VALVE-CHECK 3612844 - Caterpillar

Caterpillar: Confidential Yellow
PARTS STOCK ACTION ONLY - REMOVE 8N1442 PISTON RINGS FROM PARTS STOCKS 3500 SERIES ENGINES - PI7127 - MAILED US AND CAN ADA, CACO, COFA, BRAZIL, CFEL, COSA
  The information supplied in this service letter may not be valid after the termination date of this program.   Do not perform the work outlined in this Service Letter after the termination date without first contacting your Caterpillar product analyst.
REMOVE 8N1442 PISTON RINGS FROM PARTS STOCKS 3500 Series Engines, 1215, PI7127 U-9 A-6 AU-7 B-2 C-7 E-8 O-7 parts stock action only Problem The 8N1442 Piston Rings - Oil may not be satisfactory for parts service. Some of the ring expanders have an incorrect number of segments, or the ends of the expanders are not properly machined. This will cause excessive oil consumption and possibly excessive liner wear. A new 7W2221 Ring is now available for parts service and is used in production engines. This ring uses a coil spring-type expander instead of the segment-type expander. Action Requested Remove all 8N1442 Rings from your parts stocks. Order the 7W2221 Ring for replacements. Warranty Allowances Submit one claim for all 8N1442 Rings. Parts Disposition Scrap the parts in accordance with your Warranty Bulletin on warranty parts disposition. Termination Date August 31, 1985.