The vacuum pump is the heart of sewage vacuum tanker trailer, it suck out the air left inside the tank for the generation of vacuum. Due to the air pressure difference, sewage as well as other sludge can be absorbed inside the tanker. It’s a common physical phenomenon.
When the rotor of the vacuum pump starts spinning, the centrifugal force makes the spinning plate stick to the interior pump body, expanding the absorption chamber until pump rotors stop and the air isolated. The air will be exhausted when the interior pressure reaches limited value. The pump keeps working in this way until the tanker reaches vacuum state.
If the vacuum pump fails to spin, which is a common malfunction to sewage vacuum tanker trailer, the suction and exhaustion will fail to work as well. In this situation, check gear coupling of the PTO, or check the coupling shaft, if doesn’t spin, it means the rotor shaft cracks. Some other reason might also cause the malfunction:
- Leakage of the rear door or air drainage pipe. It might be due to the broken sealing of rear door or crack of the ball valve or flange.
- Some air remain inside the pipe, check impurity inside the valve and pipe, sealing should also be inspected.
- When the vacuum pump reaches maximum temperature, the air suction pipe might be stuck, or there is water remaining inside the air-water separator.
- Only sewage drainage can be conduct instead of sewage suction, check if the tanker is full.