Danfoss App 11-13 User manual

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Instruction

Changing pistons

APP 11-13 and

APP 16-22

MAKING MODERN LIVING POSSIBLE

Instruction Changing pistons APP 11-13 and APP 16-22

180R9227 / 521B1194 / DKCFN.PI.013.O1.02 / 03.2012

Contents

1. Disassembling

This document covers the instructions for

changing the pistons on the axial piston pumps

APP 11-13 and APP 16-22.

Note: It is essential that the pump is serviced in

conditions of absolute cleanliness.

Tools needed are:

• 13 mm combination wrench

• 6 mm allen key

Service kit see parts list 521D0941.

1. Disconnect the pump from the system, or

close all connection pipes (water supply).

Bleed water from the pump.

2. Loosen all screws on the pump except the

3 screws as shown in the picture below,

using the 13 mm combination wrench.

WARNING:

Never unscrew the 2 screws marked with

coloured sealer.

1. Disassembling ..........................................................................3

2. Assembling .............................................................................5

3. When should the pistons be replaced?...................................................7

Instruction Changing pistons APP 11-13 and APP 16-22

180R9227 / 521B1194 / DKCFN.PI.013.O1.02 / 03.2012

3. Unscrew the remaining 3 screws using the

combination wrench and turn each screw a

couple of rounds at the time, to ensure the

swash plate is loosened as straight

backwards as possible.

Note: There is nothing to hold the swash plate!

4. Remove the ange/swash plate carefully.

5. Place the swash plate upside down to avoid

scratches on the surface.

6. Carefully remove the pistons one by one.

Instruction Changing pistons APP 11-13 and APP 16-22

180R9227 / 521B1194 / DKCFN.PI.013.O1.02 / 03.2012

7. It is recommended to place the pistons

upside down on an even clean base/

surface.

Warning: Ensure that the piston shoes

and piston surfaces are not damaged or

scratched during removal.

8. Remove the retainer plate.

9. Inspect the piston bushings in the cylinder

barrel for scratches or other damages.

Small scratches are accepted if there are no

hard particles in the bushings.

10. If any worn pistons are found, all pistons

must be replaced. See page 7.

Instruction Changing pistons APP 11-13 and APP 16-22

180R9227 / 521B1194 / DKCFN.PI.013.O1.02 / 03.2012

2. Assembling Important: It is essential that the pump is

serviced in conditions of absolute cleanliness.

All parts must be absolute clean before

mounting.

1. Carefully push the retainer plate in place. 2. Ensure that the retainer plate is oriented

correctly with its slant surfaces pointing

downwards.

3. Insert all the pistons randomly. Note: Tilt the retainer plate for easy insert of

the swash plate. Place pin in the housing.

Instruction Changing pistons APP 11-13 and APP 16-22

180R9227 / 521B1194 / DKCFN.PI.013.O1.02 / 03.2012

4. Replace the O-ring on the mounting ange. 5. Carefully insert the swash plate into the

housing.

9. Bleed the pump.

10. Follow the start-up procedure, see

instruction 180R9223.

6. Mount the 3 screws as shown below. Turn

each screw a couple of rounds at the time,

to ensure the swash plate is pulled as

straight forward as possible.

Note : Be careful not to squeeze/damage

the O-ring.

7. Insert the remaining screws and cross

tighten them to a torque of 30 Nm

+/- 3 Nm.

8. Connect the pump to the rest of the

system.

Instruction Changing pistons APP 11-13 and APP 16-22

180R9227 / 521B1194 / DKCFN.PI.013.O1.02 / 03.2012

3. When should the

pistons be replaced?

This section provides guides on how to deter-

mine whether the pistons of APP 11-13 and 16-22

are worn and should be replaced.

Note: If the pistons break down, the pump will

suer a disastrous breakdown.

In case of doubt – the pistons must be replaced.

If any worn pistons are found, all pistons must be

replaced.

The pictures below are meant as guideline for

evaluating the wear of the sliding surface.

1. No wear or cavitation of the piston shoe.

New inspection is required within

4,000 hours.

2. Cavitation of the piston shoes.

New inspection is required within

2,000 hours.

3. Cavitation of the piston shoes.

All pistons must be replaced within

the next 1,000 hours.

Instruction Changing pistons APP 11-13 and APP 16-22

180R9227 / 521B1194 / DKCFN.PI.013.O1.02 / 03.2012

Danfoss can accept no responsibility for possible errors in catalogues, brochures and other printed material. Danfoss reserves the right to alter its products without notice.

This also applies to products already on order provided that such alterations can be made without subsequential changes being necessary in specications already agreed.