General Pump LK Repair Manual

LLKK

Repair Manual

LK50-LK55-LK60

LK36-LK40-LK45

GENERAL PUMP

INDEX

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

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

2.1 Repair of the Mechanical Part . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Page 3

2.1.1 Dismantling the Mechanical Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . .Page 4

2.1.2 Assembling the Mechanical Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . .Page 15

2.1.3 Classes of Increase . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Page 31

2.2 Repair of the Hydraulic Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Page 31

2.2.1 Head Disassembly - Valve Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Page 31

2.2.2 Head Assembly - Valve Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Page 35

2.2.3 Disassembling the Plunger Unit - Supports - Seals . . . . . . . . . . . . . .Page 41

2.2.4 Assembly of the Plunger Unit - Suports - Seals . . . . . . . . . . . . . . . . .Page 44

3. SCREW CALIBRATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Page 48

4. REPAIR TOOLS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Page 49

5. MAINTENANCE LOG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Page 50

A member of the Interpump Group

LK SERIES

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GENERAL PUMP

A member of the Interpump Group

LK SERIES

1. INTRODUCTION

This manual contains the instructions for repairing LK Series pumps, and must be carefully read and
understood before performing any repair intervention on the pump. Correct use and adequate maintenance is
fundamental for the pump’s regular operation and long wear. 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 Repair of the Mechanical Parts

Repairs on the mechanical parts must be carried out after removing the oil from the crankcase. To remove the
oil, remove the oil fill plug, pos. 1, fig. 1 and then the drain plug, pos. 2, fig.1 present on both side of the
crankcase.

Exhausted oil must be collected in an appropriate container and disposed of in
an authorized location. Do not under any circumstances discard into the environment.

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GENERAL PUMP

2.1.1 Dismantling the Mechanical Parts

The correct sequence is the following:

Completely drain the oil of oil, as indicated in 2.1.

Remove the valve lifters from the head and the head from the pump casing as shown in 2.2.1 (from fig. 103 to
fig. 105).

Detach the upper inspection cover and the lower inspection cover by unscrewing the 4 attachment screws,
as shown in point 2.2.3 (fig. 129 and fig. 140). Slip off the O-rings and replace them if necessary.

Remove the three plungers and the liner/gasket support assemblies, as shown in 2.2.3 (fig. 138, fig. 141 and
fig. 142).

Remove the three spray guard spacer rings and the spray guards, as shown in 2.2.3 (fig. 143 and fig. 144)

Unscrew the M6 locking grub screws from the three oil seal covers (pos.1, fig.2).

A member of the Interpump Group

LK SERIES

Screw in a threaded bar or an extractor M6 screw in the holes in the oil seal covers (pos. 1, fig.3) and
remove the covers from the pump assembly (pos. 1, fig. 4).

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GENERAL PUMP

Take out the radial seal ring, (pos. 1, fig. 5) and the outside O-ring (pos.1, fig 6).

Remove the lug from the PTO shaft (pos. 1, fig. 7)

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LK SERIES

Unscrew the attachment screws from the shaft end cover (pos. 1, fig. 8) and slip the cover off the PTO shaft.

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GENERAL PUMP

Unscrew the crankcase cover attachment screws (pos. 1, fig. 9) and remove it. Slip off the O-ring and replace
it if necessary.

Now remove the two bearing covers by unscrewing the screws (pos. 1, fig10). To help with their removal, use
2 M8 grub screws or screws (pos. 1, fig 11) as extractors. Slip off the O-ring and replace if necessary.

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LK SERIES

Insert a shim under the shank of the central connecting rod, to stop the rotation of the crankshaft
(pos. 1, fig. 12).

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GENERAL PUMP

Unscrew and take out the bushing locking flange attachment screws, from both sides (pos. 1, fig. 13). The
bushing locking flanges must be left in position (pos. 1, fig. 14).

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LK SERIES

On one side, screw a ferrule (type SKF KM20) onto the pressure bushing (pos. 1, fig. 15), and then unblock
the bushing using a striking hammer (pos. 1, fig 16), but do not remove it. Repeat the operation on the other
side.

Remove the shim from under the shank of the central connecting rod.

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GENERAL PUMP

Unscrew the connecting rod screws (pos.1, fig. 17).

Dismantle the small ends of the connecting rods with the half-bearings. During the operation take particular
care to note the order in which the parts are removed

The connecting rod small ends and the big end halves must be reassembled in exactly the
same order and pairings in which they were dismantled.

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LK SERIES

To prevent any errors, small ends and big end halves are numbered on one side (pos. 1, fig. 18).

Advance the three big end halves as far as possible in the direction of the head. Slip off the three upper half­bearings of the beg end halves (pos. 1, fig 19).

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GENERAL PUMP

Take out both of the pressure bushings (pos. 1, fig. 20).

Separate the bushing locking flange from the pressure bushing (pos. 1, fig. 21).

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LK SERIES

Unscrew the screws of the two bearing support covers (pos. 1, fig. 22).

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GENERAL PUMP

Apply an M16 threaded pin to one end of the crankshaft (pos. 1, fig. 23) and, while keeping it raised, take out
the bearing support cover complete with bearing and O-ring (pos. 1, fig. 24). To help with their removal, use 2
M10 grub screws or screws (pos. 2, fig. 23) as extractors. Repeat the operation on the other side

Lay the crankshaft on the bottom of the crankcase. Separate the bearing support cover from the bearing,
using a striking hammer (pos. 1, fig. 25).

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LK SERIES

Unscrew the attachment screws of the left and right PTO bearing cover (pos. 1, fig. 26) and slip the two cov­ers off the PTO shaft. To help with their removal, use 3 M8 grub screws or screws (pos. 1, fig. 27) as
extractors.

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GENERAL PUMP

Take out the radial seal ring (pos. 1, fig. 28) and the outside O-ring (pos. 1, fig. 29) and the lubrication hole
O-ring (pos. 1, fig. 30)

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LK SERIES

Roll back the three connecting rods as far as possible (until they touch the crankshaft). Using a striking
hammer or mallet (pos. 1, fig. 31), take out the PTO crankshaft from either one of the two sides
(pos. 1, fig. 32).

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GENERAL PUMP

Slip the internal bearing rings off the PTO shaft (pos. 1, fig. 33) and also slip off the two internal bearing
spacers (pos. 2, fig. 33).

The internal and external bearing rings must be reassembled in exactly the same order
and pairings in which they were dismantled.

A member of the Interpump Group

LK SERIES

Using a sufficiently long bar (pos. 1, fig. 34) and a striking hammer, take the bearing rings out of the pump
casing (pos. 1, fig. 35), along with the external spacer (pos. 1, fig. 36) and the bearing lubrication bushing
(pos. 1, fig. 37).

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GENERAL PUMP

Advance the big end halves in the direction of the hydraulic part and lock them in place using the special
tool (p/n F27566200) (pos. 1, fig. 38).

Move the crankshaft from the lower part of the casing (pos. 1, fig. 39).

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LK SERIES

Proceed to unscrew the screws of the device (p/n) F2756620) to unlock the connecting rods (pos. 1, fig. 40)
and then take out the connecting rod/piston head assemblies from the rear opening of the casing (pos. 1, fig.

41).

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GENERAL PUMP

Couple the big end halves to the small ends that were previously dismantled, with reference to their
numbering scheme (pos. 1, fig. 42).

Remove the two pin-locking Seeger rings using the correct tool (pos. 1, fig. 43).

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LK SERIES

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GENERAL PUMP

Slip out the pin (pos. 1, fig 44) and take out the connecting rod (pos. 1, fig. 45).

To separate the stem from the piston head, it is necessary to unscrew the hexagonal-head M10 screw using
a no. 17 socket wrench (pos. 1, fig. 46).

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LK SERIES

Complete the disassembly of the mechanical parts by removing the oil level lights and the eyebolts.

2.1.2 Assembling the Mechanical Parts
Proceed with the assembly, following the reverse of the procedure shown in 2.2.1/ The correct sequence is as
follows:

Attach the two oil level lights and the two oil drain plugs (pos. 1 and 2, fig. 47).

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