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.