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How to check if your coupling damper needs replacing

A properly functioning damper for coupling can result in an easy and controlled brakes. If the damper is not functioning properly, it’s evident through the savage application of brakes or’snatching’ whenever the brakes on the towing vehicle are applied.

Prior to replacing your coupling damper, it is worth checking the adjustments on the shoes for the brakes to drums. In some cases, brakes that are not adjusted properly can cause the same problem as a damaged damper.

The dampers in overrun couplings have been pressurized therefore if they’re operating correctly , it’s difficult to determine their performance because it takes a significant quantity of force to pull the coupling back with a hand. It is possible to force the coupling back by pressing the coupling head, and simulated the overrun mechanism on light braked caravans or trailers however when you are able to pull it back with ease or it feels like it is’springy and bouncy, then the damper is failing.

Dampers are typically very reliable and can last for a long time (or several miles) In general however, the life span of a damper could be reduced due to poor maintenance or driving behavior. Continuous hard braking can reduce the life of the damper and an emergency stop can cause the damper to reach the end of its lifespan early. The most frequent reason that dampers fail to function is inability to maintain them or the incorrect adjustment. Brakes must be kept in check and adjusted on a regular basis (about once every 6 months on an average trailer) This ensures that the damper is not able to be able to withstand all the force of an overrun that occurs when braking.

If you discover you have a coupling that requires replacing, we’ve got many brands available to pick from such as:

BPW Coupling Dampers
Avonride Coupling Dampers
Knott Coupling Dampers
Indespension Coupling Dampers
Alko Coupling Dampers
Bradley Coupling Dampers

Brake Adjustment

Adjusting the brake must be done by the brake shoes. reduce the entire brake mechanism, including the compensator as well as the coupling. Always start from the brake drum, and then turn the brake adjuster
applying one of the methods below dependent on the brake setup You can:

Be sure to rotate the wheels forward direction during this process otherwise the auto-reverse mechanism could become active and make precise setting impossible.

Method 1

The bolt that adjusts the brake (usually located at the back of the backplate for the brake) clockwise until resistance is felt when brake shoes start to grasp the drum. After that, slowly rotate the bolt to adjust the brake counterclockwise until the wheel starts to spin freely.

Method 2

Move the adjuster forward using an screwdriver through the hole on the back of the backplate for the brake until the resistance feels in the threads of the brake shoes begin to grasp the drum. After that, slowly move the adjuster to backwards just a few clicks until it begins to move freely.


Continue to do this on all drums , and then pick off the excess at the coupling and compensator.

Caution! Don’t over tighten the brakes because this can result in the brakes dragging and overheat. Make sure to apply the handbrake multiple times to check that the brake compensators and shoes are properly seated. The compensators should be set in 90deg of the brake rod once the brakes have been applied. The misalignment can be corrected by adjustments to the locking nuts for cable. Verify the distance traveled by the brake cables in each case, it should be between 2 and 5mm, in case it is not, adjust the brake according to. Also, make sure that all the drums rotate freely

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