Chevrolet 1980 Light Duty Truck Service Manual page 480

6A4-28 SMALL BLOCK
PISTON PIN
INSTALLER
J -2 4 0 8 6 -9
F ig . 6 A 4 - 5 3 - - l n s t a l l i n g P i s t o n Pin
3. Using piston pin installer, J-24086-9, press the
piston pin into the piston and connecting rod (fig. 6A4-53).
After installer hub bottoms on support
NOTICE:
assembly, do not exceed 5000 psi pressure, as this could
cause structural damage to the tool.
4. Remove piston and connecting rod assembly from
tool and check piston for freedom of movement on piston
pin.
Piston Rings
All compression rings are marked on the upper side of
the ring. When installing compression rings, make sure the
MARKED SIDE IS TOWARD THE TOP OF THE
PISTON. The top ring is chrome faced, or treated with
molybdenum for maximum life. The second compression
ring is a tapered face acting as both a compression and oil
control ring.
The oil control rings are of three piece type, consisting
of two segments (rails) and a spacer.
1. Select rings comparable in size to the piston being
used.
2. Slip the compression ring in the cylinder bore; then
press the ring down into the cylinder bore about 1/4"
(6.5mm) (above ring travel). Be sure ring is square with
cylinder wall.
3. Measure the space or gap between the ends of the
ring with a feeler gage (fig. 6A4-54).
PRESS
fixture and support assembly.
F i g . 6 A 4 - 5 4 - - M e a s u r i n g R i n g G a p
4. If the gap between the ends of the ring is below
specifications, remove the ring and try another for fit.
5. Fit each compression ring to the cylinder in which
it is going to be used.
6. If the pistons have not been cleaned and inspected
as previously outlined, do so.
7. Slip the outer surface of the top and second
compression ring into the respective piston ring groove and
roll the ring entirely around the groove (fig. 6A4-55) to
make sure that the ring is free. If binding occurs at any
point, the cause should be determined. If binding is caused
by ring groove, correct by dressing with a fine cut file. If
the binding is caused by a distorted ring, check a new ring.
8. Install piston rings as follows (fig. 6A4-56):
a. Install oil ring spacer in groove and insert anti­
rotation tang (where applicable) in drilled hole.
b. Hold spacer ends butted and install lower steel oil
ring rail with gap properly located.
c. Install upper steel oil ring rail with gap properly
located.
LIG H T T R U C K S ER V IC E M AN UAL