REPAIR INSTRUCTIONS
Page 177
INSPECTION
Inspect the piston ring grooves, lands, piston skirt
and combustion bowl for wear, scuffing, cracks or
blow-by. Pistons are NOT repairable. Discard the
piston if it is damaged.
Do not stamp or engrave on TOP of the piston.
Doing so will reduce piston life.
To ensure that pistons are reinstalled in the same
cylinders, the pistons must be tagged with the
corresponding cylinder number when removed
during disassembly.
Piston Ring Replacement
[212 NV]
Before installing piston rings, check the keystone
ring groove wear and ring end gap.
1. Place a piston ring in the cylinder sleeve.
Push it down into the sleeve with an inverted
piston to ensure that it is positioned squarely
in the sleeve.
2. Using thickness gauges, check the ring end
gap. Refer to Fits and Limits in the
SPECIFICATIONS section for end gap
tolerance. All rings to be used should be
checked in this manner.
Do not file or grind chrome-plated piston rings.
This may cause the chrome to flake, resulting in
ring failure.
KEYSTONE RING GROOVE CHECK
Refer to Figure 170.
Keystone piston-ring groove gauge J 29510
consists of two 0.120-inch (3.048 mm) diameter
pins (1) connected at the ends by two springs (2).
170
Figure 170 — Ring Groove Gauge
1. Place the pins of the keystone piston ring
groove gauge J 29510 opposite each other
in the groove to be measured. The pins will
be held in position by the springs.
Refer to Figure 171.
1. Pins
2. Springs
5_106_00.bk Page 177 Friday, August 4, 2000 11:17 AM
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