Chevrolet 1980 Light Duty Truck Service Manual page 444

6A 1-26 IN-LINE 6
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 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.
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.
Fig. 6 A 1 -4 2 ~ R in g Gap Location
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 to make sure that
the ring is free. If binding occurs at any point the cause
should be determined, and if caused by ring groove, remove
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. 6A1-42):
a. Install oil ring spacer in groove and insert anti­
rotation tang in oil 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.
d. Flex the oil ring assembly to make sure ring is free.
If binding occurs at any point, the cause should be
determined, and if caused by ring groove, remove by
dressing groove with a fine cut file. If binding is caused by
a distorted ring, check a new ring.
e. Install second compression ring expander then ring
with gaps properly located.
f. Install top compression ring with gap properly
located.
9. Proper clearance of the piston ring in its piston ring
groove is very important to provide proper ring action and
reduce wear. Therefore, when fitting new rings, the
clearances between the surfaces of the ring groove should
be measured (fig. 6A1-43). (See Specifications.)
LIG H T T R U C K S ER V IC E M ANUAL