After studying this chapter, you will be able to:
Explain how metering valves operate.
Explain the purpose and construction of the proportioning valve.
Discuss the reason load-sensing proportioning valves are used.
Explain the purpose and construction of the residual pressure valve.
Discuss the operation of a pressure differential valve and switch.
Explain the purpose and construction of the low brake fluid switch.
Explain the purpose and construction of the brake light switch.
Identify the reasons for using steel hydraulic lines.
Identify types of brake line flares.
Discuss why flexible hoses are used to connect some brake parts.
Identify various types of brake fittings and explain their function.
Chapter
9
Hydraulic Valves,
Switches, Lines,
and Hoses
151
Important Terms
Pressure control valves Residual pressure valve Armored line
Brake switches Pressure differential valve Double-lap flares
Metering valve Combination valve Interference angle
Proportioning valve Low brake fluid switch ISO flare
Load-sensing proportioning Brake light switch Flare-nut
valve
Stoplight switch Banjo fitting
Height-sensing proportioning
valve