General Pump T16A-18A-20A-22A User Manual

KT16A/18A/20A/22A

8

Repair Manual

KT16A, KT18A, KT20A, KT22A

General Pump is a
member of the
Interpump Group

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GENERAL PUMP

A member of the Interpump Group

KT16A/18A/20A/22A SERIES

INDEX

1. INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Page 3

2. REPAIR INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Page 3

2.1 Repairing Mechanical Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Page 3

2.1.1 Disassembly of Mechanical Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . .Page 4

2.1.2 Reassembly of Mechanical Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . .Page 6

2.1.3 Increase and Reduction Classes . . . . . . . . . . . . . . . . . . . . . . . . . . . .Page 8

2.1.4 Disassembly / Reassembly of Bearings and Shims . . . . . . . . . . . . . .Page 8

2.2 Repairing Hydraulic Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Page 11

2.2.1 Dismantling the Head-Valve Units . . . . . . . . . . . . . . . . . . . . . . . . . . .Page 11

2.2.2 Reassembling the Head-Valve Units . . . . . . . . . . . . . . . . . . . . . . . . .Page 13

2.2.3 Dismantling the Head-Seals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Page 15

2.2.4 Dismantling the Piston Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Page 16

2.2.4 Assembling the Head - Seals - Piston Unit . . . . . . . . . . . . . . . . . . . . .Page 17

3. SCREW CALIBRATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Page 18

4. REPLACING THE CON-ROD FOOT BUSHINGS . . . . . . . . . . . . . . . . . . . . . . . . .Page 19

5. REPAIR TOOLS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Page 20

6. MAINTENANCE LOG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Page 21

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GENERAL PUMP

A member of the Interpump Group

KT16A/18A/20A/22A SERIES

1. INTRODUCTION

This manual describes the instructions for repairing KT Series pumps, and must be carefully read and
understood before performing any repair intervention on the pump. Proper pump operation and longevity
depend on the correct use and maintenance. General Pump declines any responsibility for
damage caused by the misuse or the non-observance of the instructions described in this manual.

2. REPAIR INSTRUCTIONS

2.1 Repairing Mechanical Parts

Mechanical parts repair must be performed after removal of oil from the casing. To drain
the oil, remove the oil dipstick, (1, fig. 1) and then the draining plug (2, fig. 1).

The oil must be placed in a suitable container and disposed of in special centers.
It absolutely must not be discarded into the environment.

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2.1.1 Disassembly of Mechanical Parts

The operations described must be performed after removing the hydraulic part, ceramic pistons and
splash guards from the pump (paragraphs 2.2.3, 2.2.4).

Remove in the following order:

• The pump shaft tab

• The rear cover

• The connecting rod cap as follows:
unscrew the cap fixing screws, remove the con-rod caps with their lower half-bearings (fig. 2)
paying atention to the numbered sequence during disassembly.

To avoid possible errors, caps and con-ro shanks have been numbered on one side (1, fig. 2/a).

A member of the Interpump Group

KT16A/18A/20A/22A SERIES

- The side covers using - for extraction 3 fully threaed M6 x 50 screws, inserting them in the

threaded holes as indicated in fig. 3

- Push the piston guides forward with their con-rods to facilitate side extraction of the pump as

indicated in fig. 4.

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GENERAL PUMP

• Remove the pump shaft

• Complete the disassembly of the con-rod units by removing them from the pump casing and
removing the piston guide pins

• Remove the pump shaft seal rings using common tools

• Remove the piston guide seal rings as described below:

A member of the Interpump Group

KT16A/18A/20A/22A SERIES

Use the extractor, p/n F26019400 (1, fig. 5) and the gripper, p/n F27503800 (2, fig. 5). Insert the gripper as
far as possible onto the seal ring with the aid of a hammer (fig. 5/a), subsequently screwing the extractor to
the gripper, and use the extractor hammer (fig. 5/b) until the ring to be replaced is removed (fig. 5/c).

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GENERAL PUMP

2.1.2 Reassembly of mechanical parts

After having checked that the casing is clean, proceed with assembly of the mechanical part as described
below:

• Assemble the upper and lower half-bearings in their seats in the con-rods and caps.

Make sure that the reference marks on the upper half-bearing (1, fig. 6) and lower half­bearings (2, fig. 6/a) are positioned in their respective seats in the con-rod and cap.

A member of the Interpump Group

KT16A/18A/20A/22A SERIES

• Insert the piston/con-rod guide units into the pump casing, directing the numbering on the con-rod

shank towards the top of the casing.

To facilitate pump chaft insertion (without the tab), it is essential to repeat the operation performed during
disassembly, pushing the piston/con-rod guide units as far down as possible (paragraph 2.1.1).

• Before assembling the side cover on the PTO side, check the conditions of the radial ring lip seal

and relative contact area on the shaft.

If replacement is necessary, position the new ring using tool p/n F27904500 as incicated in fig. 7

If the pump shaft shows diametrical wear in the area of contact with the lip seal, in order to
prevent the grinding operation, it is possible to reposition the ring in abutment with the cover
as shown in fig. 7.

Before assembling the side covers, make sure there are O-rings on both of them and shim rings on
the indicator side cover only. To facilitate filling of the first section and relative insertion of the covers on
the casing, we recommend using three partially threaded M6x40 screws (1, fig. 8), then completing the
operation with the screws supplied (M6x16).

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GENERAL PUMP

• Couple the con-rod caps to their shanks, referring to the numbering (1, fig. 9).

Note the correct assembly direction of the caps.

Fasten the caps to their respective con-rod shanks by means of M8x1x42 screws (fig. 10) lubricating both the
underhead and the threaded shank, proceeding in two stages:

1. Manually turn the screws until they begin to tighten

2. Tightening torque: 22 Ft. Lbs. (30 Nm)
Alternatively, ensure:

1. Pre-tightening torque: 7-11 Ft. Lbs. (10-15 Nm)

2. Tightening torque: 22 Ft. Lbs. (30 Nm)

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KT16A/18A/20A/22A SERIES

• After having completed tightening operations, check that the con-rod head has a side clearance in
both directions.

• Assemble the new piston guide seal ring with the relative seats on the pump casing (fig. 11)
following the procedure described:

Using tool p/n F27904200 composed of a tapered bushing and a buffer, screw the tapered bushing into the
hole in the piston guide (fig. 11a), insert the new seal ring on the buffer as far as it will go (determined by
the height of the buffer) into its seat on the pump casing (fig. 11b), remove the tapered bushing (fig. 11/c).

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