4
51991057_ed3
Assembly of Handle
13. Install the new O-Rings (16) in its groove in the throttle valve.
14. If removed, press the throttle valve lever (15) in the throttle valve
(14).
15. Install the throttle valve assembly in the handle (8).
16. Insert the throttle valve locating pin (17) in its hole in the rear of
the handle to secure the throttle valve in the handle.
17. Install the plug (18).
18. Install one set of handle grip parts on the handle bolt (9). Slide
the washer (11) and grip (13) into the handle bolt (9) in order
listed.
19. Insert the handle bolt (9) through the handle (8).
20. Install the remaining grip (13) and washer (11) over the projecting
end of the handle bolt (9).
21. Install the lockwasher (12) and secure the handle with the nut
(10).
22. Install a new O-Ring (23) in its groove on the hose connection
(22).
23. Position the hose connection in the handle inlet port and secure
by screwing the hose connection cap into the handle.
24. Position the handle assembly over the cylinder (35), align the
assembly rod holes in the handle with the half-holes on each side
of the cylinder body, and slide the handle (8) into the cylinder
(35).
25. Slide the assembly rods (1) through the holes in the handle (8),
half-holes in cylinder (35) and piston stem bearing (51), and
through the holes in the fronthead
fl
ange (58).
26. Secure the jackhamer assembly by attaching assembly rod nuts
(2).
The Assembly Rods must be tight and under equal tension.
Loose or unequal Assembly Rod tension will cause misalignment
of internal parts which will promote breakdown of the Drill.
Apply 110-130 Lb-ft (149-176 Nm) of torque to each Assembly
Rod Nut.
27. Slide the blower tube (5) through the hole in the tube rubber (6)
until rubber is seated under tube collar.
28. Push the blower tube/rubber assembly through the tube hole
in the handle (8) and through the center hole in the ri
fl
e bar and
piston until the rubber seats in the counterbore in the handle.
29. Install a new O-Ring (4) on the tube retainer (3) and screw the
retainer (3) into the handle to secure the tube. Assembly of
Beavertail type Steel Holder
30. Press the steel holder bolt bushings (59) into the lugs of the
fronthead (58).
31. Place the steel holder bolts (61) on the steel holder trunnions.
32. Position the steel holder and bolt assembly so that the bolts
protrude through the fronthead lugs.
33. Place the steel holder bolt springs (62) over the steel holder bolts
(61) and secure by attaching the steel holder bolt nuts (63).
34. Compress the springs (62) by tightening the nuts (63) until the
retaining rings (64) can be inserted in the grooves in the steel
holder bolts (61).
35. Back-o
ff
the steel holder bolt nuts (63) until they rest against the
retaining rings (64).
Performance Testing
A reconditioned jackhamer should be tested before it is sent back to
the job. Before connecting the air hose, check to see that the air line
lubricator is
fi
lled with the proper lubricant. Refer to the instruction
manual for jackhamers for speci
fi
cations.
Pour a small amount of rock drill oil directly into the air inlet for initial
lubrication. The jackhamer should start with little air pressure, with
the piston reciprocating smoothly.
Let the jackhamer run-in slowly at reduced pressure long enough
to see that it is in good working order. If the jackhamer stalls, turn
o
ff
the air immediately. This indicates binding due to tight
fi
ts or
perhaps unevenly tightened assembly rods. Check rod tension
fi
rst,
then start the jackhamer again. After a short period of operation, a
de
fi
nite rhythm should develop and an even exhaust note will be
heard. The jackhamer may become warm but should not overheat. If
erratic operation or stalling persists, disassemble the jackhamer and
check for binding parts.
After the initial period of low pressure operation, check the
performance of a reconditioned Jackhamer with that of a new
Jackhamer by comparing its speed under similar conditions and with
normal air pressure. Once testing is completed, install plastic plugs or
caps in all ports to keep out dirt until the machine is back in service.
Troubleshooting Guide
Trouble
Probable Cause
Solution
Jackhamer will not
start
Plugged exhaust port or air passages caused
by dirt or hose particles.
Dismantle Jackhamer, clean out all ports and air passages. Keep
the air hose in good condition; never use a soft deteriorated hose.
Stuck valve due to gummy oil or incorrect
assembly.
Remove Backhead completely. Dismantle Valve and clean
parts. Never use dirty oil or oil that does not conform to the
recommended speci
fi
cations.
Frozen piston due to improper lubrication.
Dismantle Jackhamer to remove piston. Repair piston by placing
in a high speed lathe and dressing with
fi
ne emery cloth. Never
run Jackhamer without the proper lubricating oil in the air line
lubricator.
Side Rods tightened unevenly, causing
binding.
Check Jackhamer for correct assembly and retighten Side Rods
evenly. Torque Side Rod Nuts between 110 - 130 ft-lb (149 - 176
Nm) torque.
Jackhamer loses
power rapidly
Restriction in air supply line.
Never allow the air supply to kink or make sharp bends.
Air supply line too long.
As a general rule, keep the air supply line under 50 ft. (15 m).
Diameter of air supply line too small.
A 3/4 in. (19 mm) diameter air supply is recommended for the
Jackhamer.
Freezing at exhaust
ports
Excessive moisture in the air supply line
Install moisture traps in the air supply line or add antifreeze
lubricant directly through the air inlet. Use “KILFROST”* anti-freeze
lubricant or equivalent.
Summary of Contents for Jackhamer JH40
Page 7: ...Notes...
