Workshop Manual

4
36 Workshop Manual, TPD 1458E, issue 3 - Perkins Confidential: Green
400 Series
Piston rings
To fit Operation 4-4
Any letters or markings on the surface of the ring will always be positioned on the top face (facing upwards).
Use a suitable piston ring expander to fit the piston rings.
1 Fit the spring of the oil control ring (6) in the bottom groove of the piston with the latch pin (1) inside both
ends of the spring. Fit the oil control ring (4) over the spring (6). Ensure that the ring gap is at 180° to the latch
pin.
2 Fit the second ring (3) with the taper face into the second groove, with the word "TOP" towards the top of
the piston.
New second rings have a green identification mark which must be on the left of the ring gap when the ring is
fitted and the piston is upright.
The second ring has a step (5) at the top inside edge of the tapered face.
3 Fit the top ring (2) with the word 'TOP' towards the top of the piston.
New top rings have a red identification mark which must be on the left of the ring gap when the ring is fitted
and the piston is upright.
4 Ensure that the ring gaps are 90° apart.
H1057
90°
90°
1
4
6
3
5
2
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M
A
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