2000kg brake coupling on 1000kg camper

[Shazmacca]

I cannot find an answer to this question. I helped my son in law build an off road camper trailer. He is a truck body builder and has done a wonderful job on the camper.

The coupling is a standard 2000kg unit for cable brakes. The trailer is about 750 kg empty so ATM about 1000kgs. Under braking the coupling does not appear to be sliding and applying the brakes.

He put grease on the slide and there are no marks from it sliding in and out under braking. I figure the spring tension should be the same no matter the rating of the coupling. The forward pressure applied to the tow bar under brakes should not need to be more for a heavier trailer. Otherwise the cars brakes would need to work harder. I mean the same amount of pressure should apply the brakes if the trailer is 1000kg or 2000kg.

Anybody know the answer?

[stevo]

Had a similar problem with a previous camper with hydraulic over-ride brakes. The slider only moved a few millimetres when hard braking meaning it was not effective at all. Dis-assembled it and got a 1 tonne spring from Carac in Melb (about $25) and this improved the travel and brake graduation. The springs are different colours for the different ratings. I put them side by side on the bench and could push slightly down with the palm of my hand on the 1 tonne spring but could hardly move the 2 tonne one. Easy to get the spring out- it just drops out the bottom when the nut is undone and the slider pulled forward. The hardest part is removing the roll pin in the nut if it does not go fully through.