🔍 Key Concepts

• Role of the speed signal (control air 30–70 psig) line and how it changes with engine rpm • Function of the C2 speed-slip relay valve versus the three different H5 relay valves (governor limit, inflation, and boost) • Where the diagram shows setpoints for clutch inflation air during slip (e.g., 15–25 psig) compared with full lockup pressures (70–75 psig)

💭 Think About

• On the diagram, trace the path from the engine speed control governor (speed signal) to the clutch inflation air line specifically during low rpm, partial-slip conditions – which valve sits between them and modulates pressure? • Compare which valve is labeled with setpoints related to min speed/max slip and full pressure/lockup; which valves, by contrast, are only associated with higher setpoint pressures like 70–75 psig? • Ask yourself: during maneuvering at low rpm, do you want a valve that simply boosts pressure, one that limits the governor signal, or one that proportionally processes inflation pressure as a function of speed signal?

✅ Before You Answer

• Identify the valve whose outlet goes directly to the clutch inflation air line during slip, and is controlled by the speed signal line. • Verify which valve symbol carries the note: “Setpoint – Min Speed/Max Slip: 15 psig / Full Pressure/Lockup: 25 psig clutch inflation air” – that is the one handling slip pressures. • Confirm that the other valves with labels like 70–75 psig clutch inflation air are associated with higher-pressure lockup/boost functions, not normal low-rpm slip maneuvering.