Section 1 - General Information
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Terms and Definitions
Colour Coding
Hydraulic Schematic Colour Codes
T11-006
The following colour coding, used on illustrations to denote
various conditions of oil pressure and flow, is standardised
throughout JCB Service Publications.
Red
Full Pressure: Pressure generated from operation of a service. Depending on application this
may be anything between neutral circuit pressure and MRV operating pressure.
Pink Pressure: Pressure that is above neutral circuit pressure but lower than that denoted by Red.
Orange Servo: Oil pressure used in controlling a device (servo).
Blue Neutral: Neutral circuit pressure.
Green Exhaust
Light Green Cavitation: Oil subjected to a partial vacuum due to a drop in pressure (cavitation).
Yellow Lock Up: Oil trapped within a chamber or line, preventing movement of components (lock up).