F
OR
M
ODELS
: JGI, JGM, JGN, JGP
AND
JGQ
S
ECTION
5 - M
AINTENANCE
PAGE 5-32
readings, taken without the use of feelers are to be used for acceptance. Copy Table 5-3 and
record calculations and readings.
T
ABLE
5-3 F
EELER
T
HICKNESS
TO
C
ORRECT
FOR
P
ISTON
W
EIGHT
If readings are not within acceptable limits after replacing worn parts and correcting any pip-
ing misalignment, the piston rod assembly should be replaced.
Piston Rings
JGI, JGM, JGP, JGN and JGQ cylinders use one-piece angle cut filled Teflon piston rings.
Determining Ring Wear:
Ariel recommends replacing rings when the end gap has increased three times the new
dimension. To measure the end gaps, insert the rings in the cylinders without pistons. (See
Table 1-7 on page 1-12 or Table 1-9 on page 1-14 for new end gap dimensions.)
Removal:
See paragraph 3. at “Piston and Rod” on page 5-27 for piston ring removal.
Piston Rings - Installation
1.
Place the rings over the grooves in the piston. Compress the Teflon one-piece
rings by hand.
2.
With the rings fully compressed in the grooves, insert the rod and piston into the
cylinder. Make sure the rings stay in place while inserting the piston and rod.
NOTE: RING GAPS ARE TO BE STAGGERED AROUND THE PISTON, RATHER THAN
IN LINE.
3.
Follow the steps under “Piston and Rod - Installation” on page 5-30.
Wear Bands
1-3/4JG-FS-HE and 1-3/4SG-FS-HE cylinder class pistons use a one-piece angle cut Teflon
wear band.
LINE
THROW NUMBER:
1
2
1.
Top Feeler Clearance
2.
Line 1 (Divided by 2)
3.
Line 2 - 0.003 in.
(-0.08 mm)
- 0.003 in.
(-0.08 mm)
- 0.003 in.
(-0.08 mm)
4.
Bottom Feeler Thickness
5.
Vertical - Piston @ CE
0
0
6.
Vertical - Piston @ HE
