The Boom Cylinders Need To Be Inspected For Cracks On Certain 231D, 235, 235B, And 235C Excavators Caterpillar

NOTE: If the Affected Product is located in a remote area, the cylinders can be replaced before failure instead of installing the guard. Replacement before failure is only permissible with Product Support Representative Authorization. For audit purposes a copy of the authorization should be retained at the dealership.

NOTE: Special reporting is required for warranty payment. Please see Pages 4 and 5 for details.

NOTE: This Revised Service Letter replaces the February 20, 1991 (Revised March 1991) Service Letter. Changes were made to the Action Required and to the reporting requirements.

If the Affected Product is operating exclusively in "log handling" or "building logging roads", and this Program has not been completed, make note of the change to the Action Required for the Affected Product. See Step 5.

Problem

The boom cylinders need to be inspected for cracks on certain 231D, 235, 235B, and 235C Excavators. A guard may need to be installed around the boom cylinder nearest the cab or the boom cylinder(s) may need to be replaced. Affected product equipped with earlier type boom cylinders do not require installation of the guard.

Affected Product
Model & Identification Number

Group 1

231D (1NK44,1NK56,1NK57,1NK61,1NK64,1NK65,1NK68,1NK89,1NK90,1NK93,1NK99,1NK100,1NK102,1NK115,1NK116,1NK122,1NK124,1NK126,1NK128,1NK138,1NK142,1NK212)

235 (32K1-3473;64R1-1567;81X1-491;83X1-511)

Group 2

235 (32K3474-4186;64R1568-2355;8lX492-554;83X512-1401)

235B (7WC1-947;9PC1-650;1FD1-354;4ED1-648)

235C (4DG30,4DG32,4DG35,4DG39,4DG47-49,4DG57,4DG58,4DG60,4DG65,4DG70-72,4DG74,4DG84,4DG92-94,4DG99,4DG102,4DG103,4DG106,4DG110,4DG111,4DG114,4DG118,4DG119,4DG129,4DG130,4DG132,4DG135,4DG144,4DG145,4DG149,4DG153,4DG155,4DG157,4DG162-164,4DG170,4DG171,4DG173-178,4DG180-184,4DG186,4DG188,4DG196,4DG202,4DG206,4DG207,4DG209-211,4DG218,4DG221,4DG224,4DG225,4DG227,4DG229,4DG234,4DG235,4DG243-247,4DG253-255,4DG265-268,4DG272,4DG274,4DG276,4DG277,4DG283-286,4DG289,4DG291,4DG294,4DG296,4DG298,4DG301-305,4DG307,4DG309-312,4DG314,4DG316,4DG317,4DG319,4DG320;3WG27-29,3WG44,3WG46,3WG60,3WG114,3WG119,3WG121,3WG123,3WG126)

Parts Needed

Dealers will need to order parts for this Program.

4C4736 Liquid Penetrant Kit to be used as required on all machines.

Group 1

If cracks are found and the excavator is equipped with an 8J4582 Cylinder Assembly or an 8J4589 Cylinder Group.

1 - 4E9095 Clamp As.

1 - 4E9096 Clamp

1 - 4E9430 Adapter

2 - 5P2424 Bolt - mounting adapter to clamp as.

1 - 0R3278 Cylinder As.

1 - 8T1461 Cylinder Seal Kit

4 - 8T4223 Washer - bolts clamps around cylinder as.

2 - 8T4835 Bolt - bolts clamps around cylinder as.

4 - 8T5360 Washer - existing lines mounting bracket to adapter

2 - 8T7971 Washer - mounting adapter to clamp as.

2 - 6V8188 Nut

2 - 7X0312 Bolt - existing lines mounting bracket to adapter

2 - 7X0317 Bolt

2 - 7X0447 Nut

Quantities listed are per cylinder

Group 2

If cracks are found and the excavator is equipped with a 4T1688 Cyl. As. or a 4T1689 Cyl. Gp.

1 - 4E9095 Clamp As. (2 Req'd if equipped with boom lower check valves)

1 - 4E9096 Clamp (Not Req'd if equipped with boom lower check valves)

1 - 0R3122 Cylinder As.

1 - 8T1461 Cylinder Seal Kit

4 - 8T4223 Washer - bolts clamps around cylinder as.

2 - 8T4835 Bolt - bolts clamps around cylinder as.

2 - 6V8188 Nut

Quantities listed are per cylinder

Parts required for installation of guard when no cracks are found and the excavator is equipped with a 4T1688 Cyl. As. or a 4T1689 Cyl. Gp.

1 - 9U2232 Guard As.

2 - 4E8646 Clamp-Half

4 - 2H3788 Nut

4 - 8T4223 Washer

4 - 7X0325 Bolt

Action Required

Parts Stock

Remove all 6E3474, 8J4582, 8J4589, 0R1054, 4T1688, 4T1689, and 9T9996 Cylinder Assemblies or Cylinder Groups from parts stock.

Affected Product

1. Use the 4C4736 Liquid Penetrant Kit and inspect the boom cylinder tubes for cracks. See Special Publication SEBD0996 "Instructions for Finding Cracks at Welded Blocks on 235 Boom Cylinders Using 4C4736 Liquid Penetrant Kit".

2. If no crack is found on Group 2 Affected Product, or any earlier machines that have been updated to the later type cylinder, it is necessary to install a guard on the cylinder closest to the cab. Do not install the guard on earlier "single block type" cylinders. See the attached procedure.

3. If a crack is found in a cylinder at the welded block, install the new parts listed under the heading Parts Needed.

4. Record the normal "Application", "Soil Conditions", and "Failure Model" as required for filing the claim.

5. Replace both boom cylinders on machines operating exclusively in either "log handling" or "building logging roads", regardless of whether cracks are found.

Owner Notification

U.S. and Canadian owners will receive the attached Owner Notification.

Service Claim Allowances

Parts Stock

Submit one claim for all 6E3474, 8J4582, 8J4589, 0R1054, 4T1688, 4T1689, and 9T9996 Cylinder Assemblies or Cylinder Groups removed from parts stock.

Affected Product

NOTE: This is a 1-hour job to inspect both boom cylinders, a 1-hour job to install the guard, and a 4.5-hour job per cylinder to install a new cylinder.

NOTE: No warranty payments will be made without proper reporting on excavator applications and inspection findings.

Use a combination of a number and two letters from the following lists for reporting purposes. Use the first three to four positions in the findings/comment section (block 22 in the illustration) of the Warranty Claim Form to report the normal application, soil conditions, and failure mode.

Application