Hitachi h65sb jackhammer motor works but doesnt hammer.

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: I have a old electric 120vac jackhammer (not sure manf.)

usally their is grease packed in the hammer part,you can usally see a plastic type bung(plug)on outter casing

SOURCE: how to fix jackhammer it doesnt hammer.

Bosch hammer drill 11304 uses sds bits and is generally a good hammer. Usually only needs yearly (depending on use) lube with Bosch grease to keep it working well. No hammering usually means lack of lubrication or broken connecting rod on the hammer piston. Not easy to repair. Tackle only if you have lots of experience with Bosch or other complicated hammers. Parts are easy to find. Good luck.