Hydraulic Cylinder Repair

Hydraulic RAM Repairs UK offer comprehensive repair service for Hydraulic Cylinders.

Following arrival at our Mitcham workshops, we closely examine all parts of the hydraulic cylinder after disassembly, especially the hydraulic seals, as this may reveal problems that may not otherwise be apparent.

The pistons of hydraulic cylinders used in light-duty applications are usually machined from aluminum alloy or cast iron and operate in direct contact with the cylinder bore. Minor scoring on the outside diameter of the piston is not detrimental to the function of the hydraulic cylinder, as long as the minimum diameter of the piston is not less than the nominal bore diameter minus 0.006”. This can be checked using an external micrometer.  If the piston diameter measures outside the accepted tolerance, we recommend it is replaced with a new piston, machined from a similar material.

Non-metallic wear bands are fitted between the piston and barrel, in applications where there are high loads on the rod.  If the cylinder is fitted with piston wear bands, Hydraulic RAM Repairs UK recommend these should be replaced as part of the repair.

In many cases the pump may be the root cause of the problem. However, more commonly the usual problems arise from faulty seals in the cylinder itself. After determining the cylinder is not damaged by swelling or by being cracked and the piston rod is not bent itself, replacing the seals and piston rings is a straight forward task.

The seal around the shaft itself is often the culprit and the entire assembly must be dismantled to replace this item. We also recommend that at the same time the cylinder seals are replaced. Not to do so is false economy.

Before starting to disassemble the hydraulic cylinder we clearly identify all the relevant parts to ensure successful re-assembly and testing. Although most hydraulic cylinders are often a few feet long, extreme caution is practiced by us when repairing large or heavy cylinders, in particular single action type.

Finally, we carefully clean all parts in a petroleum-based solvent and blow-dry using compressed air. Coat all parts with clean hydraulic fluid during assembly. Prior to installing seals, we ensure that the seal grooves are clean and free from nicks and burrs.  Special care is taken by us when we install seals, as this can result in damage to the seal. After the cylinder has been assembled, we plug its service ports to prevent ingress of moisture or dirt.   All the hydraulic cylinder repair work is carried out in a special ‘clean room’ at the Mitcham workshops of Hydraulic RAM Repairs UK Ltd.