How to Control the Intake Brake of Weichai Engine?
2 Answers
Here are the control methods for the intake brake of Weichai engine: 1. First gear control: Press the brake switch X1-65, the voltage at the control terminal X1-38 of the intake brake relay changes from 24V to 0V, the first gear intake brake relay engages, and the first gear intake brake solenoid valve starts working. 2. Second gear control: Press the brake switch X1-56, the voltage at the control terminal X1-72 of the intake brake relay changes from 24V to 0V, the second gear intake brake relay engages, and the second gear intake brake solenoid valve starts working. Here are the extended prerequisites for using the intake brake: 1. Condition one: The engine speed is above 1000 rpm. The engine water temperature is above 75°C. The transmission is in gear (neutral signal is 0, not in neutral state). 2. Condition two: The clutch pedal is released (throttle opening is 0). The throttle pedal is released (throttle opening is 0).
Weichai's engine brake is actually part of the exhaust brake system, which we veteran drivers often use when driving long-haul trucks. Controlling it is quite simple—mainly operated via a brake switch or button in the cabin. To activate it, you just turn the knob or press the button, and the engine control unit automatically monitors the RPM and load to adjust the pressure release in the cylinders. Engaging the engine brake during downhill driving helps decelerate the vehicle, reducing brake pad wear while being fuel-efficient and safe. I should remind you not to use it on slippery roads to avoid skidding, and during maintenance, check if the switch has good contact—occasionally, relay issues can make the brake less responsive. Overall, this control method is practical and efficient, making your Weichai engine more durable and saving a lot on repair costs.