Hydraulic Cylinder Rebuild: When a Seal Kit Is Not Enough

A proper hydraulic cylinder rebuild begins with complete disassembly, cleaning and inspection. The condition of the rod, barrel, piston, gland, wear bands and sealing surfaces all affects whether the cylinder will operate correctly after it is reassembled.

Common cylinder problems include:

• External oil leaks
• Internal bypass and drifting
• Weak or uneven movement
• Bent or damaged rods
• Scratched or pitted chrome
• Scored cylinder barrels
• Worn bushings, pins or mounting points
• Contamination inside the hydraulic system

New seals cannot compensate for a bent rod, damaged chrome or an excessively worn barrel. If those underlying conditions are not corrected, the new seals may begin leaking again or the cylinder may continue bypassing internally.

Seal identification is also important. Hydraulic cylinders can use different seal materials and profiles depending on their operating pressure, temperature, fluid and application. The replacement seals must fit the cylinder and its working environment, not simply look similar to the originals.

After inspection, the correct repair may include resealing, honing, rod repair or replacement, machining, wear-component replacement or other corrective work. The cylinder should then be assembled carefully, lubricated properly and checked for correct operation and leakage.

Mondak Equipment & Hose evaluates the complete cylinder instead of treating every failure as a simple seal-kit job. We also look for equipment-side problems that may have contributed to the failure, including contamination, excessive pressure, damaged mounting points and side loading.

If a hydraulic cylinder is leaking, drifting or no longer producing the force it should, contact Mondak Equipment & Hose. We provide hydraulic cylinder and equipment repair for customers throughout western North Dakota and eastern Montana.