Dipper ram seal kit JS 903/20265 JCB JS, aftermarket

For the JCB JS crawler excavators: dipper ram seal kit JS 903/20265, an aftermarket part. According to the product card, the kit is for the dipper cylinder of a JS excavator.

When the seals are changed, the cylinder's metal parts must be inspected. Scratches, rust or flaking chrome on the rod will soon cut a new rod seal, and scoring in the bore will spoil the piston seal. If the rod is bent or the bushes are worn, the seals are loaded on one side and wear early. Such damage is put right together with the seal change.

Specifications

Compatibility

According to the product card, 903/20265 is a hydraulic cylinder seal kit. Fit is confirmed by the part number. Other parts are in Repair kits.

Fitting

No sharp tools are used when fitting the seals: fold the seal slightly into a kidney shape, insert it in the groove and ease it into place by hand. Fit the rod seal and wiper in the gland grooves the right way round, as a reversed seal leaks at once under pressure. Cover the rod threads and edges with a thin protective sleeve or tape as they pass through the gland. After assembly, test the cylinder first without load, then under load, and check the seal area again after a day's work. After the first working day, grease the cylinder mounting pins and check the rod for any trace of oil.