8
JCT-4660 series Paving Breaker
Back head assembly
1.
Place chamfered side of throttle valve stem
guide into the back head and tap into
position.
2. Ream the guide with a 0.312” (7.93 mm)
reamer tool.
3.
Set throttle valve lever into the back head.
4.
Place a 0.312” (7.93 mm) steel rod into the
hole and hammer in the pin.
5.
Apply a light film of grease on rubber handle
and slide onto handle.
6.
Assemble the plugs on both sides of back
head. See torque specifications chart for the
torque setting.
7.
Place throttle valve o-ring in position where
the cylinder will meet.
8.
Insert oil control felt onto top portion of back
head and assemble the oil control plug.
Air inlet assembly
1.
Place the #P91222 O-ring onto the air inlet
swivel.
2.
Place the #P91237 O-ring onto the air inlet
swivel nut.
3.
Assemble air inlet swivel into air inlet swivel
nut and tighten nut.
Completing assembly
1. Stand the front head assembly in vertical
position.
2.
Assemble tappet seat and cylinder onto front
head, making sure the retainer nut and
exhaust port on cylinder are in line with each
other.
3.
Place the front head bolts into the holes.
4.
Assemble front head bolt springs, front head
lock washer, and tighten front head bolt nut.
A minimum of three bolt threads should be
visible.
5.
Assemble valve seat, valve, valve chest, and
valve guide into cylinder.
Note
: Valve chest
and valve guide must align with knock
placement. The valve has no orientation.
6.
Install valve chest dowel pin.
7.
Install five cylinder plugs into cylinder.
8.
Set air inlet screen into the exhaust portion
of cylinder.
9. Install air inlet assembly. See torque
specification chart.
10. Place throttle valve spring onto throttle valve
and install into cylinder.
11. Lightly grease the inner diameter of plunger,
insert plunger spring, and place on top of
valve guide.
12. Place back head on top of cylinder and put
back head bolts from underneath into the
four holes.
13. Assemble lock washer and fasten back head
bolt nuts. See torque specification chart for
bolt tightness.
14. Assemble back head with lever in line with
cylinder exhaust port.
15. Remove oil fill plug in the back head and refill
spindle oil tank.
16.
Tighten oil tank plug. See torque
specification chart.
Before operating a newly rebuilt tool, pour a few
ounces of air tool oil into air inlet. Also, allow a
break-in period for the tool by running it at reduced
air pressure for a short time until proper function
is confirmed.