HYDRAULIC CYLINDERS
There different types of hydraulic cylinder repairs:
Piston seal:
The piston seal can become defective if it is distorted, eroded or missing and this is usually a cause of an oversized barrel or bulge during operation.
At this point, replacement of the barrel or cylinder is required. If you replace the piston seal only and not the barrel, whilst this is a quicker method of repair, it is a short-term fix. More maintenance would be required later on.
Rod seal:
A distorted rod seal can be caused by excessive wear of the guide bush or if the rod is bent.
The consequence of this is the rod weight pushing on the seal, causing failure.
If you replace the rod seal without identifying and correcting the underlying issues, then again, the fix will only be short-term.
Rod:
In most cases, the chrome on the rod can be inspected and if it is shiny on one side and dull on the other, the rod is bent.
The straightness of the rod should always be checked when repairing the cylinder. Bent rods can be corrected by using a press.
Whilst it is possible to prevent damage to the hard-chrome plating during this process,
if the chrome is spoiled, it must either be re-chromed or the entire cylinder must be replaced.
A damaged chrome surface decreases the efficiency and service life of the rod seals.
If the rod only has some minor scratches, they can be polished out using fine emery paper.
Piston:
In light-duty applications, pistons within the cylinders are designed with aluminum or cast iron, and are in constant direct contact with the cylinder bore whilst in operation.
Some scratching on the outer surface of the piston poses no risk to the cylinder’s function, as long as the nominal bore diameter does not exceed the minimum diameter of the piston.
A good tool to use to check the length could be a micrometer.
Our hydraulic cylinder repair service:
A hydraulic cylinder repair is a relatively simple process, as they are less complex than other hydraulic components;
In many cases a well-repaired cylinder is indistinguishable from a brand new unit. We offer a hydraulic cylinder repair service, in addition to repairs on pumps, motors, power packs and other types of hydraulic equipment.
Internal and external leaking is the most common reason for repairs on hydraulic cylinders.
But, by disassembling and closely inspecting the damage to the cylinder, you may be able to see other problems that aren’t immediately obvious
We may conclude that a repair is not viable, or that your repaired equipment may be unreliable or prone to poor performance in future.
If this is the case then we will always contact you to explain why and
to quote for a replacement new unit so that you can choose what you want to do.
Hydraulic Cylinder Testing:
- Ensure the cylinder is secured so that it is controlled;
- Clean hydraulic fluid must fill both sides of the cylinder – do this through the service ports;
- Connect all components – directional control valve, relief valve, ball valves and gauges;
- Remove any air from the cylinder by using the directional control valve and stroking the cylinder numerous times;
- Place the piston rod mid-stroke and close the ball valve;
- Direct the fluid flow to the side of the cylinder where the rod is located;
- Increase the setting on the relief valve until the pressure of the cylinder is seen on the gauge;
- Close both the ball valve and the directional control valve;
- Record the pressure of the cylinder from on both gauges and keep an eye on any changes
