Caravan coupling jolt

[robwales]

I am helping to sort out a caravan, one of which's problems is that the coupling hitch jolts forward when braking.

There is a cylinder containing a spring between the coupling and the rod that goes to the rear brakes. I can extend this all the way by hand.

My guess is that the spring has become too weak so it extends to the limiter at the first sight of braking, causing the jolt, rather than braking smoothly.

Can anyone offer any wisdom on this? Thanks

[davidjpowell]

There is a hydraulic cylinder which I believe goes between the coupling head and the actual mounting, sounds like this had gone.

Happened to me when I had a boat trailer. It felt like I was being rammed by a 1,000 HGV's when braking.