Service Manual

MODEL 760 (HAMMER DROP) SERVICE
General operating instructions for this model
are contained in the Owner's Manual and should
be read thoroughly. The detailed drawings, repair
instructions and Disassembly/Assembly pro-
cedures must be studied carefully before any
repair work is started. This will insure quicker and
more precise repair of gun.
It is not always necessary to disassemble the
entire gun in repair work it is hoped that this sec-
tion will assist you in diagnosing the repair pro-
blem and will speed up repair time.
TROUBLE SHOOTING
PROBLEM I — Gun Will Not Fire
POSSIBLE CAUSES
REPAIR PROCEDURES
1. Interlock 760-087 da-
maged or not working
properly.
2. Bolt Lever 760-091 is
open or not completely
in closed position.
1. See Disassembly/Assembly
Procedures Receiver Group (VI).
2. Inspect Interlock 760-087 for
wear or damage.
3. If necessary to replace, pry off
Interlock Retainer 760A090 and
remove Interlock Spring 760A088
Interlock 760-087 and Interlock
Bushing 760-089.
1. If Bolt Lever 760-091 is open or
not completely closed it will inter-
fere with Interlock 760A087 and
prevent gun from firing.
PROBLEM II — Leaks
POSSIBLE CAUSES REPAIR PROCEDURES
1. Defective Valve Stem
Assembly 1322-011.
2. Defective Check
Valve 1400A029.
1. See Disassembly/Assembly
Procedures — Valve and Tube
Group (X)
2. Valve Stem Assembly 1322-011,
must be replaced if damaged or
defective.
1. If Lever kicks back when pump-
ing gun, it will indicate that the
Check Valve 1400A029 is defec-
tive.
2. See Disassembly/Assembly
Procedures — Valve and Tube
Group (X).
3. Replace Check Valve
1400A029.
PROBLEM Ml — Low Power
POSSIBLE CAUSES
REPAIR PROCEDURES
1. Seal on Valve Stem
Assembly 1322-011 is
distorted allowing too
little air pressure into
Exhaust Hole.
2. Valve Leaks
3. Compressed or defec-
tive Pump Cup 766-035.
4. Defective or missing
Gasket 130-036.
5. Connecting Rod
Assembly 1322-019 is
too short and will not
compress air in Valve
Assembly.
1. See Disassembly/Assembly
Procedures — Valve and Tube
Group (X).
2. Check Seal on Valve Stem
Assembly 1322-011 and replace
entire Assembly if necessary.
1. See Problem I — Leaks — Trou-
ble Shooting Section.
1. See Disassembly/Assembly
Procedures — Lever and Pump
Group (III).
2. Inspect and replace Pump Cup
766-035 if necessary.
1. See Disassembly/Assembly
Procedures — Valve and Tube
Group (X).
2. Replace Breech Gasket 130-036
if necessary.
1. One way to check for this
cause is to pump gun two times
and fire. If gun does not expel
pellet, then connecting Rod
Assembly 1322-019 may need to
be replaced.
2. See Disassembly/Assembly
Procedures — Lever and Pump
Group (III).
PROBLEM IV — Gun Fails To
Exhaust Air
POSSIBLE CAUSES
REPAIR PROCEDURES
1. Gun has been over
pumped.
1. If gun pumps very hard,
compression build-up will indicate
gun has been over-pumped, not
allowing Hammer to exhaust any
air.
2. See Disassembly/Assembly
Procedures — Valve and Tube
Group (X).
NOTE: Place Valve Assembly
760A101 on bench with Valve
Stem Assembly 1322-011 facing
up and exhaust hole away from
you. Then hit Valve Stem
Assembly 1322-011, thereby ex-
pelling the air.