Originally Posted by ribber
I must admit I thought it was the damper movement that pushed the linkage to pull the brake cable that applies the brakes.
If the damper is not moving ie jammed/seized then the brakes won't apply and you'll get that thump when braking. Again I thought also the damper takes up the movement when pulling away, to soften the jolt.
All of the above. My point is, if the brakes don't work, then you will still get a thud, regardless of the state of the damper. If the brakes don't work, the trailer compresses the damper, the damper bottoms out & the trailer runs into the tow all causing the thud. On a properly set up trailer, the brakes should retard the trailer before the damper bottoms. The brakes & damper work in tandem, one is no good without the other.