Copyright Goodheart-Willcox Co., Inc.
Chapter 6 Cylinders 137
A gland contains an internal wear ring that prevents the cylinder rod from
rubbing on the gland. An external O-ring seal is also located on the threads of
the gland. This static seal prevents leakage between the gland and the barrel.
Barrel
After a gland has been removed, the barrel can be honed. A Flex-Hone® is
an attachment placed on a lathe or a drill and is used to machine the inside
surface of the barrel. See Figure 6-19. The hone deglazes the surface removing
rust and small blemishes. If a cylinder is rebuilt and not honed, it is possible
that the piston seals will leak because the barrel’s surface is too slick. The hones
are offered in eight different material compositions. One of the most popular
hones used for hydraulic cylinders is made of silicon-carbide.
Cylinder housings vary in design. Some cylinders cannot be rebuilt, because
they are welded together from the factory. A tie bolt cylinder is designed to be
repairable. The housing contains four long bolts that mate the rod end with the
cap end. See Figure 6-20. These cylinders are commonly found on agricultural
implements. The cylinders can be easier to rebuild and contain an O-ring seal
between the cylinder’s barrel and the end plates. The cylinders are also known
as tie rod cylinders.
Figure 6-19. A Flex-Hone is used to machine the inside surface of a cylinder’s barrel. The hone deglazes the
cylinder’s surface while removing rust and small blemishes.
Figure 6-20. A tie bolt cylinder uses four long bolts to clamp the cylinder’s end caps to the barrel. The cylinder can be
easier to rebuild.
Tie bolts