These cylinders typically fail first in the rear of the cylinder. The OEM (Original Equipment Manufacturer) cylinders have front and rear caps that are sealed from the cylinder bodies with a seal material that decays over time.

Top Hydraulics replaces those seals with a far superior material that is not sensitive to water and is resistant to most additives in hydraulic fluid. Our seals have a larger cross section for a superior static seal. The OEM cylinders rely on a tiny o-ring to energize a very thin, flat rod seal. The o-rings loose elasticity over time, and the OEM rod seals wear out.

Top Hydraulics manufactures and installs its own precision CNC machined front caps in these cylinders, so that the tiny OEM rod seals can be replaced with Top Hydraulics' own u-cup seals for a far more reliable seal and much longer service life. In addition, the size and geometry of Top Hydraulics' u-cups is forgiving to tiny scratches and imperfections in the cylinder rods (aka piston rods or shafts), caused during the original manufacture, during removal from the car, during installation into the car, or by impurities in the hydraulic fluid.

Top Hydraulics replaces the port seals (where the hydraulic hoses attach) and ships spares with each cylinder, in case your mechanic accidentally pinches an o-ring while installing the hydraulic hose.

Owning and driving a convertible with an automatic top is prestigious, convenient and exciting - let Top Hydraulics help you enjoy your beautiful car even more by making your convertible top system truly better than new!.

Our Core Exchange option makes this as easy as buying a new cylinder - you only have to ship back your old cylinder(s) afterwards for core credit.

Top Hydraulics' also rebuilds and upgrades convertible hydraulic pumps, as well as manufacturing our own upgraded hydraulic lines.

Top Hydraulics' standard warranty is 3 years on rebuilds/upgrades of convertible top cylinders and hydraulic pumps, and on new hydraulic hoses.