2. Disassembling the pump .............................................................................................................................................. 3
3. Assembling the pump .................................................................................................................................................... 7
4. Disassembling and assembling of the swash plate ...........................................................................................13
5. Disassembling and assembling of cylinder barrel and valve plate ..............................................................14
6. Disassembling and assembling of the ushing valve ......................................................................................15
7. How to replace the shaft seal.....................................................................................................................................15
9. Spare parts list APP S (674) 5.1-9.0 ...........................................................................................................................20
9.1 Exploded view APP S (674) 5.1-9.0 ...........................................................................................................................21
10. When should the pistons be replaced ....................................................................................................................22
This document covers the instructions for disassembling and assembling the axial piston pumps
APP S 5.1-9.0 / APP S 674 5.1-9.0
Important: It is essential that the pump is
serviced in conditions of absolute cleanliness.
For a better understanding of the pump, please
see the exploded view in item 9.
Note:
For disassembling and assembling it must be
possible to place the pump vertically with the
shaft pointing downwards. This can be done
with a distance block with a minimum height
of 50 mm.
Tools needed:
• 10 mm combination wrench
• 13 mm combination wrench
• Torque wrench
• 2 screwdrivers
• 1 press bush tool
• Adjustable pin wrench
• Distance block
Note:
This document covers dierent pump sizes.
Therefore the images shown in the instruction
may dier from your actual pump and parts,
however, the priciples of disassembling/
assembling will be the same.
Instruction | Disassembling and assembling APP S 5.1-9.0 / APP S 674 5.1-9.0
2. Disassembling the
pump
1. Disconnect the pump from the rest of the
system.
3. Carefully remove the stop bush ring and
the O-ring with a screwdriver.
2. Lubricate shaft with clean ltered water.
4. Using a 10 mm combination wrench,
unscrew the four bolts from shaft seal
cover.
WARNING!
While unscrewing the bolts with one
hand hold the shaft seal cover with the
other hand. This is done to ensure, the
cover does not pop out and damage the
ceramic ring.
Instruction | Disassembling and assembling APP S 5.1-9.0 / APP S 674 5.1-9.0
12. Using a 13 mm combination wrench,
remove all the bolts on the mounting
ange except the two shown in item 13.
13. Unscrew the remaining two bolts. Turn
each bolt one round at the time to make
sure that the ange is removed as straight
upward as possible.
14. Remove end ange.
16. Remove the pistons one by one. Be careful
not to scratch the pistons. Tilt the retainer
plate to horizontal position for easy
removal of pistons, if required.
WARNING:
Do not use any tools.
15. Swash plate must be placed so that its
surface is not scratched. For further
disassembling of swash plate, see page 13.
Instruction | Disassembling and assembling APP S 5.1-9.0 / APP S 674 5.1-9.0
19. Remove the retainer ball.
20. Pull the cylinder barrel straight upwards in
a continuous lift to ensure no damage of
house bearing. This can only be done if the
shaft seal is removed.
WARNING:
If the cylinder barrel is dropped or
lowered too fast into housing, the main
bearing/shaft bearing might be
damaged.
20. Remove the retainer guide and the spring.
21. Place cylinder barrel upside down. For
further disassembling of cylinder barrel
and valve plate see page 14.