TEMPERATURE SHOCK

What is temperature shock?
When there is a significant difference between the temperature of a hydraulic component and the fluid being supplied to it, rapid, localized heating of the internal parts of the component can occur. This causes individual parts of the component to expand at different rates, resulting in interference between parts that normally have fine clearances.
How does this happen?
Temperature shock occurs when part of a hydraulic circuit is operated for long enough for the hydraulic fluid in the system to reach operating temperature, and then a previously idle part of the circuit is functioned. This results in hot fluid being delivered to cold components.
How can this be prevented?
To prevent temperature shock of hydraulic motors, the motor's case must be continuously 'flushed' (positive circulation of a relatively small volume of fluid through the case). This ensures that the motor is always at the same temperature as the fluid in the system.