Question about Bosch 11236VS Rotary Hammer

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Tool bogs down while drilling holes in concrete-as though it's binding up inside.

Tool bogged down and I may have smelled a slight burning smell. What parts would I need to fix this problem, and how easy is it to fix?

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Depends what damage has been done to the motor. If the tool is still running but sparking you need to check what sort of sparks they are. Short fat blue sparks only going halfway round the commutator (brush end of motor/armature) then it is 90% probable that just your field coil assy is blown. If it is thinner, whitersparks going all the way around then it is the armature and possibly the field aswell. Another way to check is to remove the brushes via the covers on either side at teh bottom of the motor and check the contacting surface. If it is fairly shiney and polishe then there is little sparking and hopefully no cause for concern. If one or both is pitted and dull it has been sparking and burning. If one is shorter and darker than teh otehr this indicates a problem with the field coil. It isn't a massivly hard job to change the motor parts. If you need more advice let me know.

Posted on Oct 25, 2008

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I order parts for my Bosch tools at They have the parts lists also so it is easy to find what you need. Don't forget to order some bosch grease for your tool because you will need to carefully wash-out all the old grease with metal bits. Good luck with you repair. Enjoy

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