“Poor performance may also indicate excessive wear to one or more internal components in either the charge pump or high--pressure system components,” says Kanitz. “This may signal impending catastrophic failure and it should be investigated and corrected immediately to minimize costly repairs.”

Startup After Repair

Any time a hydraulic system is repaired, contaminants are introduced. Monitoring oil cleanliness after a repair is paramount to prevent problems down the road. “There are standards that every hydrostatic manufacturer has related to the cleanliness level needed at startup,” says Sporrer. “We recommend an ISO grade 23/21/15 right after startup. That is cleaned up to a 22/18/13 over a short period of time.”

Oil lines and pumps are often drained of oil during repair. If these components are not primed with oil prior to startup, they could be damaged.

“Every hydrostatic manufacturer has a startup procedure that involves making sure the cases of the hydraulic units are pre--filled with oil, and there is a clean shot of oil coming through the inlet lines into the units themselves,” says Sporrer.

“Then, as you start up the machine, you may crank it for 30 seconds before actually starting the engine. That primes everything.” The engine is then run at low idle for a short period of time.

This type of procedure helps ensure components have an adequate oil supply and will not be damaged from oil starvation during initial startup.