Product Support Program For Installing A Suction Strainer On Certain CS433B And CP433B Vibratory Compactors 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 "PS0551" as Part Number, "7755" as Group Number, and "96" as Description Code

Termination Date

Problem

The priority check valve in the hydraulic system may become contaminated on certain CS433B and CP433B Vibratory Compactors. A contaminated priority check valve may cause the brake interlock to sense brake pressure lower than 350 psi and result in a lack of machine propel.

Affected Product
Model & Identification Number

CP433B, CS433B (1MG1-531)

Parts Needed

1 - 4C5300 Sealant

1 - 1G5614 Strainer

1 - 1G5615 Fitting

1 - 1G5621 Hose Assembly

2 - 4J5477 O-ring Seal

2 - 5K9090 O-ring Seal

1 - 2T2277 Hose Assembly

3 - 6V8400 O-ring Seal

1 - 6V9746 O-ring Seal

* - 7X5899 Cartridge (Use as required)

Action Required

See the attached rework procedure.

Service Claim Allowances

NOTE: This is a 10-hour job.

Parts Disposition

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

Attach. (1-Rework Procedure)

Rework Procedure

1. Check the brake system pressure at high idle. The pressure should be between 350 and 500 psi. If a pressure lower than 350 psi is observed, remove the priority check valve and inspect for debris or damage to the valve.

2. Drain oil from hydraulic tank to a level below the 7X5276 hydraulic tank manifold.

3. Remove 7X5713 Hose Assembly from the propel group and 7X5712 Hose Assembly from the steering group.

4. Remove 7X5276 Manifold from the hydraulic tank.

5. Install 1G5615 Fitting to inlet tube on hydraulic manifold as shown in Illustration 3. Follow the next steps to preset and install fitting.

a. Make sure the tube is cut squarely and deburr the end internally and externally.

b. Slip the nut and ferrule onto tube. Be sure that the long straight end of the ferrule points toward the end of the tube. See Illustration 1.

Illustration 1. Assembly of Ferulok Fitting

c. Lubricate the threads on fitting and both ends of ferrule with 2P2506 Thread Lube or an equivalent extreme friction lubricant.

d. Insert the tube into fitting until it bottoms against the shoulder of the fitting and tighten nut finger tight.

NOTE: It is necessary that tube is bottomed in the fitting or the ferrule will not crush into the tube correctly.

e. Tighten nut 1 turns to pre-set ferrule. Reliable assembly of all flareless fittings is dependent upon the ferrule traveling into the tube and achieving a positive grip and seal. Wrench torques (tightening specifications) should never be used as a guide for reliable assembly.

f. Inspect assembly using the pre-set instructions (See Page 4) to be sure the ferrule is formed to give a seal.

g. Insert the tube into the fitting body and tighten nut down easily until a sudden increase in torque is felt. Turn the nut an additional turn (one wrench flat) to again spring the ferrule into place to seal against tube and fitting body.

6. Install the 1G5614 Sump Strainer. The strainer must be positioned inside the hydraulic tank before installing the strainer to the fitting.

7. Apply 4C5300 Sealant liberally to the 7X5276 Manifold and install onto the hydraulic tank.

8. Install 2T2277 Hose Assembly as shown in Illustration 2. Install other components as shown in Illustaration 3. Note that the 1G5621 Hose Assembly and the 2T2277 Hose Assembly are mounted to the manifold in the reverse positions from the hose assemblies that were removed.

Illustration 2. New Hose Assembly for Propel Group

Illustration 3. New parts for Steering Group

9. Remove the 7X5899 Priority Cartridge and install a new 7X5899 Cartridge, if the cartridge is damaged.

10. Refill the hydraulic tank with hydraulic oil. Refer to the Operation and Maintenance Manual for the hydraulic oil specifications.

Pre-set Instructions:

1. Disassembly fitting body and nut to examine for correct crush on the tube.

Illustration 4. Pre-set Nomenclature

2. A ridge of metal has been raised above the tube surface to a height of at least 50% of the thickness of the leading edge of ferrule, completely around tube (A).

3. While the leading edge of ferrule may be coined (stamped) flat (B), there is a slight bow to the balance of the pilot section (C).

4. The tail or back end of the ferrule is snug against the tube (D).

5. There is a slight indentation all around the end of the tube (E) that indicates the tube was bottomed in the fitting during the pre-setting step. There must be visible evidence of this complete contact before the ferrule can be correctly pre-set.

6. The ferrule may be rotated on the tube, but should not be capable of moving back and forth along the tube beyond the bite area. When rotated turn, there should never be an uneven gap between ferrule and the bite.