Practical Advice; Maintenance And Service; Maintenance And Cleaning; After-Sales Service And Application Service - Bosch GBH 12-52 D Professional Manual Original

– To switch off the power tool, push the on/off switch (6)
back down (0) and release it.
For low temperatures, the power tool reaches the full ham-
mer/impact capacity only after a certain time.
Changing the chiselling position (Vario-Lock)
You can lock the chisel in 16 different positions, allowing
you to select the optimum working position for each task.
– Insert the chisel into the tool holder.
– Turn the mode selector switch (3) to the "drilling" posi-
tion.
– Turn the application tool to the required chisel position.
– Turn the mode selector switch (3) to the "chiselling" posi-
tion. With this, the tool holder is locked.
Adjusting the Speed/Impact Rate
The electronic control enables continuous speed and impact
rate preselection for material-specific adjustments.
– Select the impact rate with the thumbwheel (7) according
to the material.
The information in the table below describes the recommen-
ded values.
Application
Working on plaster/light building materials
Removing tiles
Working on brick
Working on concrete

Practical Advice

Overload clutch
If the application tool jams or snags, the power trans-
u
mission to the drill spindle will be interrupted. Always
hold the power tool firmly with both hands to with-
stand the forces this may create and adopt a position
with stable footing.
Switch the power tool off immediately and remove the
u
application tool if the power tool becomes blocked.
Switching on when the drilling tool is blocked may
cause high torque reactions.
Vibration damping
GBH 12-52 DV
The integrated vibration damping function re-
duces the generated vibration.
Do not continue to use the power tool if the damping
u
element is damaged.
Sharpening Chisels
Only sharp chiselling tools will produce good results, there-
fore sharpen your chiselling tools in good time before use.
This will ensure a long service life for the tools and good
work results.
Re-sharpening
Grind chiselling tools against sanding discs, e.g. aluminium
oxide, under a steady stream of water. Make sure that the
Bosch Power Tools
cutting edges show no annealing colours; this will impair the
hardness of the chiselling tools.
To forge a chisel, heat it to 850–1050 °C (pale red to yel-
low).
To harden a chisel, heat it to approx. 900 °C and quench in
oil. Then, leave it in an oven for approx. one hour at 320 °C
(annealing colour: pale blue).

Maintenance and Service

Maintenance and Cleaning

Pull the plug out of the socket before carrying out any
u
work on the power tool.
To ensure safe and efficient operation, always keep
u
the power tool and the ventilation slots clean.
In order to avoid safety hazards, if the power supply cord
needs to be replaced, this must be done by Bosch or by an
after-sales service centre that is authorised to repair Bosch
power tools.
Replace a damaged dust protection cap immediately.
u
It is recommended that you have use an after-sales
service for this.
Thumbwheel
position
– Clean the tool holder after each use.
1
Service indicator
When the carbon brushes are worn out, the power tool
switches itself off. This is indicated approx. 8 hours before-
hand by the service indicator (8) lighting up or flickering.
6
The power tool must be sent to customer service for main-
tenance. For addresses, see: (see "After-Sales Service and
Application Service", page 15)

After-Sales Service and Application Service

Our after-sales service responds to your questions concern-
ing maintenance and repair of your product as well as spare
parts. You can find explosion drawings and information on
spare parts at: www.bosch-pt.com
The Bosch product use advice team will be happy to help you
with any questions about our products and their accessor-
ies.
In all correspondence and spare parts orders, please always
include the 10‑digit article number given on the nameplate
of the product.
Great Britain
Robert Bosch Ltd. (B.S.C.)
P.O. Box 98
Broadwater Park
North Orbital Road
Denham Uxbridge
UB 9 5HJ
At www.bosch-pt.co.uk you can order spare parts or arrange
the collection of a product in need of servicing or repair.
Tel. Service: (0344) 7360109
E-Mail: boschservicecentre@bosch.com
You can find further service addresses at:
www.bosch-pt.com/serviceaddresses
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