I have just replaced all of the suspwension units on my trailer with 1300 kg indespension units previous units were fubbared an only one axle had breaks these were hydraulic? The new units use cables instead ? Due to this I have made a lever arrangement to pull the brake on whe the towing hitch pushes in, my concer is that when the hitch is connected to the brake sytstem it wont push in so doesnt appear to apply the brakes if I pus on the hitch. The only thing I can think of is that there is a mechanism for reversing without appyling the brakes if so could the be the reason??

I'm a bit confused by what you've written but if you've used proper auto-reverse trailer brakes, as fitted to most modern trailer/caravan hubs, the brakes won't engage when you reverse the trailer as the mechanism in the drums sort of collapses when the drum turns backwards.

Its difficult to explain really if the hitch is not connected to the brake system it can be pushed inlike a shock absorber when I connect it to the 8mm rod that pulls the brake the hitch does not push in. Is this because I am effecrively reversing the trailer by pushing it and forward inertia isnt being applied?

What is the hitch like is it like the type with a big spring in ? or is it like whats on a alco caravan chassis ?
do you have a photo Mate
Graham

What sort of hitch is it? We need piccies perhaps!

Its a Bradley one which previously operated a master cylinder by way of a pushrod I am now using the rod to connect to lever producing a pulling motion I do think ther will be a big spring in there thr are also 2 grease nipples on it. Will tray ang get pictures

http://www.lsengineers.co.uk/bradley-d40-50mm-ball-hitch-coupling.html

Is it like this ?
If so it has a plate that swings over to stop the brakes coming on when reversing
There is a big spring inside it to damp the pushing effect by the weight of the trailer / load
Graham

Probably just that the force needed to push the brake mechanism is more than you can apply by hand - from my recollection with a caravan, the lever was pushed by the hitch only two or three inches from its pivot, whereas applying the handbrake used a lever nearly two feet long operating on the same pivot and push point.

Yes like that jacko even without the plat swung over the hitch wont depress so I think its possible something in the brake drums that stops the braking when reversing

this is what I am working with


Description


Description


all help appreciated,

Without the hitch attached, how much/far does the brake rod pull? If thats adjusted so it has littlle play, then the hitch can't move any distance. Maybe you need more leverage at your relay lever (looks 1:1 at the moment) to allow it to work better but pushing by hand is rarely enough force to operate the brakes.

The reversing mechanism means that as the shoes contact the drums the rotational force on the shoes forces them down ramps at the end brackets and releases the brake shoe from the drum. Going forward doesn't have that effect. It doesn't block/stop the movement of the cable so you should still feel the movement.

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Originally posted by adithorp
Without the hitch attached, how much/far does the brake rod pull? If thats adjusted so it has littlle play, then the hitch can't move any distance. Maybe you need more leverage at your relay lever (looks 1:1 at the moment) to allow it to work better but pushing by hand is rarely enough force to operate the brakes.

The reversing mechanism means that as the shoes contact the drums the rotational force on the shoes forces them down ramps at the end brackets and releases the brake shoe from the drum. Going forward doesn't have that effect. It doesn't block/stop the movement of the cable so you should still feel the movement.

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Not the foggiest! Sorry thats not very helpful... even if true.

I could have a measure of the lever lengths on mine tomorrow which should give a clue as to whats normal. It might be 1:1 for all I know.

If you had a handbrake you'd know how far the rod pulls and then work out a leverage to give that movement from say 1/2 or 2/3 the hitch max movement... maybe?