MAC TOOLS AW434C-Serie Betriebshandbuch Seite 26

Always wear eye protection when operating or
performing maintenance on this tool.
Always turn off the air supply and disconnect the air
supply hose before installing, removing or adjusting
any accessory on this tool or before performing any
maintenance on this tool.
LUBRICATION
Each time an AW434C or AW434C–2 Air Wrench is
disassembled for maintenance and repair or replacement
of parts, lubricate the wrench as follows:
1. Work approximately 6 to 8 cc of Mac Tool Pneumatic
Grease into the impact mechanism. Coat the Anvil
(41) lightly with grease around the Hammer Case
Bushing (37). Inject approximately 1 to 2 cc of the
recommended grease into the Grease Fitting (2).
2. Use Mac Tool Pneumatic Oil for lubricating the
motor. Inject approximately 1 to 2 cc of the
recommended oil into the air inlet before attaching
the air hose.
DISASSEMBLY
General Instructions
1. Do not disassemble the wrench further than necessary
to replace or repair damaged parts.
2. Whenever grasping a tool or part in a vise, always use
leather–covered or copper–covered vise jaws to
protect the surface of the part or tool and help prevent
distortion. This is particularly true of threaded
members and housings.
3. Do not remove any part which is a press fit in or on a
subassembly unless the removal of that part is
necessary for repairs or replacement.
4. Do not disassemble the wrench unless you have a
complete set of new gaskets and O–rings for
replacement.
Disassembly of the Air Wrench
1. Clamp handle of the wrench in a vise with
leather–covered or copper–covered jaws with square
driver upward.
2. Unscrew and remove the three Hammer Case Cap
Screws (39).
3. While lightly tapping on end of Anvil (41) with a
plastic hammer, lift off Hammer Case (34).
4. Grasp Hammer Frame (30) and carefully lift off entire
impact mechanism, making certain not to drop two
Hammer Pins (31). If it is necessary to disassemble
the impact mechanism, refer to Disassembly of the
Impact Mechanism. If it is unnecessary to
disassemble the impact mechanism, set it aside intact.
Disassembly of the Impact Mechanism
1. Set mechanism, driver end up, on a workbench.
Note the twin hammers within the Hammer
Frame. These are identical but must be placed in
the Hammer Frame in a certain relationship. Using
a felt–tipped pen, mark the top hammer "T↑" and
the bottom hammer "B↑" with the arrows pointing
upward. Mark both Hammers on the same end.
2. With mechanism sitting upright on workbench, slowly
rotate Anvil in a clockwise direction until it comes up
solid.
If you continue to rotate the Anvil, it will cam the
Hammers out of engagement. Don't do this; merely
rotate the Anvil until it comes up solid.
MAINTENANCE SECTION
3. Hold Hammer Frame firmly and, without disturbing
4. With Anvil removed, lift out the two Hammer Pins.
5. Remove the Hammers.
Disassembly of the Motor
1. Lift Rear Hammer Frame Washer (32) and two Motor
2. Grasp splined end of Rotor (19) and pull assembled
3. Lift Front End Plate (26) and Front Rotor Bearing
4. Remove Cylinder (23) and Vanes (25).
5. Remove Rear Rotor Bearing Retainer (22).
6. Lift Rear End Plate (27) and Rear Rotor Bearing (20)
7. Unscrew Air Strainer (10) and remove it.
8. Withdraw Throttle Valve Spring (8), Throttle Valve
9. Remove Trigger Pin (12) and Trigger (11).
10. Unscrew Reverse Valve Knob Screw (17) and remove
11. While slowly rotating Reverse Valve (13), withdraw it
General Instructions
1. Always press on the inner ring of a ball–type bearing
2. Always press on the outer ring of a ball–type bearing
3. Whenever grasping a tool or part in a vise, always use
4. Except for bearings, always clean every part and wipe
5. Apply O–ring lubricant to every O–ring before
6. Check every bearing for roughness. If an open bearing
Assembly of the Reverse Valve
1. Make certain Reverse Valve Bushing Seals (5) are
2. Dampen Reverse Valve (13) with light oil. Install
26
the hammers, gently lift Anvil, simultaneously
rotating it clockwise about 1/8 of a turn, from the
Hammer Frame.
The twin hammers are now free to slide from the
Hammer Frame when the Hammer Pins are
removed. Do not drop the Hammers (33).
Clamp Washers (29) from front of motor.
motor from Motor Housing (1).
(21) from splined end of the Rotor.
from Rotor.
(6), and Throttle Valve Stem (9). Remove Throttle
Valve O–ring (7) from Throttle Valve.
Reverse Valve Knob (16).
from Reverse Valve Bushing (4).
Be careful not to lose the Reverse Valve Detent Ball
(14) and Spring (15) from the hole in the side of the
Reverse Valve.
ASSEMBLY
when installing the bearing on a shaft.
when installing the bearing in a bearing recess.
leather–covered or copper–covered vise jaws to
protect the surface of the part and help prevent
distortion. This is particularly true of threaded
members and housings.
every part with a thin film of oil before installation.
assembly.
must be cleaned, wash it thoroughly in clean solvent
and dry it with a clean cloth. Sealed or shielded
bearings should never be cleaned. Work grease
thoroughly into every open bearing before
installation.
properly located in undercuts in Reverse Valve
Bushing (4).
Reverse Valve Detent Spring (15) followed by
Reverse Valve Detent Ball (14) in hole in Reverse
Valve. With the Air Wrench in an upright horizontal
position, and while facing handle end of the Air
Wrench, slowly rotate the Reverse Valve and insert it
from left to right in the splined end of Reverse Valve
Bushing.