the block spring requires about 350 to 400 N [80 to 90 lbf]. Use a
press sufficient to maintain this force with reasonable effort. Ensure the spring is secure before
attempting to remove the spiral retaining ring. Release the pressure slowly after the retaining ring is
removed.
Repair Instructions
Series 45 Frame K2 Axial Piston Pumps
Disassembly
18 | ©Danfoss | April 2017 AX00000305en-US0101

Pistons and slippers
1. Inspect the pistons for damage and discoloration. Discolored pistons may indicate excessive heat; do
not reuse.
2. Inspect the running surface of the slippers. Replace any piston assemblies with scored or excessively
rounded slipper edges. Measure the slipper foot thickness. Replace any piston assemblies with
excessively worn slippers. Check the slipper axial end-play. Replace any piston assemblies with
excessive end-play.
Minimum slipper foot thickness and maximum axial end-play are given in the table to the right.
K2 Frame
Slipperfoot thickness 4.07 mm [0.16 in]
Piston/slipper end play 0.102 mm [0.004 in]
Inspect pistons
C103
Slipper
Maximum end play
Minimum
slipper foot
thickness
P104 109E
Ball Guide, Slipper retainer, and Hold-Down Pins
The ball guide should be free of nicks and scratches, and should not be excessively scored. Examine for
discoloration that may indicate excessive heat or lack of lubrication. The slipper retainer should be flat,
and slippers should fit in the retainer with minimal side play. Place the hold-down pins on a flat surface
and roll them to make sure they are straight. Discard and replace any damaged parts.
Inspect guide, retainer, and pins
i
Slipper
retainer
Ball guide
Hold down pins
P101 471
Block spring, and washers
If cylinder kit was fully dissembled, visual inspection of the cylinder block, spring, and washers should
indicate minimal wear. Replace if cracks or other damage is present.
Repair Instructions
Series 45 Frame K2 Axial Piston Pumps
Inspection
©Danfoss | April 2017 AX00000305en-US0101 | 19

Inspect block spring and washers
i
Washer
Cylinder block spring
Spring retainer
Retaining ring
P101 472
Cylinder block
Examine the running face of the cylinder block. The surface should be smooth and free of nicks and
burrs. Ensure that no scratches or grooves exist; these may drastically reduce output flow.
K Frame 38 cc 45 cc
Minimum cylinder block height (A) 56.48 mm
[2.224 in]
Maximum block bore diameter (B) 16.44 mm
[0.65 in]
17.98 mm
[0.71 in]
Inspect cylinder block
C100
A
flat to 0.002 mm
[flat to 0.000080 in]
P101 358
Control
Carefully examine the PC (and LS) plug(s) for signs of wear. Also check the small tip of the plug(s) for
heavy wear and replace if necessary. Inspect each spool’s springs to make sure they are intact. Check the
inside and outside surfaces of the springs for wear and replace if necessary. Check the spool’s outside
diameter for scratches and / or burrs. Clean and coat all spools, bores, and seals with a light coating of
hydraulic oil.
Repair Instructions
Series 45 Frame K2 Axial Piston Pumps
Inspection
20 | ©Danfoss | April 2017 AX00000305en-US0101