Danfoss MAH Series User manual

Service guide
MAH motor
MAH 6.3 - 12.5
Disassembling and assembling
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Service guide | Disassembling and assembling MAH 6.3 - 12.5
2180R9152 | AX357937856579en-000402 | 07.2021
NOTE: If the motor is disassembled within the warranty period, the motor is no longer covered
by the warranty.
Introduction
Table of Contents Introduction.......................................................................................................................................... 2
1. Disassembling the motor ................................................................................................................. 3
2. Inspection.............................................................................................................................................. 7
3. Assembling the motor ........................................................................................................................ 8
4. Service kit for MAH 6.3 ..................................................................................................................... 13
4.1. Service kit for MAH 12.5 ................................................................................................................... 14
5. Exploeded view MAH 6.3 ................................................................................................................ 15
5.1. Exploded view 12.5 ...........................................................................................................................16
This document covers the instructions for
disassembling and assembling the motor
MAH 6.3 - 12.5
Tools needed for disassembling/assembling the MAH 6.3 - 12.5 motor

Service guide | Disassembling and assembling MAH 6.3 - 12.5
3
180R9152 | AX357937856579en-000402 | 07.2021
1. Disassembling the
motor
2. Dismantle front cover using a vice.1. Remove parallel key and unscrew front
cover.
3. Remove shaft seal using two screwdrivers.
4. Remove the two small O-rings from
ange.Removesealfromfrontcoverusing
a screwdriver.
5. Unscrew the four screws for housing. 6. Remove housing.

Service guide | Disassembling and assembling MAH 6.3 - 12.5
4180R9152 | AX357937856579en-000402 | 07.2021
7. Remove pistons and retaining plate from
cylinder barrel.
8. Remove retaining guide.
10. Remove cylinder barrel.9. Remove pins and springs.
12. Remove guide pin.11. Remove port plate from  ange.

Service guide | Disassembling and assembling MAH 6.3 - 12.5
5
180R9152 | AX357937856579en-000402 | 07.2021
14. Remove O-ring from port.13 Remove O-ring from ange..
15. Loosen thrust plate using a screwdriver.
Place screwdriver in slot of thrust plate.
16. Remove swash plate from housing.
17. Wash all parts and replace all seals
(inclusive shaft seal).
Inspect allpartscarefully(see ”Inspection”)
and replace any worn parts.
If the motor has failed, the reason for the
failure must be found and  xed before the
repaired motor is re-installed.

Service guide | Disassembling and assembling MAH 6.3 - 12.5
6180R9152 | AX357937856579en-000402 | 07.2021
Thrust plate with sealing Swash plate Housing
Cylinder barrel
Retaining
guide
Front cover
Pins and springs
Seal
Flange
Pistons
Port plate
Retaining plate
O-rings
Pins
Screws and washers Shaft seal Washer Spring
18. Parts

Service guide | Disassembling and assembling MAH 6.3 - 12.5
7
180R9152 | AX357937856579en-000402 | 07.2021
2. Hold a ruler against the surface of the
plates and check the tightness against a
light source.
1. Neither port plate nor thrust plate must
show any sign of wear.
2. Inspection 2.1. Port plate and thrust plate
2. Hold a ruler against the surfaces of the
piston shoes to check that the surfaces
are even and smooth and without any
scratches.
2.2. Pistons
1. The thickness of the piston shoes must be
at least 3.4 mm.
The play in the ball and socket joint must
not exceed 0.1 mm.
2.3 Cylinder barrel
1. Check outerbearingsurfaceforlargewear
grooves (not critical).
Check that bushings are free from seizure
and large scratches.
Ensure that pistons can move freely in
bushings.
1. Check that swash plate surface is smooth
and without any big scratches (depth
more than 0.1 mm).
2.4 Housing

Service guide | Disassembling and assembling MAH 6.3 - 12.5
8180R9152 | AX357937856579en-000402 | 07.2021
1. Mount O-ring on ange. 2. Mount guide pin.
WARNING:
Do not use silicone when assembling the
motor. Do not reuse disassembled O-rings;
they might be damaged. Always use new
O-rings.
3. Assembling
Important:
It is essential that the motoris serviced in
conditions of absolute cleanliness. All parts
must be absolute clean before mounting.
4. Mountportplateinitsrightpositionusing
pin as guide.
3. Mount the O-ring in port.
Guide pin

Service guide | Disassembling and assembling MAH 6.3 - 12.5
9
180R9152 | AX357937856579en-000402 | 07.2021
5. Mount thrust plate with seals on cylinder
barrel. 6. Check that the gap between the cylinder barrel and the thrust plate is 1.5-2.5 mm.
1.5 - 2.5 mm
7. Mount the cylinder barrel in the ange. 8. Assemble pins and springs.
9. Mount pin/spring assemblies. 10. Mount the retainer guide.

Service guide | Disassembling and assembling MAH 6.3 - 12.5
10 180R9152 | AX357937856579en-000402 | 07.2021
12. Insert the pistons.
11. Mount the retaining plate on the retainer
guide with plain surface pointing upwards.
14. Mount housing using pin as guide.
13. Mount swash plate.
16. Mount the two O-rings in the ange.15. Tighten screws to a torque of 13 Nm.