Failures and Solutions, for Sinotruk Howo Truck Cabin Lifting Pump and Cylinder

Importance of Truck Cabin Lifting Pump and Cylinder

Failure of the Sinotruk Howo truck cabin lifting pump and cylinder can significantly impede the operation and functionality of the vehicle. Firstly, malfunctioning of the lifting pump may lead to an inability to raise or lower the cabin properly, impacting driver visibility and safety. Additionally, failure of the lifting cylinder can result in instability or imbalance of the cabin, posing a risk of accidents or damage to the vehicle structure.
To address these issues, prompt diagnosis and repair of the cabin lifting pump and cylinder are crucial. Replacement of faulty components or repair of damaged parts ensures the proper functioning of the lifting mechanism, restoring the capability to adjust the cabin position as needed. Regular maintenance and inspection of these components can help prevent potential failures, enhancing the reliability and safety of the Sinotruk Howo truck during operation.

The oil cylinder is working fine (especially the electric pump), but the cab is not moving.
Causes of failure and solutions:

The switch is not at the lifting position → Move the switch e to the lifting position.
The air plug on the oil tank is blocked → Clean the air plug.

The lift controller is not responding, and the electric pump does not work.
Causes of failure and solutions:

Power is not connected → Check if the power is connected and whether the vehicle is at neutral gear.
The air plug on the oil tank is blocked → Clean the air plug. (howo truck parts)
The pins of the connector are loose thus the contact is poor → Re-fix the pins of the connector.
The fuse burned to → Check the fuse box.
Incorrect installation for controller → Check wires and tubes. Please see the images below.

The relay of controller is making tick-tick sound, and the electric pump motor does not work.
Causes of failure and solutions:

The electric circuit is not connected well → Check whether the vehicle is in neutral gear, and check whether the wires are burned or cut or disconnected, check fuses also.
The motor is damaged → Replace the electric pump assembly.

After the cab is raised halfway, the electric pump stops working.

Causes of failure and solutions:
The electric pump control circuit is cut → Check whether the power of the whole vehicle is connected and whether the whole vehicle is in neutral gear, and check fuses.

The pump works, but cabin no longer lifting after lifting at halfway.

Causes of failure and solutions:
No enough oil in the oil tank → Lower the cab to the original position, and add oil. Please see image below.

The cab continuously slides down.

Causes of failure and solutions:
The inside of the hydraulic system is contaminated, causing the steel ball inside the hydraulic control valve does not seal the hole well → Clean the oil circuit route and add new oil.

The system works, but cabin lifts or falls more slowly than normal.
Causes of failure and solutions:

The air plug on the oil tank are blocked → Clean the air plug.
The inside of the hydraulic system is contaminated → Clean the whole oil route and add new oil. (WG9719826001)

Cabin simply does not fall.

Causes of failure and solutions:
Parking at the position for too long, the cylinder limit pawl is locked /jammed → Move switch to “up” position, pump it up a little, then switch to the “down” position, and fall.

When the cab is falling, bubbles and oil overflow at air plug, and oil leakage at oil pump and oil sump, or even the oil sump bursts.