Doosan DCT9PS Operación Y Mantenimiento página 55

DISASSEMBLING THE DCT9PS AND DCT12PS PICKHAMMERS
GENERAL INSTRUCTIONS
• Clean the pickhammer outer surface.
• Do not disassemble the pickhammer any further than
necessary to replace or repair damaged or worn parts.
• Whenever grasping a pickhammer or a part in a vice,
always use leather or copper-covered vice jaws to protect
the surface of the part and help prevent distortion. Take
extra care with threaded parts and housings.
• Do not remove any part that is a press fit in or on a
subassembly unless the removal of the part is necessary
for repairs or replacement.
• Do not disassemble the breaker unless a complete set of
and O-rings is available for replacement.
DISASSEMBLY OF THE FRONTHEAD
Screw retainer models
Unscrew retainer (12) off the cylinder (1) and remove chisel
buffer (13) from inside retainer. Remove seal ring (8) from its
groove in the cylinder.
Latch retainer models
Remove nut (17) and fronthead pinch bolt (16) from the
fronthead (15). Lightly tap the fronthead (using a hide mallet if
necessary) off the cylinder (1).
Press or drift out the two fronthead spring pins (18, 19) and
remove the latch lever (20).
The plunger (22) and plunger spring (21) can be removed from
the fronthead.
MAIN DISASSEMBLY
Grip handle body (24) firmly in a vice (use leather or copper
covered vice jaws).
Remove muffler retaining clip (10) from its groove in the
cylinder (DCT9PS models only).
Insert three or four pieces of thin sheet steel ap proximately 8
mm wide, beneath the retaining lip of the muffler moulding (9)
(small diameter end). These will allow the rubber retaining lip
of the muffler to slide along over the groove in the cylinder and
ease removal of the muffler.
Slide off muffler (9) over the cylinder exposing the cylinder
flats.
Remove locking pin (7) from its hole in cylinder, the pin is
provided with an M4 internal thread to assist removal.
Remove the handle from the vice, invert the pickhammer
and grip the flats of the cylinder in the vice.
Use a pipe about 1.5 Meters long positioned through the
loop of the handle to first loosen and then completely
unscrew the handle assembly from the cylinder and
remove. – Warning – once the handle is unscrewed from
the cylinder the piston and valve parts will be free to fall
and could cause injury.
HANDLE DISASSEMBLY
Grip handle body (24) in leather or copper covered vice jaws
and unscrew throttle valve plug (29) using a 13 mm spanner.
Withdraw throttle spring (28), throttle ball (27) and throttle pin
(32).
Remove the trigger (25) by pressing or drifting out trigger pin
(26).
Unscrew quick release coupling (31) from inlet bushing (30).
The inlet bushing (30) can be removed if required though it is
assembled into the handle using a high strength retainer and
disassembly is not normally necessary.
CYLINDER DISASSEMBLY
Remove the spacing washer (6) and valve plate (5).
Slide off valve ring (4) from cylinder (1).
Allow piston (3) to slide out of the cylinder bore and be caught.
The nozzle (2) is pressed into the cylinder and retained with
Loctite 601 – do not disassemble unless replacement is
necessary.
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