DAF Air Suspension Issues Explained

In this brief article we are going to discuss the different DAF Air Suspension problems, what the causes are, and Troubleshooting Tips.

What are the most common DAF Air suspension issues? 

The most common DAF Air suspension issues are:

  • Suspension not raising
  • Air Bag Leakage

DAF Air Suspension

The DAAF Air suspension is based on the WABCO ECAS (Electronically Controlled Air Suspension) system. The traditional truck air suspension system uses a mechanical Level-sensing valve, where a mechanical lever opens and closes the valve based on its calibrated height setting.

The ECAS, on the other hand, operates similar to most car air suspension systems, where the height is sensed by an electronic height sensor, The height sensor is connected via a mechanical lever to the suspension. When the suspension moves, the lever mechanism movement causes a voltage change. This voltage is transmitted as a signal to the Electronic control Unit (ECU) of the Air system, which then signals the Valve block to Open/Close as per the instruction given.

Air Bag Leakage

  • Air bag leakage, in more cases, is a sudden Blow-out event because of the very nature of the duty cycle that the trucks are put through
  • The advantage with the 8-Bag system is that, even if one air bag blows out, it would be possible to level the chassis to some extent by lowering it and supporting at the remaining 3 corners.

Suspension not raising

  • Using the wired remote control next to the seat, suspension was first lowered. On pressing the Raise button, the suspension failed to raise
  • Check the electrical connectivity of the remote control
  • Next, check the height level sensors at the rear axle, if they are broken or detached, then the solenoid valves to the rear axle would not open and close correctly
  • If the connectivity is all clear, there could be an issue with the remote itself

Rough Ride Issue

  • Several of the DAF 8 bag suspensions reported a rough ride issue especially when they had the Airglide 100 suspension
  • The issue seems to be related to the way that the Air suspension Ride height is set up
  • The Air Bags have internal bump stops that are relatively huge
  • The level control valve needs to be calibrated in such a way that the Normal Ride Height of the truck is high enough with sufficient travel to avoid contacting the bump stops
  • The issue is best sorted out by an experienced DAF mechanical expert

Suspension not Lifting

  • This issue is mostly seen on the DAF XF Model
  • After lowering, Hitching and loading the rear suspension fails to lift
  • The issue is related to the rear suspension level control sensor. If the sensor is either broken or not properly calibrated, the air supply valves to the rear air bags do not get opened.
  • One more possibility is if there is a leak in one of the air bags. In case of an air bag leakage, the compressor is unable to compensate for the loss of pressure

Conclusion

In this brief article we have discussed the different  DAF Air Suspension problems, what the causes are, and Troubleshooting Tips.

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