The Steering System Needs To Be Modified On Certain 789B Trucks Caterpillar

The Steering System Needs To Be Modified On Certain 789B Trucks

Usage:

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Caterpillar: Confidential Yellow

NOTE: This Program must be administered as soon as possible.When reporting the repair,use "PI1226" as the Part Number,"7751"as the Group Number, "56"as the Warranty Claim Description Code and "T " as the SIMS Description Code.Exception:If the repair is done after failure,use "PI1226"as the Part Number,"7751"as the Group Number, "96"as the Warranty Claim Description Code,and"Z "as the SIMS Description Code.

Problem

Rapid pressure signals might occur in the steering system of certain 789B Trucks.This could cause internal damage to the compensator valve,fast and frequent cycling of the steering pump, or breakage of a hose stem within the steering lines.

Affected Product
Model & Identification Number

789B7EK1-153,7EK162,7EK164-167

Parts Needed

Dealers will need to order parts for this Program.

1 - 1A2029 Capscrew

1 - 3E7432 Elbow

6 - 3J1907 Seal

1 - 4J0522 Seal-O-Ring

1 - 5M2894 Washer

1 - 5P7462 Clip

1 - 5P7463 Clip

1 - 1T0936 Plug

2 - 8T4205 Washer

1 - 8T7876 Seal-O-Ring

1 - 6V0683 Grommet

8 - 6V8397 Seal

1 - 6V8636 Connector

3 - 6V8724 Elbow

1 - 6V8774 Tee

1 - 6V8926 Adapter

* -8W1551 Bar (Fabricated)

2 - 7X0264 Bolt

4 - 7X0312 Bolt

* -8X9627 Hose Assembly (Fabricated)

* -8X9628 Hose Assembly (Fabricated)

* -8X9629 Hose Assembly (Fabricated)

* -8X9630 Hose Assembly (Fabricated)

1 - 8X9631 Adapter

1 -1004181 Valve Group(If Required)

1 -1078137 Valve Group

1 -1082184 Valve Group

*The dealer is to fabricate all of the hose assemblies required.One hose assembly of each part number will be required

Action Required

See the attached procedure.

Owner Notification

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

Service Claim Allowances

NOTE: This is a 6-hour job.

NOTE: U.S. and Canadian Dealers Only - Eligible dealers may enter a Type 2 SIMS Report.

Parts Disposition

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

NOTE: MAKE EVERY EFFORT TO COMPLETE THIS PROGRAM AS SOON AS POSSIBLE.

Attach.

(1-Owner Notification)

(2-Rework Procedure)

Copy Of Owner Notification For U.S. and Canadian Owners

Rework Procedure

NOTE: All directions given are vehicle left and vehicle right as the operator is sitting in the cab.

NOTE: Fabricate one 8W1551 Bar prior to beginning rework.

Steering Pump

1. Remove 7I5506 Hose Assembly from the 101-0717 Valve Group (unloading) on the pump between the compensator and body.

2. Remove the four 6V8213 Bolts which connect 100-4181 Valve Group (compensator) and 101-0717 valve group (unloading) to steering pump.

3. Disconnect 101-0716 Tube Assembly that connects the compensator to the unloading valve and remove with 6E6628 Valve Group. Also, remove all fittings at both ends of the tube.

4. Inspect the 100-4181 Valve Group for internal wear to spools or to body. If any wear is evident, replace the valve.

5. Using four 6V8337 Bolts, mount the 100-4181 Valve Group directly to the pump.

6. Install 6V8774 Tee with 3J1907 Seal in open port (where tube was removed) of compensator valve.

7. Remove plug from top port of pump and install 6V8926 Adaptor, 3E7432 Elbow, and 1T0936 Plug using 8T7876 Seal, 6V8397 Seal, and 3J1907Seal. (The 1T0936 Plug threads into the 3E7432 Elbow.)

8. Connect 8X9630 Hose Assembly to fittings in tee and in top of pump using two 6V8397 Seals.

9. Connect 8X9629 Hose Assembly to straight end of tee using 6V8397 Seal.

Front Of Suspension Support Casting (right)

1. On right side (6E6298 Main Relief Valve Block) remove four 7X0310 Bolts and disconnect 8W3802 Hose Assembly from 6D0837 Elbow. Add 8X9631 Adapter with 4J0522 Sealand connect the hose with four 7X0312 Bolts.

2. Into port on front of adapter, screw one 6V8724 Elbow with one 3J1907 Seal.

3. Connect one end of 8X9627 Hose Assembly with one 6V8397 Seal to 6V8724 Elbow.

4. Remove 7I5506 Hose Assembly from 8T2882 Tee on top of relief valve block.

5. Connect the 90 degree bend end of 8X9628 Hose Assembly to existing 8T2883 Tee using 6V8397 Seal.

Front Of Suspension Support Casting (Left)

1. Weld the fabricated 8W1551 Bar to front of steering box (between suspension support castings) 250 mm to right of existing steering valves and 70 mm below bottom of engine oil pan.(See Illustration1)

2. Mount 107-8137 Valve Group (unloading) to 8W1551 Bar using two 7X0264 Bolts and two 8T4205 Washers. Mount valve with stem to left and tag toward front of truck.

3. In right side of unloading valve, connect 8X9628 Hose Assembly using 6V8397 Seal, 6V8636 Connector, and 3J1907 Seal.

4. In top of unloading valve, connect 8X9627 Hose Assembly using 6V8397 Seal, 6V8724 Elbow, and 3J1907 Seal.

5. In bottom of unloading valve, connect 8X9629 Hose Assembly using 6V8397 Seal, 6V8724 Elbow, and 3J1907 Seal.

6. Using 5P7462 Clip, 5P7463 Clip, 1A2029 Bolt, 5M2894 Washer, and 6V0683 Grommet, secure the 8X9629 Hose Assembly to the front of the right suspension support casting at the boss just to the left of the main relief valve. Adjust the hose to eliminate interference.