Thread: Electric Brakes not locking up

Re trailer brakes, if working correctly 10" electric brakes adjusted to full on an empty trailer will lock up the wheels the moment you touch the pedal in the slightest way.
They should in fact still be able to lock it up if adjusted anywhere over 50% depending on the weight of the trailer.

My caravan has 10" brakes and fully loaded at about 2.5 ton I can pull up the Disco from 60 kph just using the trailer brakes quite easilly.

Good luck sorting it out.

cheers,
Terry

The magnet arm has flats at the pivot that spreads the shoes apart. If 1 moves when going forwards and the other when going backwards then the spreading is working. Perhaps the shoes aren't adjusted properly and only the ends of the shoes are contacting the drum. Otherwise if there's a leading and trailing shoe they could be fitted backwards, ie to the wrong side of the trailer. If so, swap shoe positions on the backing plate and put the outer face inwards.

Have you got enough adjustment wound on?

Wind it up until you hear it dragging and then back off a couple of notches. It should have no problems locking up being that light. What size wheels have you got on it.

Originally Posted by walc100

Have you got enough adjustment wound on?

Wind it up until you hear it dragging and then back off a couple of notches. It should have no problems locking up being that light. What size wheels have you got on it.

I have it wound up untill I feel it dragging when I spin the wheel. Tighter than I would normally do on the Landy brakes.
I have 7.50 x 16,s on it. I wonder if its the bigger wheels.
I emailed Dexter Brakes in the US. These are supposed to be a locally made clone. They said that both shoes are supposed to work even though it only looks like one shoe is being used at a time.
I dont get any braking untill the rotary control is at least half way.
I will just have to use it and maybe the shoes will bed in

Originally Posted by Graeme

The magnet arm has flats at the pivot that spreads the shoes apart. If 1 moves when going forwards and the other when going backwards then the spreading is working. Perhaps the shoes aren't adjusted properly and only the ends of the shoes are contacting the drum. Otherwise if there's a leading and trailing shoe they could be fitted backwards, ie to the wrong side of the trailer. If so, swap shoe positions on the backing plate and put the outer face inwards.

The magnet arm has this square block above the pivot point so when the magnet is moved to the left the block moves to the right, only bearing on one shoe. The handbrake has a double ended cam so bears on both shoes.
The axle was supplied with brakes attatched so I would hope the were in the correct place. I will pull the hubs and have another look.

Originally Posted by 123rover50

I have it wound up untill I feel it dragging when I spin the wheel. Tighter than I would normally do on the Landy brakes.
I have 7.50 x 16,s on it. I wonder if its the bigger wheels.
I emailed Dexter Brakes in the US. These are supposed to be a locally made clone. They said that both shoes are supposed to work even though it only looks like one shoe is being used at a time.
I dont get any braking untill the rotary control is at least half way.
I will just have to use it and maybe the shoes will bed in

With those big wheels you might have too have them fairly tight for the bed in process until the shoes are formed to fit, after that you might find they need less travel to be effective.

How the surface for that the magnet runs?

Does the magnet arm actually have a 3-cornered block with the 4th round so as to make both shoes move in 1 direction but only 1 in the other, and that axle has been fitted with the 2 shoe movement operating in reverse rather than forwards?

Okay, pulled left hand hub so you can see the setup. Front is to the LHS.
First pic is of brake at rest.


Second pic is with magnet arm moved back[ to right] so square block moves shoe to left or front as trailer is going right to left. Only the left shoe moves.


Third pic is with magnet arm to left as if trailer is in reverse. Square block now moves only the other shoe. Left shoe does not move.


If the pivot was where the square block is , it would rotate and the opposite corners would push both shoes at the same time no matter if in forward or reverse.
As it is I cant see how both shoes can work together.
But then it has been said that I am not the sharpest knife in the drawer.
Didiman