PowerTech 6105HF - Check Piston Compression Ring Groove Wear-6125 Engines

Cylinder Block, Liners, Pistons, and Rods
02
030
23
RG,RG34710,116 –19–01NOV00–1/1
Check Piston Compression Ring Groove
Wear—6125 Engines
RG8522 –UN–10DEC97
Using JDG1022 - Top Groove
RG8523 –UN–10DEC97
Using JDG1022 - Second Groove
A—JDG1022 Ring Groove Wear Gauge
B—Piston with Good Ring Groove
C—Acceptable Clearance
D—Piston with Worn Ring Groove
E—Gauge Shoulder Contacting Piston Ring Land
NOTE: Earlier engines with and RE66125 pistons have
4-mm compression rings. Later engines with
RE503969 and RE505901 pistons have 3-mm
compression rings. Piston part numbers are
marked on top of pistons for identification.
The illustrations to the right shows use of
JDG1022 Wear Gauge on earlier pistons. Use of
JDG1335 on later pistons is similar except the two
compression ring grooves are the same on these
pistons and only one side of the gauge is used to
check both.
Check grooves at several locations around the
circumference of piston crown. The word “TOP” on gauge
should always face top of piston.
Earlier RE66125 Pistons with 4-mm Rings:
Use the JDG1022 Ring Groove Wear Gauge (A), end
marked “G1”, to check wear of top compression ring
groove.
Use end marked “G2” of JDG1022 Ring Groove Wear
Gauge to check wear of middle compression ring groove.
If gauge shoulder contacts ring land of piston, ring groove
is worn. Replace piston and liner as a set.
If ring grooves are good (B), proceed with piston
inspection.
Later RE503969 and RE505901 Pistons with 3-mm
Rings:
Use JDG1335 Ring Groove Wear Gauge to check wear of
top two compression rings.
If gauge shoulder contacts ring land of piston, ring groove
is worn. Replace piston and liner as a set.
If ring grooves are good (B), proceed with piston
inspection.
CTM100 (06APR04) 02-030-23 P OWER T ECH 10.5 L & 12.5 L Diesel Engines
040604
PN=163