Practical Hydraulic Systems: Operation and Troubleshooting for Engineers and Technicians

After reading this chapter the student will be able to:
Understand and explain the various causes for failure in a hydraulic system
Carry out preventive maintenance of system
Understand the functions and importance of sealing devices in a hydraulic system
Carry out preliminary troubleshooting activities for determining the causes of malfunctioning in a hydraulic system.
In the early years of fluid power systems, maintenance was frequently performed on a hit or miss basis. The prevailing attitude then was to fix the problem only after the system broke down. With today's highly sophisticated machinery and with the advent of mass production, industry can no longer afford a failure, as the cost of downtime is prohibitive. In this chapter we shall try and identify some of the common causes of hydraulic system failures and also examine the various maintenance practices to be followed in a hydraulic system along with the essentials of effective troubleshooting.
The most common causes of hydraulic system failures are:
Clogged and dirty oil filters
An inadequate supply of oil in the reservoir
Leaking seals
Loose inlet lines, which cause pump cavitations and eventual pump damage
Incorrect type of oil
Excessive oil temperature
Excessive oil pressure.
A majority of these problems can be overcome through a planned preventive maintenance regime. The overall design of the system is another crucial aspect. Each component in the system must be properly sized, compatible with, and form an integral part of the...