- Caterpillar Products: All
This instruction gives the procedure for installing seals in the head of hydraulic cylinders. There are three seals in this kit. The three seals are one vented buffer seal assembly, one U-cup seal, and one double lip wiper seal.
Installation of the Seals
- Install vented buffer seal assembly (1). The seal assembly consists of one seal (1A) and one backup ring (1B) .
- Install vented buffer seal (1A) in the correct groove of cylinder head (4). Seal (1) has a groove for backup ring (1B). The groove must face the rod end of the cylinder. Refer to Illustration 1 for the correct assembly position.
- Install backup ring (1B) in seal (1A). Refer to Illustration 1 for the correct assembly position.
- Install the U-Cup seal (2) in head (4). Install the seal with the open end of the "U" facing toward the piston end of the cylinder. Refer to Illustration 1 for the correct assembly position.
- Use sandpaper or emery cloth to scuff the surfaces of the counterbore in the cylinder head and the outside diameter (3A) of the wiper seal's metal shell.
- Clean the counterbore in the head and the outside diameter (3A) of the wiper seal's metal shell with 8T-9011 Component Cleaner or 6V-1541 Quick Cure Primer . Clean the counterbore and the metal shell until neither of the components discolor a clean white towel.
Note: 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 counterbore or the metal shell because the oil from your fingers may prevent a good bond. Handle the seal by the lip only.
- 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.
- Apply 7M-7456 Bearing Mount Compound evenly but do not apply the compound excessively. Apply the compound to the counterbore and to the metal shell. Do NOT allow the compound to contact the sealing lip.
- Install double lip wiper seal (3) into the cylinder head. Refer to surface (3B) in order to make sure that the marking "THIS SIDE OUT" on the seal is toward the rod end. Refer to Illustration 1 for the correct assembly position. The seal should be firmly seated against the bottom of the counterbore. Wipe away any excess bearing mount compound. Allow the compound to dry for 15 minutes before assembling the hydraulic cylinder.
- Lightly lubricate the seals with clean hydraulic fluid before installing the head on the cylinder rod.