What are the most common parts needed to repair a hydraulic jack?

The parts needed to repair a hydraulic jack are the cylinder and the pump plunger. These parts contain seals and check-balls that need to function well.

In the past, the seals were made from leather and rope packing. Nowadays, some manufacturers still use leather, but it is typically replaced with polyurethane and neoprene. When working with these parts, it's important to avoid exposing the seals to fire, heat, alcohol, chemicals or acid to prevent damage and to extend the life of the hydraulic jack. If the components are not repaired properly, the jack will not hold the weight, and his can cause it to fall.