Why is my Trailer banging when I Brake?

This guide is to help identify the reasons why your trailer may be banging into the back of your vehicle when you engage the brakes. It is also giving a step by step guide for replacing a Damper.

Reasons why your trailer may be banging

Your trailer may be banging when you brake due to the Damper in your Coupling being worn. The Damper acts like a shock absorber. If the damper is damaged your vehicle may bounce, drift whilst braking or the trailer will ‘nose dive’ into the back of your vehicle. If this is the case, your Damper will need replacing.

The reason a Damper becoming damaged could be due to poor Brake Adjustment. It could also be due to the seizing of parts, which prevents the Damper from doing its job correctly. If your Damper has been worn for some time, the Stop Ring can also begin to wear out.

All parts are shown in order on the drawing below. Use the numbers on the drawing to find the part you require.
Bradley Doublelock HU3HE 2750kg exploded Drawing

Cast body (not available as spare) Coupling head

Number 10 is showing where the to find the Damper in a Coupling. If this part is damaged, it leads to your Trailer banging when braking as stated above.