Remove the wear ring, O-ring, and backup ring
from the outside of the head and the wear rings,
buffer seal, deep Z rod seal, and wiper ring from the
Do not damage the O-rings during
inside of the head.
installation of the check valve. If the
check valve turns freely then gets hard to
If necessary, remove the pilot-operated check
turn, then easy to turn; remove the check
valve from the port block.
valve and check the O-rings. They have
probably been damaged by a sharp
edge of a port.
Clean all parts with solvent and dry with
compressed air. Inspect all parts for serviceability.
The check valve should turn by hand
until compression of the O-rings begins.
Before installing new seals and rings,
Carefully install the check valve into the port
clean all surfaces and carefully remove
block until fully seated.
burrs and nicks.
excessive wear or damage should be
When installing new seals and rings,
avoid stretching the seals or scratching
Stone out minor blemishes and polish with a
the grooved and gland surfaces.
fine crocus cloth.
Clean with solvent and dry with compressed
air any parts that have been stoned and polished.
Lubricate new seals and rings with clean
Inspect the barrel carefully for scoring.
Locate the gap of each wear ring 180
degrees with respect to each other.
Steps 1, 2, 3, and 4 are used only if the
Install the wear rings into the head.
check valve has been removed.
Check the inside of the port block for any
sharp edges or burrs and remove as necessary with
Install new O-rings onto the check valve, refer
Lubricate the check valve and O-rings with
clean hydraulic oil.