Procedure to Inspect and Test Scratches on the Cylinder Rod Is Available on Certain 420F and 420F2 Backhoe Loaders Shipped to South America {5102, 5104, 5105, 5362, 5456, 5457, 5458, 5468, 5486} Caterpillar

Backhoe Loader

420F (S/N: LTG1-UP)

420F2 (S/N: LBS1-UP)

420F2 ST (S/N: LYB1-UP)

Reference: Special Instruction , SEHS9031 , "Storage Procedure for Caterpillar Products".

Reference: Special Instruction , SEBF8072 , "Reuse And Salvage Guidelines".

Reference: Technical Analysis , SEHS0531 , "Drift Check for the Loader Cylinders, Backhoe Cylinders, and Stabilizer Cylinders ".

A procedure to inspect and test scratches on the cylinder rod is available on the machines listed above. Superficial linear scratches on the cylinder rods are not detrimental to rod seal performance.

Illustration 1	g06228493
Scratch on the cylinder rod

Illustration 2	g06229948
Scratch on the cylinder rod

Superficial linear scratches on the cylinder rods as shown in Illustration 1 and Illustration 2 are not detrimental to rod seal performance since the storage inspection has been followed. For information regarding the storage procedure refer to Special Instruction, SEHS9031, "Storage Procedure For Caterpillar Products".

Procedure for Hydraulic Cycle Inspection

Follow the procedure below for hydraulic cycle inspection.

1. During this process ensure that the engine is in NEUTRAL and the parking brake is engaged.

2. Set the engine to 1600 ± 100rpm and perform boom down over the locks for five minutes to heat the hydraulic oil.

3. Cycle all cylinders five times at 1600rpm (including loader arm).

4. Cycle all cylinders five times at high idle (including loader arm).

Note: A cycle is defined as moving the cylinder from a fully extended position to a fully retracted position and back again. Remove the swing pin and cycle the swing cylinders without hitting the frame with the swing casting. The boom is cycled from a fully raised position until the bucket/stick linkage reaches the ground. Stall the functions at the end of each cylinder stroke.

Procedure for Drift Test and Inspection

Inspect the cylinder rod for any drift or leaks. If any drift or leak is found, follow the procedure below.

Illustration 3	g06229950
(A) 300.0 mm (11.81 inch)

1. Raise the machine with the front loader and the stabilizer legs above the ground to the dimension (A) as shown in Illustration 3. Extend all functions (see notes) and release all levers to NEUTRAL position and shut off the engine with electrical on. Let the machine sit for five minutes.

2. Check the machine for any significant drift in any implements.

Note: The front loader bucket must be positioned in the dump position with the machine weight on the bucket edge. The boom should be lowered, the stick extended and the bucket at full dump. If installed, the e-stick must be partially extended. If there is significant drift cycle, the function must be retested five times at 1600rpm. If it continues to fail, then report. During the drift test, walk around the machine and check for any leaks, sharp edges on the frame and hose routings.

Monitor the machine drift performance regularly to avoid operational issues in the field. For technical inspection (Drift Check) refer to "Technical Analysis" SEHS0531.