Disassembling a hydraulic cylinder must always be done using the proper tools. Here’s our quick guide to safe cylinder disassembly.
The number one rule when disassembling a hydraulic cylinder is safety. At a minimum, you must wear safety glasses and steel-capped boots. Make absolutely sure there is no residual load on the cylinder to prevent oil from discharging unexpectedly during disassembly.
Start by visually inspecting the cylinder and rod for any obvious signs of damage. If possible, loosen the oil plugs or bleed screws early on to allow most of the oil to drain out.
Secure the cylinder firmly in a bench to ensure safe handling. For longer cylinders, it’s recommended to place a support under the rod guide end to keep everything stable.
Disassembly begins by identifying how the seal housing or rod guide is fixed to the cylinder tube. Common attachment methods include retaining threads, locking screws, or adhesives.
It’s worth confirming the fastening method before applying force—you’ll avoid unnecessary damage and frustration. In many cases, gentle heating may help release tight components. You can also try lightly tapping around the threaded area with a soft-faced hammer, which often helps loosen the thread.
When removing the guide, always use the correct tools. These include, but are not limited to:
Hook spanner
Pin spanner
Soft-faced hammer (e.g. machinist’s hammer)
Container for waste oil
As you begin to loosen the rod guide, oil will often start to leak from the cylinder. Always make sure there is a suitable container placed underneath to catch the oil and prevent spills.
Once the rod guide is removed, the rod, guide, and piston can be pulled out as a single assembly. Keep in mind that residual oil may still be inside the cylinder, and moving the rod back and forth can cause it to spray out under pressure—handle with care.
After the rod assembly is removed, the cylinder tube can also be taken off. At this point, it’s important to inspect the internal surface of the tube. Use a torch to carefully examine the surface visually, and also run your fingers along the inside to check for dents, grooves, or other damage.
Next, secure the rod in a press to remove the piston. Before loosening anything, check carefully for locking screws or pins that may be securing the piston in place. These are often marked with a punch near the screw head. If needed, you can clean or drill out the punch mark to access the screw.
Once any locking components are cleared, use the appropriate pliers or spanner to unscrew the piston from the rod.
After that, the seal housing can be pulled off, and the rod can be released from the bench.
