A vacuum pump on a diesel engine is a device essential for generating vacuum, primarily used for the braking system. Unlike gasoline engines, which naturally produce intake manifold vacuum that can be used for brake assistance, diesel engines do not create significant manifold vacuum due to how they control airflow (via the throttle body is generally wide open, controlling speed via fuel injection). Therefore, a dedicated pump is required.
Function of a Diesel Vacuum Pump
The main function of a vacuum pump on a diesel is to evacuate the air from the brake booster tank, thus creating vacuum. This vacuum is then used for brake application, specifically to assist the driver in applying the brakes by multiplying the force exerted on the brake pedal.
Without a vacuum pump, applying the brakes would require significantly more physical effort from the driver.
How it is Driven
According to the reference, the vacuum pump is a device which gets the drive from engine cam shaft. This means it is mechanically linked to the engine's internal rotation.
It is also noted that in some designs, it is driven by the alternator shaft. This indicates there are variations in how the pump receives its power, either directly from the engine's camshaft rotation or indirectly via the alternator's rotation.
Key Aspects
Here's a quick breakdown:
- Purpose: Creates vacuum for the brake booster.
- Location: Mounted on the engine or near the alternator.
- Drive Source: Primarily driven by the camshaft; sometimes by the alternator shaft.
- Benefit: Assists braking, making it easier and more effective.
Summary Table:
| Feature | Description |
|---|---|
| Main Function | Evacuates air from the brake booster tank, creating vacuum for braking. |
| Drive Source | Gets drive from engine cam shaft or alternator shaft (in some designs). |
| Benefit | Aids in brake application by providing power assist. |
In essence, the vacuum pump is a critical component in a diesel vehicle's braking system, ensuring safe and efficient deceleration by providing the necessary vacuum assistance.
