Danfoss PAH 50 User manual

521B1072 DKCFN.PI.011.NC3.02 09 -2013
INSTRUCTIONS
Servicing PAH 50 - 100
180R9098 180R9098
Note: If the pump is dismantled during the warranty
period, the pump is no longer under warranty.
Dismantling:
1. Tools required for dismantling the PAH 50 - 100 pump.
2. Remove parallel key and unscrew front screw M6 (10 mm key).
3. Unscrew screws in front ange.
4. Remove front ange.
5. Remove shaft seal using two screwdrivers.
6. Remove guide pin from housing and the two guide pins from
swash plate.

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DKCFN.PI.011.NC3.02 521B1072
7. Remove swash plate using the 4 mm front screw.
8. Remove cylinder barrel from housing.
9. Unscrew the eight screws M8 in port ange (6 mm key).
10. Separate housing and port ange.
11. Remove valve plate from port ange.
12. Remove guide pins and guide.

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521B1072 DKCFN.PI.011.NC3.02
13. Remove pistons.
14. Remove retaining plate.
15. Remove retaining ball.
16. Remove thrust plate using two screwdrivers.
17. Remove shaft sealing from front ange.
18. The ceramic ring removed from the front ange.
19. Wash all parts and replace all seals (inclusive shaft seal).
20. Inspect all parts carefully (see "Inspection") and replace any worn
parts.
21. If the pump has failed, the reason for the failure must be found
and xed before the repaired pump is re-installed.

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DKCFN.PI.011.NC3.02 521B1072
Housing with bearing
Washer and screw
(for xing swash plate)
Retaining ball
Shaft seal
Thrust plate
with sealings
Pistons
Retaining plate
Cylinder barrel
Port ange
Key
Screws for anges
Ceramic ring
Retaining guide
Port plate
Five guide pins Swash plateO-rings
Front ange

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521B1072 DKCFN.PI.011.NC3.02
Inspection:
Port plate and thrust plate
1. Neither port plate nor thrust plate must show any sign of wear.
2. Hold a ruler against surface of plate and check tightness against a
light source.
3. Check that both O-rings and back-up rings are not broken and do
not show severe wear.
Pistons
1. Play in ball and socket joint must not exceed 0.1 mm.
2. Thickness of piston shoes must be at least 4.4 mm.
3. Hold a ruler against surfaces of piston shoes to check that the
surfaces are even and smooth and without any scratches.
4. Pumps for technical water only:
It is acceptable that the (black) treated surfaces of the pistons are
partly worn.

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DKCFN.PI.011.NC3.02 521B1072
Cylinder barrel:
1. Check outer bearing surface for large wear grooves (not critical).
2. Check that bushings are free from seizure and large scratches.
3. Ensure that pistons can move freely in bushings.
Housing:
1. Check bearing (black) for large wear grooves (not critical).

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521B1072 DKCFN.PI.011.NC3.02
Swash plate:
1. Check that surface of swash plate is smooth and without any large
scratches (depth more than 0.1 mm).

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DKCFN.PI.011.NC3.02 521B1072
Assembly:
1. Parts and tools required for assembly.
2. Check that all parts are OK. Replace all seals.
3. Mount O-ring, guide and guide pins on port ange.
4. Mount valve plate in its right position using pin as guide.
5. Mount housing using pin as guide.
6. Place housing and port ange near table edge and mount screws
from below.
7. Mount thrust plate with sealings on cylinder barrel.

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521B1072 DKCFN.PI.011.NC3.02
8. Press thrust plate into cylinder barrel using a table or the like as
support.
9. Mount cylinder barrel in housing.
10. Slide retaining ball (smallest diameter pointing upwards) down the
shaft.
11. Mount retaining plate (smallest centre diameter pointing upwards).
12. Mount pistons.
13. Mount ceramic ring on the tool.
14. Mount ceramic ring by pressing tool as far down in front ange as
possible.

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DKCFN.PI.011.NC3.02 521B1072
15. Push tool through front ange.
16. Mount shaft seal (carbon surface pointing downwards), spring, and
washer (edge pointing downwards) by sliding them over the tool.
17. Mount swash plate on front ange using pins as guide.
18. Press swash plate against front ange and screw tools together.
19. Mount O-ring on front ange.
20. Mount washer and screw in front ange to x swash plate.
21. Tighten screw to a torque of 8 Nm and remove tool.
Shaft seal
Washer
Spring

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521B1072 DKCFN.PI.011.NC3.02
22. Mount tool over shaft.
23. Mount front ange on te housing using pin as guide.
24. Remove tool.
25. Mount screws (eight M8) in front ange.
25. Tighten screws to a torque of 30 Nm and mount parallel key on
shaft.
Guide pin

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DKCFN.PI.011.NC3.02 521B1072
180B4121 - Shaft seal 180B4122 - Valve plate 180B4125 - Piston kit (standard pump) 180B4123 - Piston kit (tech. water pump) 180B4126- Cylinder barrel; (standard pump) 180B4124- Cylinder barrel; (tech. water pump) 180Z0237 - Shaft seal tool set
Pos. Qnt. Unit Designation Material
- 1 Pc. Shaft bush, torpedo - X
- 1 Pc. Press tool for 35 mm shaft - X
- 1 Pc. Mounting screw -X
4 1 Pc. Shaft seal AISI304/NBR X
5 1 Pc. Housing AISI304
6 1 Pc. Swash plate Stainless steel (1.4057)
7 5 Pcs. Pin AISI304 X
10 1Pc. Retaining plate AISI304 X X
11 9Pcs. Piston Stainless steel (1.4057) X X
12 9Pcs. O-ring NBR X
13 9Pcs. Back-up ring PEEK X
14 1Pc. Thrust plate Stainless steel (1.4057) X
16 1Pc. Retaining ball Stainless steel (1.4057) X X
17 1Pc. Cylinder barrel Stainless steel (1.4057) X X
18 1Pc. Spring Stainless steel (1.4068) X X
19 1Pc. Spring guide PEEK X X
20 1Pc. Cir clips Stainless steel X X
21 1Pc. Valve plate AISI304/PEEK X
22 1Pc. Pin AISI304
24 1Pc. O-ring NBR X
25 1Pc. Port ange AISI304
26 12 Pcs. Screw AISI304 X
27 1Pc. Bleed screw AISI304
28 2Pc. Bleeding instruction AISI304
29 2Pcs. Screw AISI304
30 1Pc. Key AISI302 X
31 1Pc. Plug Polymer
32 1Pc. Plug Polymer
33 1Pc. Sealing NBR X
34 1Pc. Screw AISI304 X
35 1Pc. Front ange NBR
36 2Pcs. O-ring NBR
- 1 Pc. Service instruction (180R9098) X X X X X X
Service kit list for PAH 50 - 100

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521B1072 DKCFN.PI.011.NC3.02
Exploded view PAH 50 -100