Product Safety Information
Failure to observe the following warnings, and to avoid these potentially hazardous situations, could result in death or serious
injury.
Read and understand this and all other supplied manuals before installing, operating, repairing, maintaining, changing accessories
on, or working near this product.
Always wear eye protection when operating or performing maintenance on this tool. The grade of protection required should be
assessed for each use and may include impact-resistant glasses with side shields, goggles, or a full face shield over those glasses.
Always turn o the air supply, bleed the air pressure and disconnect the air supply hose when not in use, before installing, removing
or adjusting any accessory on this tool, or before performing any maintenance on this tool or any accessory.
Note: When reading the instructions, refer to exploded diagrams in parts Information Manuals when applicable (see under Related Documentation
for form numbers).
Lubrication
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Each time a Model 772 Air Hammer is disassembled for maintenance,
repair or replacement of parts, lubricate the tool as follows:
Inject approximately 3 cc of oil into the air inlet and operate the tool
for 5 seconds to coat the internal parts with oil.
Disassembly
General Instructions
Do not disassemble the tool any further than necessary to replace
or repair damaged parts.
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 and help prevent distortion. This is particularly true of
threaded members and housings.
Do not remove any part which is a press t in or on a subassembly
unless the removal of that part is necessary for repairs or
replacement.
Do not disassemble the Air Hammer unless you have a complete
set of new gaskets and O-rings for replacement.
Disassembly of the Air Hammer
Remove the tool Retainer (16).
Slide the Exhaust Deector (13) o the Barrel (15).
Clamp the ats of the Barrel in leather-covered or copper-covered
vise jaws with the Oset Handle Assembly (1) upward.
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2.
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3.
Carefully unscrew the Handle.
Remove the Valve Cap (10), Valve (11), Valve Spacer (9), Valve
Seat (8), two Dowel Pins (12), and the Piston (14).
Disassembly of the Throttle Mechanism
Unscrew the Throttle Valve Bushing Assembly and withdraw the
throttle mechanism. Remove the Throttle Valve Spring (7).
Press the Throttle Valve (2) from the Throttle Valve Button (4).
Remove the Throttle Valve Bushing Assembly from the Throttle
Valve.
If required, remove the Throttle Valve Face (3) and the Throttle
Valve Bushing Seal (6).
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5.
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Assembly
General Instructions
Whenever grasping a tool or part in a vise, always use leather-
covered or copper-covered vise jaws. Take extra care with
threaded parts and housings.
Always clean every part and wipe every part with a thin lm of oil
before installation.
Apply a lm of O-ring lubricant to all O-rings before nal
assembly.
Assembly of the Throttle Mechanism
If required, replace the Throttle Seal Bushing Seal (6) and the
Throttle Valve Face (3) onto the Throttle Valve Bushing
Assembly (5).
Press the Throttle Valve (2) into the Throttle Valve Button (4).
Clamp the Oset Handle Assembly (1) of the Air Hammer in
leather-covered or copper-covered vise jaws with the opening
upward.
Place the large end of the Throttle Valve Spring (7) into the Oset
Handle Assembly. Screw the Valve Bushing Throttle Valve into the
Handle and tighten to 30 ft-lb (40 Nm) minimum.
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2.
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4.
Assembly of the Air Hammer
Clamp the Barrel (15) in leather-covered or copper-covered vise
jaws with the Handle end up.
Place the Piston (14) into the Barrel.
Place the Dowel Pins (12) into the dowel pin holes in the Barrel.
With the Dowel Pins going through the dowel pin holes in the
Valve Seat (8) and Valve Spacer (9), place the Seat and Spacer onto
the Barrel.
Place the Valve (11) on the Valve Spacer.
With the Dowel Pins going through the dowel pin holes in the
Valve Cap (10), place the Cap on the Barrel.
Screw the Oset Handle Assembly (1) onto the Barrel tighten to
120 ft-lb (162 Nm) torque.
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