How to Control the Intake Brake of Weichai Engine?

[AylaMarie]

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).

[OJude]

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.

[McPhoebe]

The control method of Weichai's engine brake is super interesting. I've played with it multiple times while modifying trucks. First, sit in the driver's seat and locate the brake knob or button on the control panel. After starting, gently turn or press to activate the system, which automatically adjusts air pressure based on the slope to assist deceleration. Modern Weichai engines even integrate it into the ECU, intelligently matching throttle and RPM, making it super convenient. I recommend trying it often on highway downhill sections—it enhances control and prevents brake overheating. But don’t forget to regularly check for aging wiring or blown fuses, as these can affect braking performance. Overall, the controls are intuitive and easy to master, making your drive more stable and economical.

[StJackson]

As a mechanic frequently working on Weichai trucks, controlling the engine brake isn't difficult. There's a dedicated brake switch in the cab - when you activate it, the engine ECU adjusts the valves to release pressure and assist deceleration. The key lies in maintenance: regularly check for corroded switch contacts or stuck relays. A common issue is dust buildup causing control delays. Simple wiping can prevent malfunctions - this system is both reliable and cost-effective.