Rebuilding a Bosch 11316EVS Demolition hammer

Everything is straightforward except replacing the balls in the chuck, so I left the chuck with a local rental place to do that.

You basically need:

Phillips screwdriver
Allen wrench set
10 mm hex socket drive
Torque wrench
Soft wire (found in hardware store near picture framing stuff)
Needle nose pliers
Larger flat blade screwdriver (1/4%u201D tip)
Small screwdriver and/or dental probe (remove O rings)
VSR drill
Small drill bit
Internal snap ring pliers (chuck)
Drift (chuck)
Very small sheet metal screws (chuck)

Personal protective equipment
Paper towels
Vinyl gloves

You can take off screws #27 and set aside the chuck
You can remove #41 through #29 on the diagram
#35, guide tube. You can remove a little later when you can position the piston #56

The power switch must be removed and installed in the off position.
You must pry it from the bottom of the switch.

Remove 2 x #136 screws and 4 x #140 screws. The former are machine screws.

Now is a good time to do the brushes one at a time.
Remove the fast on clip on the brush,
Use a pair of needle nose pliers and lift the brush spring. Place the soft wire under the brush spring. Use it to lift the brush clip and insert the new brush. Attach the Faston connector.

Remove 4 x #127 screws (Impact housing assembly)

Remove 4 X 125 screws. (motor housing)

Remove #115 with a 10 mm hex wrench.

Remove 4 x #129 screws and remove the impact housing assembly.


Observe the piston and move the motor at the base such that the connecting rod is at the back of the drill. This will make it easier to remove item #35. Remove item #35.
Once #35 is removed, you can remove the piston. I forget if it needs to be far forward or far back.

The Eccentric Gear #72 will drop out.

Now it basically simple to clean up all the parts, reassemble and regrease. Don't forget to grease the O-rings prior to assembly.

Everything is straightforward EXCEPT the connecting rod #70 and especially #35, the inner piston cylinder.

Once #72 is back in place and the stub positioned to either the (front or rear?) of the hammer, the piston can be inserted and the connecting rod attached.

The piston must be totally retracted in order to put back #35. It's much easier to do in this position.

The switch plate #77 and #112, threaded ring, are other potential issues.

#112 has a notch and only assembles one way. The torque specs are located in the rebuild kit. I wouldn't torque this until everything is assembled.

Insert the switch at an angle from the top with the switch underneath in the OFF position.

Now, you basically have everything assembled up to #41, the upper housing minis item #41.

I then inserted two of the #27 screws and placed a piece of soft wire to hold everything in place and set it aside.

Now, it's time to deal with the chuck. The dust shield, #21 is surprisingly easy to remove. Insert a screwdriver in the middle and pry. I learned that later.

#18 can be removed with snap ring pliers. Remove the spring around the seal and cut the seal to see what your doing. What you want to do is drill a hole at an angle into the seal. The hole should be just big enough to start the sheet metal screw. It's nearly impossible to drill the hardened housing. The holes should be 180 degrees apart. When you insert the screw the seal will unseat. Note, that it's installed what you might think is backwards.

#138, ring can be removed with a small screwdriver.

As I said the tough part seems to be removing #143, the spring ring. I punted.
It does seem that you need to compress #31, bushing, by item #144 washer.

It seems to take a bit of force to compress the bushing and I didn't feel like trying to build a press.