Danfoss APP 1.5 User manual

Service guide
APP pumps
APP 1.5 - 3.5
Disassembling and assembling
hpp.danfoss.com

Service guide |Disassembling and Assembling, APP 1.5-3.5
© Danfoss | DCS (im) | 2017.082 | 180R9091 | DKCFN.PI.013.EF5.02 | 521B0741
Table of Contents
NOTE: If the pump is disassembled within the warranty period, the pump is no longer covered
by the warranty.
Introduction
This document covers the instructions for
disassembling and assembling the axial piston
pump APP 1.5-3.5
Tools needed:
• Shaft seal tool (code no. 180B4148)
• Press bush
• Allen key 5mm
• 2 Screwdrivers
Important: It is essential that the pump is
serviced in conditions of absolute cleanliness.
To understand the pump design better, please
see exploded view on last page.
WARNING: Do not reuse disassembled O-ring
or shaft seal as they might be damaged.
Contents
Introduction ................................................................................................................................................................................2
1. Disassembling and assembling the pump.............................................................................................................3
2. Change of shaft seal .......................................................................................................................................................7
3. Exploded views..............................................................................................................................................................10
3.1 APP 1.5-2.5 ......................................................................................................................................................................10
3.2 APP 3.0-3.5 ......................................................................................................................................................................11

Service guide | Disassembling and Assembling, APP 1.5-3.5
© Danfoss | DCS (im) | 2017.08 180R9091| DKCFN.PI.013.EF5.02 | 521B0741| 3
1. Disassembling and
assembling the pump
2. Wet the shaft and shaft seal with clean
(filtered) soap water. Gently lever the shaft
seal assembly free using 2 screwdrivers.
4. Carefully turn the whole pump over so
that the shaft is facing down. Support the
pump in a suitable hollow base so that the
pump is not supported by the shaft.
6. Remove the pistons, retaining plate,
retaining ball, spring guide, and spring
from the cylinder barrel.
1. Unscrew the 4 mounting screws and
remove seal SAE flange.
Do not yet unscrew the 2 lower screws.
3. Unscrew the 2 lower screws.
5. Remove the housing.
APP 1.5-2.5
APP 3.0-3.5

Service guide |Disassembling and Assembling, APP 1.5-3.5
© Danfoss | DCS (im) | 2017.084 | 180R9091 | DKCFN.PI.013.EF5.02 | 521B0741
8. Remove the port plate.
10. Replace the O-rings and the back-up rings
on the valve plate. Mount the new back-
up rings on the new valve plate first and
then mount the new O-rings.
Wet the O-rings and back-up rings with
clean (filtered) soap water.
9. Gently lever the valve plate assembly free
with the aid of a screwdriver.
11. Gently press, by hand, the valve onto the
cylinder barrel.
Mount backup
ring first
Then mount
O-ring
7. Remove the cylinder barrel.
12. Gently push flushing valve out using the
Allen key.

Service guide | Disassembling and Assembling, APP 1.5-3.5
© Danfoss | DCS (im) | 2017.08 180R9091| DKCFN.PI.013.EF5.02 | 521B0741| 5
16. Mount flushing valve by pressing it into
the hole.
15. Turn flushing valve upside down. If not
properly assembled, spring will fall out.
18. Replace the O-ring on the port flange and
position the new cylinder barrel on the
port plate.
13. Remove spring from poppet and poppet
guide and remove O-ring from poppet
guide.
17. Position the port plate over the guide pin.
IMPORTANT: Make sure that the guide
pin is located in the locating hole in the
port plate
Locating hole
Guide pin
14. Press new spring onto shoulders of
poppet guide and poppet so it is stuck
on both collars. Then mount new O-ring
on poppet guide.
O-ring

Service guide |Disassembling and Assembling, APP 1.5-3.5
© Danfoss | DCS (im) | 2017.086 | 180R9091 | DKCFN.PI.013.EF5.02 | 521B0741
21. Hold the pump together and carefully
turn it over to rest on the housing. To
prevent seizing-up, lubricate the threads
on the w screws and screw them into the
port flange and he housing. Use Molykote
D paste from Dow Corning or Klüber
UH1 84-201 from Klüber lubrication.
Tighten the 2 flange screws ato a torque
ccording to exploded view.
19. Positionthenewspring,newspringguide,
newretainerguide,newretainerplateand
new pistons.
24. Lubricate the threads on the 4 screws
with grease and screw them into the
pump and tighten by hand. Use Molykote
D paste from Dow Corning or Küber UH1
84-201 from Küber Lubrication.
23. Replace the O-ring on the SAE flange.
20. Position the housing on the port flange
and over the guide pin.
22. Mount the new shaft seal following the
instructions on the next pages.
Wet torpedo and new shat seal with
soap. Do not use silicone grease.
Slide the shat seal over the torpedo with
carbonsealfreeface pointingupwards.Be
careful not to damage the carbon seal
facon on the shaft seal.

Service guide | Disassembling and Assembling, APP 1.5-3.5
© Danfoss | DCS (im) | 2017.08 180R9091| DKCFN.PI.013.EF5.02 | 521B0741| 7
2. Change of shaft seal
1. Unscrew the 4 mounting screws and
remove the seal SAE flange.
Do not unscrew the 2 recessed screw at
this time.
Tools needed
2. Wet the shaft and shaft seal with
clean (filtered) soap-water. Gently lever
theshaftsealassemblyfreewiththeaidof
2 screwdrivers.
3. Fit the hollow bush (torpedo) to the shaft.
Wet the torpedo and replacement shaft
seal with soap. Do not use silicone
grease.
Recessed
screws
Recessed
screws
4. Slide the shaft seal over the torpedo with
the carbon seal face pointing upwards. Be
careful not to damage the carbon seal
face on the shaft seal.

Service guide |Disassembling and Assembling, APP 1.5-3.5
© Danfoss | DCS (im) | 2017.088 | 180R9091 | DKCFN.PI.013.EF5.02 | 521B0741
7. Push the new ceramic ring into the flange
using the plastic tool provided. Make sure
the face with the rubber seal is positioned
against the shoulder in the flange.
Wet the parts with clean (filtered) soap-
water before assembly.
9. To prevent cold welding, lubricate
threads on the 4 screws with grease and
screw them into the pump and tighten
byhand.UseMolykote®DpastefromDow
Corningor KlüberUH184-201fromKlüber
lubrication. Tighten the 4 flange screws
according to exploded view.
6. Remove ceramic ring from the flange.
8. Position the O-ring on the seal SAE flange.
5. Using the plastic tool provided, large
diameter first, press the seal home against
the shoulder, by hand.

Service guide | Disassembling and Assembling, APP 1.5-3.5
© Danfoss | DCS (im) | 2017.08 180R9091| DKCFN.PI.013.EF5.02 | 521B0741| 9

Service guide |Disassembling and Assembling, APP 1.5-3.5
© Danfoss | DCS (im) | 2017.0810 | 180R9091 | DKCFN.PI.013.EF5.02 | 521B0741
3. Exploded views 3.1 APP 1.5-2.5