How to Replace Faulty Suspension Airbags
Most heavy vehicles are fitted with an air suspension system that is designed to cope with excessive weight and difficult driving conditions. At the core of the systems are airbags or bellows that can be automatically inflated or deflated, as conditions dictate. Yet these components are vulnerable to everyday wear and tear, and if they do deteriorate, you'll certainly notice a difference. How can you tell that something is wrong, and how can you replace these bags if needed?
What to Watch for
The first sign of a problem may be an air compressor that cycles on-off repeatedly. This device is only supposed to provide air when needed and as notified by a set of sensors. If the bag itself becomes damaged or may even leak, the system may be fooled, and you will find an overworked compressor. Soon after, you may notice that the vehicle starts to sag on one corner, indicating that the bag is deflated. The vehicle may feel generally unresponsive and the steering far from precise.
Repair or Replace
It's not always easy to repair a damaged air spring in situ, and it may need to be replaced altogether. This is a job that requires extra care due to the sheer weight involved, and you are better off using a hydraulic lift to make it a lot easier to work beneath the vehicle.
More often than not, the air spring in question will be connected to the frame of the body on top and the rear axle beneath. It may be hard to access, and you'll probably need to remove a number of panels so that you can get to the mounting mechanism and disassemble all the parts.
Before you do anything, you should disconnect the power, automatically isolating the compressor. If you don't and begin to empty the air spring, the compressor will automatically assume that the bag needs more air and begin the cycle.
In order to remove the bag, you will need to disconnect the pneumatic lines carefully to let the air drain slowly. At this stage, you must ensure that the weight of the body is adequately supported as the spring gradually deflates.
The specific process for your vehicle can typically be found in the manufacturer's manual. Reassembly is usually a simple reverse of disassembly, but you must ensure that the airbag is allowed to fill slowly while the vehicle is still suspended. You must also ensure that the bag is correctly installed with no evidence of "pinching" or other restriction before you lower the weight onto the suspension.
The Better Approach
Without adequate equipment and a lot of patience, you may find this job to be too onerous. This is why it is often better to bring in the professionals instead, as they have experience and know what to do should they encounter a snag.
For more information on truck repairs, contact a company near you.