HY13-1597-01/US
3Z Motor Service Procedure
3ZG Series
Parker Hannifin Corporation
Hydraulic Pump & Motor Division
Greeneville, TN 37745 US
5
Note: Before troubleshooting any system problem, check service literature published by the equipment and/or
component manufacturers. Follow their instructions, if given, for checking any component other than the 3Z unit.
Preparation
Make your troubleshooting easier by preparing as
follows:
• work in a clean, well-lighted place;
• have proper tools and materials nearby;
• have an adequate supply of clean
petroleum-based solvent.
WARNING: SINCE SOLVENTS ARE FLAMMABLE, BE
EXTREMELY CAREFUL WHEN USING ANY SOLVENT,
EVEN A SMALL EXPLOSION OR FIRE COULD CAUSE
INJURY OR DEATH.
WARNING: WEAR EYE PROTECTION AND BE SURE
TO COMPLY WITH OSHA AND OTHER MAXIMUM AIR
PRESSURE REQUIREMENTS.
Preliminary Checks
Hydraulic systems are often trouble-free. Hence, the
problem an operator complains of could be caused by
something other than the hydraulic components.
Thus, once you have determined that a problem
exists, start with the easy-to-check items, such as:
• parts damaged from impact that were not properly
repaired, or that should have been replaced; and
• improper replacement parts used in previous
servicing
• mechanical linkage problems such as binding,
broken, or loose parts or slipping belts
Troubleshooting Guide
Hydraulic Components
If you think the problem is caused by a hydraulic
component, start by checking the easy-to-reach items.
Check all hoses and lines for cracks, hardening, or other
signs of wear. Reroute any usable hoses that are kinked,
severely bent, or that rest against hot engine parts. Look
for leaks, especially at couplings and fittings. Replace
any hoses or lines that don’t meet system flow and
pressure ratings.
Next, go to the reservoir and filter or filters. Check fluid
level and look for air bubbles. Check the filter(s). A filter
with a maximum 40 micron filtration is recommended for
the 3Z system.
Visually check other components to see if they are
loosely mounted, show signs of leaks, or other damage
or wear.
Excessive heat in a hydraulic system can create
problems that can easily be overlooked. Every
system has its limitation for the maximum amount of
temperature.
After the temperature is attained and passed, the
following can occur:
• oil seal leaks
• loss of efficiency such as speed and torque
• pump loss of efficiency
• pump failure
• hoses become hard and brittle
• hose failure
A normal temperature range means an efficient
hydraulic system. Consult the manuals published
by equipment and/or component manufacturers for
maximum allowable temperature and hydraulic tests
that may be necessary to run on the performance of the
hydraulic components. The 3Z is not recommended for
hydraulic systems with maximum temperatures above
200°F (93.3°C).
