Call 01206 585439

You're currently on:

How to check if your coupling damper needs replacing

How to check if your coupling damper needs replacing

Coupling dampers are designed to give a smooth and efficient braking sensation when towing a trailer with a full load, therefore it’s very noticeable when the damper has failed and is due to be replaced.

A good coupling damper will last for both many miles and years providing it is checked and adjusted regularly and is kept well maintained. We do like to suggest that you should check all parts of your trailer before you set off on any long trip. Here is a ‘Quick and Simple Checklist for Maintaining Your Trailer’

If the Coupling Damper has been adjusted incorrectly, or has had poor maintenance, this can lead to premature wearing of the damper and shorten its life considerably. This is also true in the case of bad driving habits such as regular hard braking and snaking across the road.

Coupling dampers assembled within overrun couplings are pressurised, so it is difficult to check if they are working correctly because it requires a great deal of pressure to push the coupling back by hand. If you find that you can push the coupling damper back easily, this is a good sign that the damper needs to be replaced. ATE UK specialise in Coupling Damper Parts, so you will always find what you are looking for. If you cannot find the exact part, or need help, then our TechTalk Team are on hand if you call 01206 585439.


Before replacing the damper, it is worth checking that your brakes are correctly adjusted. This is done by loosening the brake mechanism at the compensator and the coupling and then, starting at the brake drum, rotating the brake adjuster.

This can be done several ways, depending on what brake set up you have:

  • Turn the brake adjuster bolt clockwise until some resistance is felt when the brake shoes begin to grip the drum. Then turn it back anticlockwise until the wheel begins to rotate freely again.
  • Advance the adjuster using a screwdriver through the hole in the rear of the brake back plate until resistance is felt as the brake shoes begin to grip the drum. Then slowly turn the brake adjuster back a few clicks until the wheel begins to rotate freely again.

Continue this process on all drums and take up the slack at the compensator and coupling.

Ensure you don’t over tighten because this will result in the brakes overheating. You can use the handbrake to check whether the compensators and brake shoes are correctly seated.

You can tell they’re correctly seated if:

  • The compensators rest at a 90 degree angle to the brake rod.
  • The travel of individual brake cables should be between 2 & 5mm.
  • The drums should be able to spin freely.

For more information on Coupling Dampers please do get in touch with our team