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Q. What is involved in repairing a cylinder?
A. Simply put, a lot. All cylinders are pressure washed and cleaned externally before entering our facility. Then they are set up in special horizontal vises and completely drained of oil. Depending on design, heads and end caps are marked for port orientation. From here the cylinder is dismantled and sent to our inspection area. Once ready for inspection, individual parts are set up and measured with micrometers to check bore to piston and rod to gland tolerance. Rods are checked for straightness and honing stones are run through barrel to determine concentricity. Most hard parts are made in our machine shop using raw material from stock while soft seals are pulled from inventory or supplied by other vendors such as OEM seal kits. After all work is complete the cylinder goes to our assembly area where again it is washed, assembled, pressure tested, and sent to the paint room.

Q. How long does it take to repair a cylinder?
A. This depends entirely on what has to be done to repair it. The only way to answer this would be to dismantle and inspect all the components and check parts availability. The assumption that all parts are good and seals are readily available generally leads to surprises and disappointment later on.

Q. What does it cost to repair an average size cylinder?
A. Repair costs is not based on the size of cylinder. Small cylinders can require more work to be performed or large cylinders may require less. Once a cylinder is apart, inspected, and parts researched a repair cost estimate can them be reached.

Q. My cylinder was working fine it was just leaking. Can't you just replace the seals?
A. Yes. Although replacing seals may not correct the problem. The working fine part is not the reason you want to repair the cylinder; it's the leaking part. We want to determine the reason it's leaking. Many times rods are slightly bent causing wear in gland assembly. Replacing seals will stop the leak for a while, but is not a permanent solution.

Q. I was told my cylinder had metal in the fluid. What does this mean?
A. Serious problems exist when metal is found in any system. Cylinders can experience misalignment causing a side load that would result in bearing failure or a pump could be failing. The only way metal contamination can be removed is to flush the entire system. Changing filters will not correct the problem it only gives a false sense of security. The tank must be drained, hoses, cylinders, motors and steel lines must be removed, cleaned and installed. It is an expensive and time consuming process.

Q. How can I prevent contamination in my hydraulic system?
A. Hydraulic components are moving metal parts that over time will wear. Aside form a catastrophic failure, prevention is the only method. Take steps to keep all components clean and free from heavy accumulation of grease and dirt. Grease will retain heat and attract dust. Rubber hoses and seals deteriorate as does condensation forms in most equipment over time. Keep filters changed regularly and keep oil temperatures at or below 180 degrees.

Q. What is an NFPA interchangeable cylinder?
A. NFPA stands for National Fluid Power Association. This organization set up standards for all manufacturers of the tie rod design. Mounting codes were established to ensure that all cylinders of different brands would dimensionally interchange. Where NFPA cylinder manufacturers differentiate themselves are their internal designs. In other words, an MP1 mounting of one brand is the same external dimensions as a different brand. Because of design changes, a seal kit from one cylinder will not interchange with another.

Copyright 2013 Five Rivers Hyd

5 Rivers Hydraulics | 1006 W. Old Andrew Johnson Hwy., New Market, TN 37820 | Phone:  865.475.4731

Copyright 2006 Five Rivers Hydraulics, Inc.

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