Bosch Rexroth SM 12 Operating instructions

Repair Manual
RE 64122-S/06.2011
English
Mobile control block, 6-way version
sandwich plate design
SM 12

The data specified above only serve to describe
the product. No statements concerning a certain
condition or suitability for a certain application
can be derived from our information. The
information given does not release the user from
the obligation of own judgment and verification.
It must be remembered that our products are
subject to a natural process of wear and aging.
© This document, as well as the data,
specifications and other information set forth in it,
are the exclusive property of Bosch Rexroth AG.
It may not be reproduced or given to third parties
without its consent.
The title page shows an illustration of an example
configuration. The delivered product may
therefore deviate from the illustration.
The original operating instructions were written in
French.
Subject to revision.

Contents
1 Introduction......................................................................................... 4
2 Safety instructions ............................................................................. 5
2.1 General safety instructions ............................................................ 5
2.2 Safety instructions in this document .............................................. 5
3 Troubleshooting ................................................................................. 6
4 Fundamental rules.............................................................................. 8
4.1 General information concerning control block connection ............. 8
5 Removal / installation of the SM 12 control block ........................... 8
5.1 General recommendations............................................................. 8
5.2 Removal of the SM 12 control block .............................................. 9
5.3 Installation of the SM 12 control block ........................................... 9
5.4 Starting, maximal pressure set up ................................................. 9
6 Inlet and outlet elements repair procedure .................................... 10
6.1 Primary pressure relief valve replacement................................... 10
6.2 Removal of the outlet element type K cartridge ........................... 11
6.3 Removal of the outlet element type KW adjustable flow control .. 12
6.4 Removal of the outlet element type KV check valve.................... 13
6.5 Removal of the Externe pilot oil supply block X ........................... 14
6.6 Removal of the Interne pilot oil supply block Y ............................ 15
7 Distribution element repair procedure ........................................... 16
7.1 Secondary valves replacement.................................................... 16
7.2 Removal of a spool return via a spring operation A2 Z1 or A2 G11 8
7.3 Spool stroke measurement (3 position) ....................................... 21
7.4 Removal of a mechanical detent system B2, C2, D2 or E2 ......... 22
7.5 Removal of a manual operation M1 ............................................. 25
7.6 Removal of a manual operation with encapsulated lever R5....... 26
7.7 Removal of a hydraulic operation H200 or H400 ......................... 27
7.8 Removal of a electro-hydraulic operation W200 .......................... 28
7.9 Removal of a check-valve............................................................ 29
8 Control block Disassembly / Assembly.......................................... 30
RE 64122-S/06.2011 | Type SM 12 Bosch Rexroth AG 3/30

Introduction1
This manual deals with the instructions relative to servicing and
maintenance operations for the SM 12 control blocks. For the inspections
and servicing operations associated with the hydraulic system of the
machine to which the block is connected, please consult the maintenance
manual supplied by the equipment manufacturer.
It is recommended that only qualified personnel perform the installation,
connection and maintenance of this device, and that all operations be
carried out in compliance with the technical standards in force and the
cleanliness regulations specific to this type of installation.
To ensure maximum performance and safety during maintenance
operations we advise you to READ THIS MANUAL THOROUGHLY.
All information, illustrations, instructions and characteristics contained in
this document are based on the latest product information available at
the time of publication. In its attempts to maintain a high-quality product,
BOSCH REXROTH reserves the right to make design or technical
modifications at any time and without prior notification.
Related documents
SM 12 is a system component.
Also follow the instructions for the other system components.•
Also follow the instructions in the following manuals:•
System documentation from the system manufacturer–
Service instruction manual RE64025–
Datasheet RE64122–
Spare parts manual RDEF64122-E–
4/30 Bosch Rexroth AG Type SM 12 | RE 64122-S/06.2011
Introduction

Safety instructions2
General safety instructions2.1
See service instruction manual RE64025.
Safety instructions in this document2.2
In this manual, there are safety instructions before the steps whenever
there is a danger of personal injury or damage to the equipment. The
measures described to avoid these hazards must be observed.
Safety instructions are set out as follows :
Signal words/warning signsTableau 1:
Signal word/
warning sign
Application
DANGER
Indicates an imminently hazardous
situation which, if not avoided, will
certainly result in serious injury.
WARNING
Indicates a potentially hazardous
situation which, if not avoided, could
result in serious injury.
NOTICE Indicates property or environment
damages, practices not related to
personal injury.
CAUTION Indicates a delicate operation.
Use or application hints.
DANGER
Type of risk!
Description
precautionsf
RE 64122-S/06.2011 | Type SM 12 Bosch Rexroth AG 5/30
Safety instructions

Troubleshooting3
CAUTION
BEFORE STARTING ANY PROCEDURES OF TROUBLE SHOOTING OR REMOVING THE CONTROL BLOCK,
INSPECT THE GLOBAL MACHINE’S HYDRAULIC SYSTEM TO ELIMINATE ALL POSSIBLE MALFUNCTIONS NOT
RELATED TO THE SM 12 CONTROL BLOCK.
Abnormal operation of the actuators connected to the control blockTableau 2:
Malfunction Probable cause Additional Checks Remedy
Lack of strength at all
actuators
1 - Primary pressure relief valve
defective
Take a pressure measurement
(see block specifications)
Replace primary pressure relief valve
(see § 6.1)
2 - Primary pressure relief valve
out of adjustment
Make necessary adjustments
(see § 5.4)
Lack of force on one
actuator only
1 - Secondary pressure relief
valve out of adjustment
Reset to original pressure (refer to
block specifications).
2 - Secondary pressure relief
valve blocked "open"
(return to tank)
Replace secondary pressure relief
valve (see § 7.1)
Movement performance
slow
Spool stroke incorrect Manual control: measure spool
stroke (see § 7.3)
If stroke is incorrect: replace the
distribution element (see § 8)
Lack of load hold at work Load hold check valve failure Replace check valve or distribution
element (see § 8 and 7.9)
Lack of load hold at
neutral position or relief
valve internal leak
Excessive clearance between the
housing and the spool or relief
valve internal leak
Replace the distribution element (see
§ 8) or secondary pressure relief
valve (see § 7.1)
Abnormal control block operationTableau 3:
Malfunction Probable cause Additional Checks Remedy
Detent malfunction Mechanism defective Replace mechanical detent
(see § 7.4)
Defective manual
operation type R5: no
movement
Ball joint broken Replace the operation (cf. § 7.6)
Defective manual
operation type M1 : lever
stiff
1 - Nut overtightened Adjust tightening torque (cf. § 7.5)
2 - System defective Replace the operation (cf. § 7.5)
Increase of force on
controls or spool return
defective
Control block assembly tie rods
too tight
Check tightening torque Loosen and tighten
to 18 ± 10% N.m.
CAUTION
REMOVE CONTROL BLOCK
FROM ITS FIXATION POINTS
Spool seals obsolete Replace spool seals (see § 7.2)
6/30 Bosch Rexroth AG Type SM 12 | RE 64122-S/06.2011
Troubleshooting

Visual defectsTableau 4:
Malfunction Probable cause Additional Checks Remedy
Spool leaking oil Spool seals defective Replace spool seals (see § 7.2)
Check the rubber boot condition
Oil leakage at pressure
relief valves and plugs
Seals defective Remove pressure relief valve or plug
and replace seals (see § 7.1)
Oil leakage between
elements
Seals between elements defective Remove working sections and
replace seals (see § 8)
Control block assembly tie rods
not enough tight
Check tightening torque Tight to 18 ± 10% N.m.
CAUTION
REMOVE CONTROL BLOCK
FROM ITS FIXATION POINTS
Oil leaking from hydraulic
operator housing
Seal between housing and body
defective
Replace seal (see § 7.7)
R5 manual operation boot
damaged
Replace boot (cf. § 7.6)
RE 64122-S/06.2011 | Type SM 12 Bosch Rexroth AG 7/30
Troubleshooting

Fundamental rules4
General information concerning control block4.1
connection
When removing the block, all openings must be plugged immediately to
prevent any contamination of the hydraulic system.
When replacing the block, remove the plastic plugs from the openings and
lines just before making the connections.
Do not tighten connectors to a torque greater than that specified in the
assembly instructions.
Check the hydraulic installation’s oil quality and filtration capacity during all
servicing/maintenance operations.
The use of Teflon tape, hemp and joint filler is prohibited.
Hydraulic lines and connections must not be under any strain whatsoever.
Removal / installation of the SM 125
control block
General recommendations5.1
NOTICE
Property damages risk
BEFORE REMOVING THE SM 12 CONTROL BLOCK FROMf
THE MACHINE, THE BLOCK AND ITS SURROUNDINGS MUST
BE THOROUGHLY CLEANED (DO NOT DIRECT THE JET OF A
PRESSURE WASHING UNIT DIRECTLY AT THE UNIT).
NO IMPURITIES MUST ENTER THE HYDRAULIC SYSTEM.f
PLASTIC PLUGS ARE TO BE FITTED ON LINES AND ORIFICES
IMMEDIATELY FOLLOWING THEIR REMOVAL.
DANGER
Wear protective clothing and use suitable equipment to preventf
accidents, particularly concerning the hydraulic fluid.
Use the lifting eyes and suitable handling equipment.f
Set all actuators connected to the machine in neutral position (on thef
ground, at lower limit ...) to avoid accidents which could result from
uncontrolled movements of the equipment when the hydraulic system
is disconnected.
With the machine off, release the pressure remaining in the systemf
by manipulating all of the distribution spools. This is performed by
moving the handle in all directions.
8/30 Bosch Rexroth AG Type SM 12 | RE 64122-S/06.2011
Fundamental rules

Removal of the SM 12 control block5.2
Install a vacuum pump on the tank to limit oil leakage whenf
connections are removed.
After disconnecting the lines from the block, immediately fit the sealingf
plugs. Make sure to collect any possible oil leakage in a suitable
receptacle.
Unscrew the mounting screws and remove the control block.f
Installation of the SM 12 control block5.3
Contact faces must be perfectly clean.f
Check the evenness of support area on the machine (Tolerance:f
0.5 mm).
Check the condition of line connector seals.f
Clean the block if it has been in storage for a long period of time.f
Correctly place and secure the control block onto the machine with thef
mounting screws.
Connect the lines to the block as per the connecting diagram andf
tighten to the torque specification (refer to the table in the Data sheet).
Ensure that hoses are not twisted or rub.f
Once correctly installed, the unit can be placed into operation.
Starting, maximal pressure set up5.4
Decalibrate the primary pressure relief valve (17 mm open end spannerf
on counternut) before starting the machine,
Maintain one of the control block spool valve in action before the linkedf
hydraulic receiver is at the end of stroke.
On the spool valve, the value of the secondary valve pressure must be
greater than that of the primary pressure relief valve to adjust.
Adjust the maximum pressure measured in M using the primaryf
pressure relief valve (6 mm socket wrench).
Tighten the counternut of the adjusting screw to the torque:f
20 ± 10% N.m.
RE 64122-S/06.2011 | Type SM 12 Bosch Rexroth AG 9/30
Removal / installation of the SM 12 control block

Inlet and outlet elements repair6
procedure
6.1 Primary pressure relief valve replacement
On the inlet element, unscrew the primary pressure relief valve (24 mm
open end spanner).
Reassembly:
install the primary pressure relief valve on the inlet element, torque:1.
45 ± 10% N.m.
set the primary pressure relief valve to the specified value (see § 5.4),2.
fit a new appropriate locking cover.3.


 
The control block does not need to be removed from the machine to
perform this operation.
DANGER
Oil pressure
Machine off:
place all of the machine’s actuators connected to the control block inf
neutral position,
release stored pressure by operating all the spools.f
NOTICE
Environment damages risk
Install a vacuum pump on the tank to limit oil leakage during thisf
operation.
Collect possible leaks with a suitable receptacle.f
10/30 Bosch Rexroth AG Type SM 12 | RE 64122-S/06.2011
Inlet and outlet elements repair procedure

Removal of the outlet element type K cartridge6.2
On the outlet element, unscrew the cartridge (32 mm open end spanner).
Reassembly:
replace the o-ring and the back-up ring of the cartridge,1.
blow Loctite residues in the orifice and on the cartridge thread,2.
apply a droplet of Loctite 577 oiltight on two to three threads of the3.
cartridge,
torque for the cartridge : 150 ± 10% N.m.4.
CAUTION
WAIT FOR 8 HOURS BEFORE USING THE MACHINE TO LET THE
LOCTITE 577 DRY COMPLETELY.
�
The control block does not need to be removed from the machine to
perform this operation.
DANGER
Oil pressure
Machine off:
place all of the machine’s actuators connected to the control block inf
neutral position,
release stored pressure by operating all the spools.f
NOTICE
Environment damages risk
Install a vacuum pump on the tank to limit oil leakage during thisf
operation.
Collect possible leaks with a suitable receptacle.f
RE 64122-S/06.2011 | Type SM 12 Bosch Rexroth AG 11/30
Inlet and outlet elements repair procedure

Removal of the outlet element type KW6.3
adjustable flow control
Cartridge removal
On the outlet element, unscrew the cartridge (27 mm open end spanner).
Reassembly:
replace the throttle o-ring and thrust ring,1.
replace the cartridge o-ring,2.
mount the cartridge inside the outlet element, torque for the cartridge :3.
70 ± 10% N.m.
Flow setting
Loosen the locking nut (18 mm open end spanner).
Calibrate the flow unscrewing in reverse direction the throttle (6 mm socket
wrench).
Torque for the locking nut : 50 ± 10% N.m.







The control block does not need to be removed from the machine to
perform this operation.
DANGER
Oil pressure
Machine off:
place all of the machine’s actuators connected to the control block inf
neutral position,
release stored pressure by operating all the spools.f
NOTICE
Environment damages risk
Install a vacuum pump on the tank to limit oil leakage during thisf
operation.
Collect possible leaks with a suitable receptacle.f
12/30 Bosch Rexroth AG Type SM 12 | RE 64122-S/06.2011
Inlet and outlet elements repair procedure

Removal of the outlet element type KV check6.4
valve
Outlet check valve removal
On the outlet element, unscrew the check valve (24 mm open end
spanner).
Reassembly :
replace the check valve o-ring and back-up ring,1.
mount the check valve inside the outlet element, torque for the valve :2.
150 ± 10% N.m.
Outlet check valve setting
Loosen the locking nut (19 mm open end spanner).
Unscrew the throttle (6 mm socket wrench).
replace the throttle o-ring,1.
mount the throttle inside the check valve and set it to the specified2.
value,
t3. orque for the locking nut : 50 ± 10% N.m.








The control block does not need to be removed from the machine to
perform this operation.
DANGER
Oil pressure
Machine off:
place all of the machine’s actuators connected to the control block inf
neutral position,
release stored pressure by operating all the spools.f
NOTICE
Environment damages risk
Install a vacuum pump on the tank to limit oil leakage during thisf
operation.
Collect possible leaks with a suitable receptacle.f
RE 64122-S/06.2011 | Type SM 12 Bosch Rexroth AG 13/30
Inlet and outlet elements repair procedure

Removal of the Externe pilot oil supply block X6.5
On the inter-connecting located underside the outlet element, unscrew the
4 mounting screws (4 mm socket wrench).
Remove:
the plate•
the 2 o-rings.•
Reassembly:
replace the 2 o-rings,1.
reassemble parts in reverse order,2.
torque for the 4 mounting screws: 6 ± 10% N.m.3.
�
The control block does not need to be removed from the machine to
perform this operation.
DANGER
Oil pressure
Machine off:
place all of the machine’s actuators connected to the control block inf
neutral position,
release stored pressure by operating all the spools.f
NOTICE
Environment damages risk
Install a vacuum pump on the tank to limit oil leakage during thisf
operation.
Collect possible leaks with a suitable receptacle.f
14/30 Bosch Rexroth AG Type SM 12 | RE 64122-S/06.2011
Inlet and outlet elements repair procedure

Removal of the Interne pilot oil supply block Y6.6
Block remplacement
On the plate adjacent to the inlet element, unscrew the 4 mounting screws
(6 mm socket wrench).
Remove:
the block•
the 4 o-rings.•
Reassembly:
replace the block and the 4 o-rings,1.
reassemble parts in reverse order,2.
torque for the 4 mounting screws: 18 ± 10% N.m.3.
�
The control block does not need to be removed from the machine to
perform this operation.
DANGER
Oil pressure
Machine off:
place all of the machine’s actuators connected to the control block inf
neutral position,
release stored pressure by operating all the spools.f
NOTICE
Environment damages risk
Install a vacuum pump on the tank to limit oil leakage during thisf
operation.
Collect possible leaks with a suitable receptacle.f
RE 64122-S/06.2011 | Type SM 12 Bosch Rexroth AG 15/30
Inlet and outlet elements repair procedure

Distribution element repair7
procedure
Secondary valves replacement7.1
Relief valve A, B, H or anti-cavitation check valve E
On the distribution element in question, unscrew the secondary valve
(24 mm open end spanner).
Replace the 3 seals or replace the pressure relief valve.
Reassembly:
if necessary, set the pressure relief valve to the specified value,1.
install the secondary pressure relief valve on the distribution element,2.
torque for the secondary valve: 70 ± 10% N.m.3.
relief valve: fit a new appropriate locking cover.4.
The control block does not need to be removed from the machine to
perform this operation.
DANGER
Oil pressure
Machine off:
place all of the machine’s actuators connected to the control block inf
neutral position,
release stored pressure by operating all the spools.f
NOTICE
Environment damages risk
Install a vacuum pump on the tank to limit oil leakage during thisf
operation.
Collect possible leaks with a suitable receptacle.f
16/30 Bosch Rexroth AG Type SM 12 | RE 64122-S/06.2011
Distribution element repair procedure

Plug Q
On the distribution element in question, unscrew the plug (6 mm socket
wrench).
Replace the 3 seals or replace the plug.
Reassembly : torque : 70 ± 10% N.m.f
RE 64122-S/06.2011 | Type SM 12 Bosch Rexroth AG 17/30
Distribution element repair procedure

Removal of a spool return via a spring7.2
operation A2 Z1 or A2 G1
Tongue Z1 or fork G1 side
On the distribution element in question, unscrew the mounting screws on
the plate (4 mm socket wrench).
Remove:
mounting screws (L=8 mm) (tongue : 4 screws ; fork : 2 screws),•
the plate,•
the o-ring and the wiper ring.•
Reassembly:
replace the o-ring and the wiper ring,1.
CAUTION
POSITION THE LIP PART OF THE WIPER RING ON THE OUTSIDE.
reassemble parts in reverse order,2.
torque for mounting screws: 5 ± 10% N.m.3.


The control block does not need to be removed from the machine to
perform this operation.
DANGER
Oil pressure
Machine off:
place all of the machine’s actuators connected to the control block inf
neutral position,
release stored pressure by operating all the spools.f
NOTICE
Environment damages risk
Install a vacuum pump on the tank to limit oil leakage during thisf
operation.
Collect possible leaks with a suitable receptacle.f
18/30 Bosch Rexroth AG Type SM 12 | RE 64122-S/06.2011
Distribution element repair procedure









Cover side A2
On the distribution element in question, unscrew the 2 mounting screws on
the cover (L = 10 mm) (4 mm socket wrench).
Remove the cover.
Remove the spool from the working section.
Use the spool clamp (Rexroth-Ref. R9 08 103 001) and a vuce to
secure the spool.
CAUTION
IN ORDER TO AVOID DAMAGING THE SPOOL, PLACE IT
APPROXIMATELY 30 MM FROM THE END OF THE SPOOL (NEVER IN
THE CENTRE).
Beforehand, heat the spool to 200° C in an oven or, failing that, with a
heat gun. Do not use fire.
WARNING
Hot spool!
Danger of burns
Wear thick protective gloves when handling the hot spool.f
Remove the adapter (5 mm socket wrench).
Remove:
2 spring retainers,•
the spring,•
the plate,•
the o-ring and the wiper ring.•
RE 64122-S/06.2011 | Type SM 12 Bosch Rexroth AG 19/30
Distribution element repair procedure

Reassembly:
replace the o-ring and the wiper ring,1.
CAUTION
SEALS MUST BE FITTED ON THE END OF THE SPOOL SO THAT
THEY ARE NOT DAMAGED ON THE SPOOL GROOVES AND THEIR
TIGHTNESS PROPERTY DOES NOT DETERIORATE.
POSITION THE LIP PART OF THE WIPER RING ON THE OUTSIDE.
reassemble parts in reverse order,2.
grease the spring,3.
except of coating, apply a droplet of loctite 262 on the end of the spool4.
internal thread,
torque for the adapter: 10 ± 10% N.m,5.
mount the spool inside the distribution element,6.
torque for the 2 cover screws: 5 ± 10% N.m7.
CAUTION
WAIT FOR 8 HOURS BEFORE USING THE MACHINE TO LET THE
LOCTITE 262 DRY COMPLETELY.
20/30 Bosch Rexroth AG Type SM 12 | RE 64122-S/06.2011
Distribution element repair procedure