Form No. R92.00 Rev. 10/03
3
START UP PROCEDURE (continued...)
15. When the system is running normally, check fluid
level and temperature at the reservoir. Repeat these
checks periodically. Excessive fluid temperatures will
damage the pump. If fluid temperature does not
stabilize at 140° F (60° C.) or less, stop the system
and take appropriate corrective action.
16. System is operational. Follow appropriate
maintenance procedures to assure fluid cleanliness
and proper operating temperature.
REPLACEMENT PUMP INSTALLATION
To prevent premature pump failure, make
sure that the entire hydraulic circuit is
flushed completely clean before
installing and operating a replacement
pump.
Simply draining the reservoir or relying on the
system’s filters is not enough to adequately clean the
fluid. Debris trapped in other components or lines
may damage the components themselves, or be
drawn into the pump. Failure to properly flush the
system before installing a replacement pump voids
the pump’s warranty.
The following procedures checklist will help you
replace a hydraulic pump with confidence that it will
provide satisfactory pump life.
1. Determine the cause of the failure (be sure you
have found the cause, and not simply a symptom).
2. Eliminate the cause of the failure.
3. Drain the entire circuit, including cylinders, motors,
reservoirs, control valves, heat exchangers, and
filters.
4. Remove system lines and components. Flush with
a compatible solvent, or clean filtered oil to remove
contamination that may have entered the system
when the pump failed. Be certain that fluid has been
flushed from cylinders.
5. Visually inspect components for possible
contamination, and for proper operation. Pay special
attention to wipers on cylinder rods. Be sure that the
rods are free of nicks and scratches.
6. Flush the reservoir using pressurized solvent. Use
clean, dry, lint-free cloths to ensure a clean interior.
Inspect the filler/breather (if used) and the suction
strainer for cleanliness.
7. Install a new filter with a 10 micron or better
element, and low Beta ratio. If the machine does not
have a filter, install one that meets these
specifications.
8. Fill the reservoir with new, FILTERED oil of the
recommended type. Be certain to monitor the fluid
level, since the entire system (not just the reservoir)
must be filled.
9. Re-install all system lines. Visually inspect to make
sure they are clean, and free of contamination. Be
sure that all inlet fittings are tight and clean.
10. Install the new pump.
11. Follow the start-up procedures given on pages 2
and 3 of this manual.
12. Cycle all cylinders and operate all motors at
normal operating speeds for 20 minutes. While
operating, observe the reservoir fluid level, since all
components will be filling with hydraulic fluid.
13. Replace the filter element, and check the fluid
level. Add new, clean, filtered oil if required.
To assure that your replacement pump performs at
the same level as the original pump, check daily for
proper fluid level, filter condition and leaks. Change
fluid at recommended intervals. Good fluid
maintenance is especially important when using other
than mineral based fluids.
Component problems and circuit problems are often
interrelated. A poorly designed circuit may operate
with apparent success, but cause a component of the
system to fail. The component failure is the effect,
not the cause of the problem. The following general
guide is offered to help you locate and eliminate the
cause of problems by studying their effects.
Problem
Possible Cause
Look For
Noisy Pump
Air in fluid
Leak in suction line
Leak in shaft seal
Low fluid level
Turbulent fluid
Return lines above fluid level
Gas leak from accumulator
Excessive pressure drop in the inlet line
from a pressurized reservoir
Cavitation in pump rotating group
Fluid too cold, too viscous or too heavy
Shaft speed too high
Suction line too small, or collapsed
Suction line strainer dirty or too small
Continued on Page 4
TROUBLESHOOTING GUIDE
