Incorrect Assembly Instructions For Rod Seals In Hydraulic Cylinders Caterpillar

ARTICULATED TRUCKS

BACKHOE LOADERS

EXCAVATORS

MINI-HYDRAULIC EXCAVATORS

OFF-HIGHWAY TRUCKS

OFF-HIGHWY TRACTORS

TRACK-TYPE LOADERS

TRACK-TYPE TRACTORS

UNDERGROUND ARTICULATED TRUCKS

TRACK-TYPE SKIDDERS

WHEEL SKIDDERS

SKID STEER LOADERS

MOTOR GRADERS

EARTHMOVING COMPACTORS

SOIL STABILIZER

ASPHALT PAVERS

COLD PLANERS

SOIL COMPACTORS

PIPELAYERS

ROAD RECLAIMERS

PAVING COMPACTORS

LANDFILL COMPACTORS

WHEEL LOADERS

WHEEL TRACTORS

COMPACT WHEEL LOADERS

TELEHANDLERS

INTEGRATED TOOLCARRIERS

FOREST PRODUCTS

WHEEL TRACTOR SCRAPER

Problem:

During the period between April 2000 and October 2000, some seal kits for hydraulic cylinders were packaged with incorrect assembly instructions. The seal kits contained the new yellow colored Caterpillar rod seals. The instructions that were included with the kit contained information for the old seals. The older instructions will lead to incorrect installation of the new seals. The new seals can be recognized by the yellow color. The new seals also have a wiper seal with a flat face.

Pay close attention to the correct position of the backup ring for the buffer seal. This backup ring should face toward the rod end of the cylinder. The following instructions are the correct instructions.

Solution:

1. Refer to the illustration in order to install the polyurethane buffer seal (1) in the inner groove of the cylinder head.

2. Install the backup ring (2) for the buffer seal in the inner groove on top of plyurethane buffer seal (1). The backup ring for the buffer seal should face toward the rod end.

3. Install the U-Cup seal (3) in the head. Install the seal with the open end of the "U" facing toward the piston end of the cylinder.

4. Use sandpaper or emery cloth in order to scuff the surfaces of the counterbore in the cylinder head and the outside diameter of the wiper seal's metal shell (4).

5. Clean the counterbore in the head and the outside diameter of the wiper seal's metal shell with 8T-9011 Compound Cleaner or 6V- Quick Cure Primer. Clean the counterbore and the metal shell until neither of the components discolor a clean white towel.

The metal shell of the wiper seal is coated with a corrosion inhibitor. This may prevent proper bonding of the wiper seal to the cylinder head if the inhibitor is not removed. After cleaning, do not touch the counter bore or the metal shell because the oil from your fingers may prevent a good bond. Handle the seal by the lip only

6. Apply 6V-1541 Quick Cure Primer on the counterbore and the metal shell. Allow the primer to dry. The primer will dry in approximately 30 seconds.

7. Apply 7M-7456 Bearing Mount Compound evenly but do not apply the compound excessively. Apply the compound to the counter bore and the metal shell. Do NOT allow the compound to contact the sealing lip.

8. Press the wiper seal (4) into the cylinder head. Refer to item (B) in order to make sure that the marking "THIS SIDE OUT" on the seal is toward the rod end. This seal should be firmly seated against the bottom of the counterbore. Wipe away any excess Bearing Marking Coumpound. Allow the compound to dry for 15 minutes before assembling the hydraulic cylinder.

9. Lightly lubricate the seals with clean hycraulic fluid before installing the head of the cylinder rod.

COPYRIGHT 2001 CATERPILLAR ALL RIGHTS RESERVED