My brute jackhammer works sometimes if i bang it around

SOURCE: I have a Bosch brute jackhammer, I need the tool

You can use an adjustable face spanner wrench to remove that cap. I don't remember the pin size but you can measure the holes and get the appropriate size. You can remove the whole plate with the armature by undoing the 4 cap screws. Prior to removing the motor plate you have to remove the handle plate from the axle that goes through the body. Undo the nut that holds the assembly on and slide it off. You can now remove the Armature plate. After removing the cap screws pull the assembly out about 1-2 inches. You will see the wires that go to the field attached to the brush holders. Remove the screw that holds these wires to the brush holders. You can then safely remove the whole assembly. This also makes it easier to remove that cap plug with the spanner wrench, because you can now put the whole assembly in a vise. I always heat around the cap with a torch before doing anything. Then I tap on the plug with a hammer a couple of times and voila it turns alot easier. Corrosion almost always builds up on this cap because of the different metals. (Steel and Aluminum respectfully)

Your hammer may have a broken connecting rod. To inspect this make sure you ping the cylider and body with marks so you line them up the same way. Then remove the 4 cap bolts that hold the cylinder to the body. Remove the cylinder and inspect the hammer cylinder and rod. If the connecting rod is not broken you will have to inspect the gears and pinions to make sure they are ok.

SOURCE: switch schematic for a busch brute jackhammer

Go to www.boschtoolsservice.com

SOURCE: my jackhammer will not run, the cord and switch are good

Check your brushes. The brushes on the Brute breaker have a spring loaded, non-conductive pin in them. When either brush wears down far enough the pin pops out and prevents damage to the expensive armature. If by chance the brushes are OK you may have to have your armature tested.