Dark Gray - Cutaway section
Light Gray - Surface color
Red - High pressure oil
Red/White Stripes - 1st pressure reduction
Red Crosshatch - 2nd reduction in pressure
Pink - 3rd reduction in pressure
Red/Pink Stripes - Secondary source oil pressure
Orange - Pilot, charge, or Torque Converter oil
Orange / White Stripes -
Reduced pilot, charge, or TC oil pressure
Green - Tank, sump, or return oil
Blue - Trapped oil
Brown - Lubricating oil
Purple - Pneumatic pressure
Orange Crosshatch - 2nd reduction in
pilot, charge, or TC oil pressure.
White - Atmosphere or
Air (No pressure)
Yellow - Moving or activated components
Cat Yellow - (Restricted usage)
Identification of components
within a moving group
Black - Mechanical connection. Seal
Green / White Stripes -
Scavenge Oil or Hydraulic Void
HYDRAULIC SCHEMATIC COLOR CODE