Hydraulic cylinder repair seals and kits-Hercules Sealing Products - Hydraulic Seals and replacement cylinders for construction and many other heavy equipment industries. Hercules Sealing Products is a distributor of hydraulic and pneumatic cylinder repair seals, seal kits and repair parts, engine and transmission gaskets, and replacement cylinders for all heavy equipment brands. Premium replacement engine and transmission gasket kits are also available for popular off road and marine applications. We are stocked for well-known brands such as Caterpillar, Case, John Deere, Komatsu, Hitachi, Toyota, Volvo and many more. The company's primary repair industries... Hercules Hydraulic Seals - Hercules has a wide selection of hydraulic repair parts for 150+ brands such as Caterpillar®, John Deere®, Komatsu®, Case®, Volvo®.