PRODUCT SUPPORT PROGRAM FOR REWORKING THE HYDRAULIC CABINET ON CERTAIN 794 AC, 796 AC, AND 798 AC OFF-HIGHWAY TRUCKS Caterpillar

PRODUCT SUPPORT PROGRAM FOR REWORKING THE HYDRAULIC CABINET ON CERTAIN 794 AC, 796 AC, AND 798 AC OFF-HIGHWAY TRUCKS

Usage:

TEBE9101-00

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03May2019

U-269

A-226

D-238

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Before/After	PRODUCT SUPPORT PROGRAM FOR REWORKING THE HYDRAULIC CABINET ON CERTAIN 794 AC, 796 AC, AND 798 AC OFF-HIGHWAY TRUCKS
4263 0679 7554		PS46254

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NOTE:

Caterpillar’s obligations under this Service Letter are subject to, and shall not apply in contravention of, the laws, rules, regulations, directives, ordinances, orders, or statutes of the United States, or of any other applicable jurisdiction, without recourse or liability with respect to Caterpillar.

NOTE:

This Program must be administered either before or after failure. In either case the decision whether to apply the Program is made by the dealer. When reporting the repair, use "PS46254" as the Part Number and "7755" as the Group Number. If administered before failure, use "56" as the Warranty Claim Description Code and "T" as the SIMS Description code. If administered after failure, use "96" as the Warranty Claim Description Code, and "Z" as the SIMS Description Code.

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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.

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TERMINATION DATE

31May2021

PROBLEM

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The existing brake accumulator mounting on the hydraulic cabinet and hydraulic cabinet mounting to the superstructure can fail on certain 794 AC, 796 AC, and 798 AC Off-Highway Trucks.

AFFECTED PRODUCT

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Model	Identification Number
794 AC	HRT00100, 102 MN500051-00056 MT500100-00143
796 AC	HRZ00500
798 AC	ST700400

PARTS NEEDED

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Qty	Part Number	Description
8	0S1591	BOLT-HEX HEAD
8	2K4973	LOCKNUT
8	5M2894	WASHER-HARD
16	6V7687	LOCKNUT (After Failure Only)
16	8T4223	WASHER-HARD
16	8T4648	BOLT-HEX HEAD
16	1511676	COLLAR
8	1984777	WASHER-HARD
2	2287090	SEAL-O-RING-ORFS
2	CHANNEL_001	DEALER FABRICATED
In order to allow equitable parts availability to all participating dealers, please limit your initial parts order to not exceed 32% of dealership population. This is an initial order recommendation only, and the ultimate responsibility for ordering the total number of parts needed to satisfy the program lies with the dealer.

ACTION REQUIRED

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Refer to the attached Rework Procedure.

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SERVICE CLAIM ALLOWANCES

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Product smu/age whichever comes first	Caterpillar		Dealer Suggested		Customer Suggested
Product smu/age whichever comes first	Parts %	Labor Hrs%	Parts %	Labor Hrs%	Parts %	Labor Hrs%
0-60000 hrs, 0-72 mo	100.0%	100.0%	0.0%	0.0%	0.0%	0.0%

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NOTE: This is a 6.0-hour job
This is a 6 hour job, including time required for disassembly, weld repair and reassembly. A maximum of $200 will be allowed for time and materials to fabricate two CHANNEL_001. An additional 2 hours will be allowed for a through thickness crack repair on the hydraulic cabinet if crack is present. A maximum of 5 hours will be allowed for all hydraulic cabinet crack repairs.

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PARTS DISPOSITION

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

Rework Procedure

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1. Fabricate two CHANNEL_001 (1). Cut 3" standard C Channel (refer to Image 1.1.1) to length (D) as shown in Image 1.1.2. Add hole (E) as shown in Image 1.1.3.

Image1.1.1

Image1.1.2

Image1.1.3

2. Disconnect hose assembly (H) and hose assembly (J) from brake accumulators.

Image1.2.1

3. Remove brake accumulators (K) and (L). Remove sixteen bolts (M), thirty-two washers (N), sixteen locknuts (P) and sixteen clamps (R). Save parts for reuse later.

Image1.3.1

4. Remove sixteen bolts (S) and sixteen washers (T). Remove two upper brackets (U) and two lower brackets (W). The bolts and washers will not be reused. Save brackets for reuse later.

Image1.4.1

5. Inspect backside plate of hydraulic cabinet for any cracks. On the opposite side of the plate inspect the plate area around the sixteen weldnuts (inside hydraulic cabinet) for any cracks. Any cracks found in plate must be repaired before a CHANNEL_001 (1) can be welded to plate.

NOTE: Reference PS46219 for a through thickness crack repair. If the plate area around a weldnut is cracked remove the weldnut. Weld up the through hole and blend and sand smooth to the surrounding plate on both sides of the plate. Re-drill 14 mm (0.55 inch) through hole.

6. Locate and weld two CHANNEL_001 (1) to backside of hydraulic cabinet with a 5 mm (0.20 inch) intermittent fillet weld on both sides of joint as shown in Images 1.1.2 and 1.1.3.

7. Assemble two upper brackets (U) and two lower brackets (W) that where removed in Step 4 to two CHANNEL_001 (1) using sixteen 151-1676 Spacers (2), sixteen 8T-4648 Bolts (3) and sixteen 8T-4223 Washers (4). Tighten bolts to 105 +/- 20 Nm (77 +/- 15 lb ft).

NOTE: With any new through hole that was re-drilled in Step 5, use a 8T-4223 Washer and 6V-7687 Locknut to secure 8T-4648 Bolt on the inside of the hydraulic cabinet.

Image1.7.1

8. Weld two upper brackets (U) and two lower brackets (W) to two CHANNEL_001 (1) with a 3 mm (0.12 inch) fillet weld on both sides of joint as shown in Image 1.8.1.

Image1.8.1

9. Assemble brake accumulators (K) and (L) to upper brackets (U) and lower brackets (W) using sixteen bolts (M), thirty-two washers (N), sixteen locknuts (P) and sixteen clamps (R) that were removed in Step 3. Tighten bolts to 105 +/- 20 Nm (77 +/- 15 lb ft).

10. Connect hose assembly (H) and hose assembly (J) to brake accumulators (K) and (L) using two 228-7090 O-Ring Seal (5). Tighten hose connections to 45 +/- 4 Nm (398 +/- 35 lb in).

11. Replace existing hydraulic cabinet mounting hardware with eight 0S-1591 Bolt (6), eight 198-4777 Washer (7), eight 5M-2894 Washer (8) and eight 2K-4973 Locknut (9). Tighten bolts to 47 +/- 9 Nm (35 +/- 7 lb ft).