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Piston Compression Rings
Technical Service Bulletin
Technical Service Bulletin: tsb101363
Piston Compression Rings
Released Date: 02-Feb-2004
Piston Compression Rings
Warranty Statement
The information in this document has no effect on present warranty coverage or repair practices, nor does it authorize
TRP or Campaign actions.
Contents
The purpose of this Service/Parts Topic is to inform the field of:
Changes to the compression rings used on the QSV81 and QSV91.
Clarify the placement of the rings on the piston.
Identify the proper orientation of new and used compression rings on the piston.
Updates Procedure 001-047, Piston Rings.
The changes to the compression ring part numbers are identified in the table below:
Compression Ring
Old Part Number
New Part Number
Top Ring
4011497
3424955
Intermediate Ring
3424955
4012412
The piston rings are available in Piston Ring Set, Part Number 4011504. It consists of the following:
Part Number 4011504, Piston Ring Set
Top Compression Ring
3424955
Intermediate Compression Ring
4012412
Oil Control Ring
4012413
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Piston Compression Rings
Figure 1
The correct placement of the compression rings on the piston can be seen in Figure 1.
The proper orientation of the compression rings can be identified by the marking of 'TOP' and the last four digits of
the compression ring part number stamped on the top side of the ring. If the part number can not be found by gently
cleaning the top edge of the compression ring, Cummins Inc. does not recommend reuse.
The Top Compression Ring (1), Part Number 3424955, is marked as 'TOP' 4955.
The Intermediate Compression Ring (2), Part Number 4012412, Is marked as 'TOP' 2412.
Figure 2, Top Edge Chamfer
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Piston Compression Rings
If the compression ring must be reused, the top edge can be identified by a 30 degree chamfer on the face of the
ring.
Related Procedures
66-001-047 (/qs3/pubsys2/xml/en/procedures/66/66-001047.html)
Piston Rings (/qs3/pubsys2/xml/en/procedures/66/66-001047.html)
Last Modified: 02-Feb-2004
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