Product Support Program For Cylinder Head Gasket Failures On Certain D6D, D6H, D7G, And D7H Tractors; 12G, 14G, And 140G Motor Graders; D25C, D25D, D30C, D30D, D35C, D250B, D300B, D350C, And D350D Articulated Dump Trucks; Challenger 65 Tractors; Caterpillar

NOTE: 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.

NOTE: This Program can only be administered after a failure occurs. The decision whether to apply the Program is made by the dealer. When reporting the repair, use "PS0453" as Part Number, "7755" as Group Number, and "96" as Description Code.

NOTE: This Revised Service Letter replaces the June 20, 1990 (Revised March 1991) Service Letter. Changes have been made to include the information in the October 7, 1991 Service Letter Supplement. Changes were also made to the Affected Product, Parts Needed, Action Required, and Service Claim Allowances.

Termination Date

Problem

The 7N7999 Cylinder Head Gasket may fail on certain D6D, D6H, D7G, And D7H Tractors; 12G, 14G, And 140G Motor Graders; D25C, D25D, D30C, D30D, D35C, D250B, D300B, D350C, And D350D Articulated Dump Trucks; Challenger 65 Tractors; 235C Excavators; 528 Skidders; 615C, 627E, And 637E Scrapers; 815B And 816B Compactors; 966D And 966E Loaders; And 973 Loaders allowing compression to leak by the combustion seal either externally or into the cooling system.

Affected Product
Model & Identification Number

D6D (6HC1-1967)

D6H (4RC1-2518; 8FC1-1029; 5HF1-369; 6CF1-584; 3ZF1-1222; 2TG1-515; 3YG1-522; 4LG1-864; 1FJ1-476)

D7G (65V1-7294)

D7H (5BF1-856; 79Z1-2324; 80Z1-803)

12G (3WC1-1333; 61M1-13494)

14G (03L1-212; 96U1-7824)

140G (72V1-12582; 13W1-775)

D25C (9YC1-1011)

D25D (1HK1-185)

D30C (7ZC1-257)

D30D (3AJ1-128)

D35C (2GD1-124)

D250B (5WD1-399)

D300B (4SD1-481)

D350C (8XC1-404)

D350D (9RF1-162)

CH65 (7YC1-1557)

235C (5AF1-858; 2PG1-558; 3WG1-184; 4DG1-430)

528 (96C1-720; 97C1-375)

615C (5TF1-327)

627E (6EB1-649; 6FB1-613; 6GB1-776; 6HB1-776)

637E (1FB1-400; 1HB1-456; 1JB1-695)

815B (17Z1-1121)

816B (15Z1-981)

966D/E (7BB101-199; 94X6489-9030; 99Y5315-6954)

973 (86G1-1031)

Parts Needed

^*1 - Gasket Kit (Use appropriate gasket kit)

^**1 - 9L5855 Insert (.030)

or

9L5856 Insert (.035)

or

9L5857 Insert (.040)

or

9L5858 Insert (.045)

1 - 4M2969 Gasket-Oil Pan

^***1 - 2P8889 Liner

^**3 - 5S6670 Seal

^**1 - 2W6134 Band

Action Required

After a cylinder head gasket fails, check the fuel settings for probable contribution to the gasket failure. If the engine is found to have been adjusted in excess of specification, this Program cannot be applied.

Follow the procedures in the Service Manual to make the necessary repairs using a new 7E6176 Cylinder Head Gasket. The repairs will include lifting the cylinder packs and inspecting for wear/erosion under the liner flanges. Where measurable wear or erosion exists on the cylinder block top deck, make a repair using stainless steel inserts and possibly a new liner. See Special Instruction FMO55228 to install the inserts. Use only stainless steel inserts. If the bottom surface of the cylinder head is damaged, repair by resurfacing or use a Remanufactured cylinder head. The spacer plate should also be inspected for erosion and warpage. Liner projection measurements should be recorded in the dealer service report for reference.

When installing the cylinder head, make sure the head bolts and washers are coated with 6V4876 Molykote.

Refer to the following articles:

Service Magazine, November 19, 1990 "New Head Gasket Used On 3306B Truck Engines"

Service Claim Allowances

NOTE: This is a 18-hour job.

NOTE: An additional 1-hour of labor per cylinder may be claimed if installation of a block insert is necessary.

Parts Disposition

Handle the parts in accordance with your Warranty Bulletin on warranty parts handling.