Hydraulic cylinder seal kit 338-7156 CAT, aftermarket

Hydraulic cylinder seal kit 338-7156 is an aftermarket part for the Caterpillar machines.

Seals are replaced as a set: renewing only the leaking one means the other old, hardened seals soon leak too. The kit's seals are made of different materials such as polyurethane, NBR rubber and PTFE, each chosen for where it works. Store the kit somewhere cool and dark in its packaging and inspect the parts before use.

Specifications

Compatibility

According to the product card, Caterpillar 338-7156 is a hydraulic cylinder seal kit. Fit is confirmed by the cylinder or kit part number. Other parts are in Repair kits.

Fitting

Before the repair, disconnect the cylinder from the hydraulics, release the pressure and clean it outside, then dismantle it on a clean bench. Remove the old seals with plastic or brass tools so the grooves are not scratched. Wet the new seals with clean hydraulic oil and fit them the right way round; piston seals can be softened in warm oil if needed and sized with a calibrating sleeve. Pass the rod through the gland without damaging the seal and tighten the piston nut to the specified torque. After assembly, cycle the cylinder through full strokes a few times without load to purge air and check for leaks.