PXXX-3 Ed 1
3
The twin hammers will be free to slide from
the Hammer Frame when the Hammer Pins
are removed. Do not drop the Hammers.
4. With the Anvil removed, lift out the two
Hammer Pins.
5. Remove the Hammers.
Disassembly of the Reverse Valve
1. Unscrew the Reverse Valve Knob Screw (16)
and remove the Reverse Valve Knob (15).
This Screw is installed with a thread locking
compound. You may have to heat it slightly
to loosen the Screw.
2. While slowly rotating the Reverse Valve
(12), withdraw it from the Reverse Valve
Bushing (3).
Be careful you do not lose the Reverse Valve
Detent Ball (13) and Spring (14) from the
hole in the side of the Reverse Valve.
Disassembly of the Motor
1. Lift the Rear Hammer Frame Washer (36) and
the two Motor Clamp Washers (33) from the
front of the motor.
2. Grasp the splined end of the Rotor (22) and
pull the assembled motor from the Motor
Housing (1).
3. Lift the Front End Plate (30) and Front Rotor
Bearing (24) from the splined end of the
Rotor.
4. Remove the Cylinder (26) and Vanes (29).
5. Remove the Rear Rotor Bearing Retainer
(25).
6. Lift the Rear End Plate (31) and Rear Rotor
Bearing (23) from the Rotor.
Disassembly of the Throttle
Mechanism
1. Unscrew the Air Strainer (9) and remove it.
2. Withdraw the Throttle Valve Spring (7),
Throttle Valve (5), and Throttle Valve Stem
(8). Remove the Throttle Valve Face (6) from
the Throttle Valve.
3. 3. Remove the Trigger Pin (11) and Trigger
(10).
Assembly
General Instructions
1. Always press on the inner ring of a ball-type
bearing when installing the bearing on a
shaft.
2. Always press on the outer ring of a ball-type
bearing when pressing the bearing into a
bearing recess.
3. Whenever grasping a tool or part in a vise,
always use leather-covered or copper-
covered vise jaws. Take extra care with
threaded parts or housings.
4. Always clean every part and wipe every part
with a thin film of oil before installation.
5. Apply a film of O-ring lubricant to all O-
rings before final assembly.
Assembly of the Throttle
Mechanism
1. Place the Trigger (10) in the Housing (1)
and secure it with the Trigger Pin (11).
2. Install the Throttle Valve Face (6) on the
Throttle Valve (5).
3. Install the Throttle Valve stem (8), Throttle
Valve and Throttle Valve Spring (7).
4. Install the Air Strainer Assembly (9) and
tighten it to 30 to 35 ft-lb (40.5 to 47.5
Nm) torque.
Assembly of the Motor
1. Using a sleeve that will contact only the
outer ring of the bearing, press the Front
Rotor Bearing (24) into the Front End Plate
(30) and the Rear Rotor Bearing (23) into
the Rear End Plate (31).
2. Slip the Front End Plate and Bearing over
the splined hub of the Rotor (22).
3. Grasp the splined hub of the Rotor in
leather-covered or copper-covered vise jaws
so that the Rotor is in a vertical position.
4. Dampen each Vane (29) with light oil and
insert a Vane into each vane slot.
5. Set the Cylinder (26) over the Rotor and
onto the Front End Plate.
6. Slide the Rear End Plate and Bearing onto
the rotor hub and against the Cylinder.
