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Thinking before tinkering

Posted: 18 Mar 2010
by Bx Bandit
How to have a reversing trailer without auto reverse brake shoes?

This is the situation: My current old style hitch has a tab to flip down so that if I need to reverse, I need to get out the car, flip the jobby over and the brakes are in effect annulled.

However, I'm changing axle to a land Rover defender axle and mounting a hitch that Vanny gave me. The hitch is an auto reverse compatible hitch so there is no means to physically lock the hitch to prevent the brakes locking up when reversing.

So, my thoughts are:

1) Make up a simple mechanism such that, with a locking bar inserted, I can lock the sliding hitch jobby to prevent the brakes coming on in reverse.
2) As above but have an electric solenoid to poke said bar and auto lock the mechanism when reverse is selected
3) A different approach: use the axle hydraulic brake system instead of cables thus requiring a master cylinder of sorts that is pushed by the sliding hitch. The auto reverse aspect would be enabled by an elctro/hydraulic valve. Operation controlled by selecting reverse etc.
This however would need to be doubled up with cables for hand brake use.

I prefer option 3 but welcome any advice/opinions/input etc. I even considered,just for a brief moment, of fitting the rear Xantia subframe but decided I couldn't be arsed!

Re: Thinking before tinkering

Posted: 18 Mar 2010
by docchevron132
Option 3 sounds good, but I often find that simple is best.
In which case 1 or 2 would be my fave..

Re: Thinking before tinkering

Posted: 18 Mar 2010
by Philhod
:) Yeah ! Just drill a hole in it and weld a pin to a bit of chain, with a recepticle for pin when not in use.
Simples.

Re: Thinking before tinkering

Posted: 18 Mar 2010
by Vanny
Philhod wrote:Just drill a hole in it and weld a pin to a bit of chain
This is what the break down services (AA and RAC) used to do until one of them destroyed the car it was towing having left the pin in!

Given the age of the hitch AND with it being from a caravan i suspect there might be a hole there already, possibly covered by a cap.

Re: Thinking before tinkering

Posted: 18 Mar 2010
by mat_the_cat
Some food for thought with the complex option - you cn get hydraulic handbrakes for rally cars and the like. Don't reckon they'd be cheap, and IMO it's probably a bit too much of a faff. Neat though.
Also bear in mind that Defenders had the handbrake mechanism on the output shaft from the gearbox, so as it stands the axle will have no cable operated brakes.

Re: Thinking before tinkering

Posted: 19 Mar 2010
by Bx Bandit
:shock: What!? :shock: :shock: :shock: :shock: :o No hand brake scooby? These are drums mind - would that make a difference? I need to check the axle now!

I agree a pin/mechanical set-up is best for simplicity, but it's major PITA to have to get out the car every time you need to reverse.

I don't think the facility is already there Vanny as your hitch has the 'energy store' springs specifically for use on auto reverse brakes.

Does anyone know what sort of pressures the hydraulics are exposed to under braking?

Re: Thinking before tinkering

Posted: 19 Mar 2010
by mat_the_cat
'Fraid so, there is one big drum on the back of the transfer box so that the action of the brake is magnified by the ratio in the axle diffs. And with the centre diff lock on it acts on all wheels so I can see why they did it that way. Just don't try handbrake turns in a Landy!
With yours being drums it might be quite easy to make a mechanical actuator to move the shoes instead of the brake cylinder, but I suppose the hydraulic option is becoming more appealing!

Re: Thinking before tinkering

Posted: 19 Mar 2010
by Philhod
I would have thought it would be easier with drums? Just fit a couple of wheel cylinders in addition to the mechanical set up and connect them to a pump lever near your seat.
There are "stop leak" connectors you can get that just push in, similar to an air line.
Thinking about it you could operate that set up with air anyway.

Re: Thinking before tinkering

Posted: 20 Mar 2010
by Bx Bandit
Where would I get lever cylinders if they never made them? effin crab sticks!

Re: Thinking before tinkering

Posted: 20 Mar 2010
by docchevron132
Surely the easier way would be to get something like Cavalier / Calibra back plates, fitted with the cylinders, but dont use the hydraulic aspect, but instead use the handbrake levers that act on the bottom of the brake shoes?

Re: Thinking before tinkering

Posted: 20 Mar 2010
by Bx Bandit
Probably mate, but you need to match back plate holes up or else re-weld the new fuckers on and then I'm in for a whole load of brake related arse raping. Besides, who on earth would want Cavalier or any Griffin related stuff on even a lowly trailer?!.................................................
















































:mrgreen: [coat]

Re: Thinking before tinkering

Posted: 20 Mar 2010
by docchevron132
well, yeah, I mean, any old backplate that would fit would do, only used the Calibra as an example since I did the rear brakes on one t'other week, and it seemed to fit the bill like..

Re: Thinking before tinkering

Posted: 20 Mar 2010
by Philhod
:lol: Or the ones off the Picasso?
You could use one of those pumps off any car that has hydraulic seat raising.

Re: Thinking before tinkering

Posted: 21 Mar 2010
by Bx Bandit
:o "hydraulic seat raising"

No one will be sat in the trailer and tbh a seat riser wouldn't make an awful lot of difference to the comfort factor!

Re: Thinking before tinkering

Posted: 21 Mar 2010
by Philhod
:lol: :lol: Oh. Very obtuse!! I meant as a brake control! twonk!!!

Re: Thinking before tinkering

Posted: 21 Mar 2010
by mat_the_cat
Bx Bandit wrote:No one will be sat in the trailer
If they did you could just get them to operate the brakes... [chin]

Re: Thinking before tinkering

Posted: 21 Mar 2010
by Way2go
/\ Classic! [bow]

Re: Thinking before tinkering

Posted: 21 Mar 2010
by Philhod
If they did you could just get them to operate the brakes...


:lol: :lol: :lol: :lol: :lol: :lol: Obviously you will now have to construct a seat for Mrs Bandit. :P

Re: Thinking before tinkering

Posted: 21 Mar 2010
by Bx Bandit
:lol: :lol: Has anyone seen Burn After Reading? It's a Coen Brothers film with Brad Pitt and George Clooney. There's a very............... [chin] erm............... [chin] interesting seat in the film. One that Mrs Bandit may like!

Re: Thinking before tinkering

Posted: 21 Mar 2010
by docchevron132
she could just use my cock instead?
Organic is often better...