We upgrade your cylinder(s) by replacing the tiny OEM rod seal with a much larger one made of superior materials. We then add custom caps made of CNC machined stainless steel to accommodate these superior seals. Our seals are not sensitive to water and are resistant to most additives in hydraulic fluid. This results in a much longer service life than the standard OEM cylinders for a fraction of the price.
Top Hydraulics' also rebuilds and upgrades convertible hydraulic pumps, and we also manufacture 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.
You remove your cylinders you would like to have rebuilt, and send them to us.
Core Exchange is currently NOT available for Bentley cylinders.
The Bentley Azure has 12 cylinders. They should be upgraded at least in pairs, and preferably as a complete set. Once we receive your cylinders, the turn around time for Bentley cylinders is up to two days for rebuild service and we will ship the cylinders back to you by Priority U.S. Mail (2-3 days delivery time). Please note that in the unlikely event the brass colored main lift cylinders or tonneau cover lift cylinders should have rust on the chromed shafts, we will have to replace the chromed shafts with stainless steel ones of our own manufacture for a surcharge.
Bentley Azures use some Mercedes "R129" cylinders, with two of them modified. Rebuilding these cylinders is NOT a matter of changing o-rings. Every R129 cylinder has one o-ring, and those rarely ever fail. What fails most frequently, are the other seals, which have special shapes for proper function. Top Hydraulics replaces and upgrades ALL seals in the cylinders with superior materials:
1) Rod seals. They are cup-shaped and seal the piston rod from the rest of the cylinder. When they fail, you will see fluid coming out next to the chromed shaft (rod). These are usually the first seals to fail in the cylinders.
2) Piston seals. They seal the input and output sections from each other, as the piston slides through the cylinder. The piston seals have been made of different materials and sizes even in the same p/n cylinders throughout the years. Failing piston seals will cause internal leaks, which result in a pressure drop in your hydraulic system. Early model years have the added problem that the piston seals swell up and make it very hard to move the piston inside the cylinder. Crumbling piston seals can block valves or pinholes inside the hydraulic system, and it can be difficult to diagnose a piston seal failure without testing several cylinders once you find that your top is moving slowly or not at all.
3) Cap seals. These are just o-rings that seal the top cap of the cylinder from the housing. They are usually the last seals to fail, but these o-rings are penny items.
4) Port seals. They seal the hydraulic lines where they are pushed into the cylinders. Port seal failure is becoming more and more common as the R129s age. It also applies to the front distributor p/n 1298000022. Port seals have a special shape that makes them seal under pressure. O-rings wouldn't do the trick. They are secured by precisely machined brass rings (accuracy about 1/100 mm). DIY removal of the brass rings will almost certainly destroy the brass rings. Top Hydraulics installs port seals that are tighter than the originals, just in case the hydraulic line fittings have been scratched.
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!