Conversion to Electric Brakes

[mausie]

Hi all

Has anyone converted their oldie to electric brakes.

We have been thinking of doing that as part of our rebuild.

Our current set up has hydraulic over-ride.

Any advice would be great

Mausie

[millard1399]

G'day Mausie,

I'm sure other people can help you with info about their electric brakes. I still run the override cable type on my poptop.

There's no specific thread on electric brakes as such, but the subject pops up on a number of occasions on the forum. Some of the threads that might be worth reading are:

Electric Brakes Maintenance

Millard approx 1976 M46913

WDH's and Electric Brake Controllers

Hi from Newbie

1969 Viscount Duralvan A4910


And did you know you can "Bookmark" any thread after you've opened it up? Same as you bookmark any other website in your 'Favourites' or 'Bookmarks' list. I created a new folder in my Bookmarks list, and save any threads I think are interesting in that folder. Saves me having to try and remember where I saw that bit of info about the you-know-what.

cheers,
Al.

[mausie]

Hi Al

Thanks for the links they have been a big help. Looks like we go electric ;D ;D ;D ;D

We will have to ask the supplier if we have to change the hub drum or if we can keep it and only buy the backing plate.

Mausie

[Rattles]

You will have to buy the drum as the vertical face is machined to enable the electro magnets to make contact.
use link to get an idea of price.
caravansplus.com.au/catalog/index.php?cPath=34_123_472
Rattles

[kylarama]

I've done this on mine, except I went the whole hog and replaced everything. Brakes, axle, springs, coupling and the drawbar.

Your axle will already have brake flanges welded to it which are the same for hydraulic or electric.

New electric backing plates.
(pay the extra and get the ones with handbrake function)

As Rattles said new drums are required. Also override drums are generally 9" and electric are 10".
(Make sure you check what bearings your axle uses. The drums are compatible for either Ford or Holden bearings)

New coupling is needed with a handbrake lever. Although you could unbolt the hydraulic setup from the existing coupling and fit the brake lever component from a mechanical override setup. This sorts the handbrake out and just flick the reverse lever over to make the override redundant. (at $70 a new one would be easier)

Some 4mm steel cable, adjuster, clamps and a few metres of 4mm twin core electrical and away you go.


Easiest way would be to buy a conversion kit like this for $460
www.marshall-eng.com.au/Brake_Conv_Kit.html

These guys are excellent to deal with and are more than happy to give advice. They will do a cheaper price using imported components and freight, above kit uses good Alko stuff. Note: no affiliation, just a happy customer.


If your not a diyer, I'd expect a caravan/trailer repairer or mechanic would charge around 3-4 hours to fit everything and wire up the vans plug. $75-$95ph depending on where you go?

Don't forget a brake controller. Make sure you get a proportional one, not the old preset voltage type. A proportional one automatically adjusts the voltage to apply the van brakes to how hard the tow vehicle is braking. With the old preset voltage ones you'd dial in say 2 volts, but if you had to stand hard on the anchors the van brakes with just apply a gentle 2 volt braking. Or other way around.

I use a Tekonsha Primus IQ, which you can pick up off Ebay for around $90 delivered. Easy as to fit, or around 2-$300 for an auto elec at a rough guess??

[mausie]

Awesome kylarama

Just what I wanted to know.

Will I be able to retain my axle? If I read your comments right the answer is yes.

Thanks so much.

Joe is good with mechanical things - he is always doing this and that with our old Austins. ;D ;D

[mike]

kylarama, ;D ;D ;D

Mate, that's really great info for DIY install elec brakes.
About 1990, our Franklin got an AL-KO conversion which included the axle and it cost about $1500 then. So this is a really good price.

We only got it included on a new axle on impulse.
Our original axle, altho straight when under no load, would bend just with the weight of the van and the wheels would 'splay' out like the old VW rear wheels. After many cracked wheels, tyres.. got it replaced.
An alternative, suggested later, would have been to jack the van up and drop it onto an anvil placed under the axle in the centre to put a bend in it which would mean that when the weight of the van was eventually put on the axle n wheels, they would move from their 'induced' splay-in, to one of being vertical. MMMMMMmmmmmmmmmmmmmmm.

Anyhow, good stuff in your suggestion. ;D ;D ;D

mike

[millard1399]

Just an updating question in this thread. We will have to get a controller for the electric brakes on our 'new' van. Is the Tekonsha Primus IQ model on ebay for $80 the one we should be aiming for? Not looking for anything fancy, just a reputable controller that does the basics (...like stop a 17ft 4ins caravan ).

cheers,
Al.

[Deleted]

Hi Al,
do yourself a favour and buy a prodigy 2 electric brake controller,does everything except talk to you!
Cheers
hughdeani

[millard1399]

G'day hughdeani,

Ok, so I need to educate myself a bit more about these controllers. What are the benefits of the Prodigy 2 model, and why wouldn't I go another step and buy the Prodigy 3 model? I'm just looking for something that is reliable and which does the job well. I don't need something that nods and winks at me all the time, or tells me when it's time to rotate the tyres, etc. Is there somewhere where I can go to understand what the differences are between the Tekonsha models?

cheers,
Al.

[Deleted]

Hi Al,

This comparison does a reasonable job.

Tekonsha website

In terms of braking performance once set up, they are identical.

The P2 will meet all of your needs.

I've a Tekonsha that came off the ark (70's?) with fake woodgrain cover. It is proportional and still works very sweetly.

The Tekonsha units use an inertia device which measures the rate of deceleration, once the tow vehicle brakes are applied. The higher the deceleration, the higher the braking energy.

The braking energy is applied by sending 12 volt pulses to the brakes. Sometimes you can here the brakes buzz as the pulsed DC is applied. To apply greater braking energy to the brakes the 'on period' of the pulses is increased.

Maximum braking energy is 12 volts continuous.

Cheers

John k

[Deleted]

Thanks John!
Couldnt have said it better myself!
Al, I believe the prodigy 3 does everything you need and then some more.Auto elec said 3 was too complicated.
Cheers
hughdeani

[millard1399]

G'day All,

I'm currently pretending I'm an auto electrician, and am installing the electric brakes controller in the car. The installation diagram shows the power/earth cables coming from/to the battery terminals direct, but I wanted to ask other people how it was done on their car.

Do I connect the power feed cable as close as possible to the positive terminal on the battery, or is it better to wire into the Accessories part of the car, so the controller is only powered when the ignition is turned on? Or doesn't it really matter?

cheers,
Al.

[Rattles]

www.etrailer.com/Merchant2/graphics/00000001/pics/q/u/qu6890_800.jpg

See Diagram you will note the 20A auto reset cct breaker, this used instead of a fuse.

Rattles

[millard1399]

G'day rattles,

Yes, I've seen that diagram before, and it is essentially the same as the one supplied with the Tekonsha controller.

But it doesn't answer my question about whether it's better to wire direct from the battery, or to wire through the Accessories side of the car. If wired direct from the battery, does that mean there is power going to the controller at all times, and that if you didn't use the car for a month your battery goes flat, OR does power only get consumed by the controller once the brake light sends a signal to the controller? That is, no brake signal means no power drain from the battery?

cheers,
Al.

UPDATE: I hunted around the internet and found the answer: Yes, there is a small drain on the battery when the controller is connected, but it is in the order of a few milliamps - not enough to drain a battery in any hurry. Popular recommendation is to draw power directly from the battery. Alternative sources of power (eg. ignition switch) may need additional electrical components to prevent overloading.

For extended periods of car inactivity, the most obvious recommendation was to disconnect the controller from the wiring plug at the back of it. (makes sense )

[Deleted]

Hi guys.
Having just joined, thought I'd stick my hand up for anyone who needs help with their Caravan undercarriage. I have worked for over a decade in the Trailer & caravan industry, particularly with undercarriage component supply, installation and repairs, I also still do work on caravans and trailer in my spare time...

The information you found is correct millard1399, the power wire required to fit the controller is ideally run directly to the tow vehicle's battery and not via an accessory wire. It should also be run through a 30Amp self resetting circuit breaker, fitted as close as possible to the battery.

[millard1399]

Ok, here's a question for the techo's...

I installed a Tekonsha Primus IQ controller in the car. The instructions say to set the controller at around 6.0 to initially test the caravan brakes. I found that I had to wind the controller up to 10 before the caravan brakes were "doing their bit" to slow the van/car down. All the brake pads and magnets were in the van when bought, and all appear to be in good nick. My brother adjusted the shoes during the replacement of the shock absorbers, and I'm thinking maybe he backed the adjuster off too many clicks?

What is a typical setting on the controller? My setting of 10 seems rather excessive when the max available is 13.

Any help appreciated.

cheers,
Al.

[viscount6116]

Gday Al
I've got a Tekonsha Prodigy 2 controller and I usually set mine at about 5-6 in the B1 (boost setting) and have found that if any higher it will lock the caravan brakes up
I think maybe a re adjustment of your brake shoes will solve your problem
Cheers Andy

[Deleted]

Hello Al,
I too have a Tekonsha Primus IQ that I have installed into my 1989 2wd Hilux - I towed my 21' Supreme from Toowoomba to Mackay on a 5 setting. If you just touch the brake pedal, you could feel the gentle brake response from the van.
During the entire trip, I didn't have to apply any more pressure to the pedal than normal 'non towing'.
As Andy suggests, maybe your van brakes need to be re-adjusted, or, if you have had the drums off, the shoes haven't bedded into their correct position before your last adjustment.
Another thing to look out for is too much voltage drop from the controller to the trailer plug - Over the years, I have found that 4mm cable is not up to the task, (sometimes measuring only 7 volts at the plug) and have always run 6mm cable, which has, on occassion improved braking ability by up to 20%.

Food for thought,

Regards,

Chris

[Deleted]

The size of the van can make a huge difference to brake performance for starters. Single axled brakes are rated for 1600Kg, but upwards of 1400Kg, they can start to get a bit wanting, and you'll find you need to have the controller set higher than someone else with the same controller but a lighter van. Also centralisation and adjustment are two critical factors. The proper way to adjust and centralise all in one is to loosen the four mount nuts on the backing plates, then crank the adjuster up tight, spinning the drum as you go. Once the brakes are locked, tighten the nuts back up, and loosen off the adjuster, only until the drum can spin by hand, but not freely. It shouldn't be stiff to turn, but you should still feel the shoes lightly rubbing against the drums.

4mm cable is the minimum required to run efficiently, but the length of the van, therefore the length of the cable, can have an effect on voltage drop, and joins must be spot-on as well.

[millard1399]

Thanks Andy, Chris, and yonnee. I did think my setting of 10 must have been way too high for "normal operation".

Now that you mention it, Chris, I did have the drums machined on both the brake shoe face and the magnet face, so what you say about the shoes not settling in yet might be a contributing factor. I'll check with my brother on how many clicks of the adjuster he did when he put the drums back on. From what I read on the internet caravan forums, there's quite a range of clicks that people tend to do - anything from about 8 to about 13 seems to be the popular range. Not being a car enthusiast, I have no idea whether there's a huge difference between 8 and 13 clicks anyway.

I'll chase it up and see what needs to be done. Maybe more kilometres to bed the shoes in better...or maybe an adjustment of the shoes...or maybe both?

The whole electric brakes system was rewired from battery to brakes with 6mm auto cable. Heaps better than the 0.75mm diameter bedlamp figure-8 cable that was there on the van originally.

I also installed an anderson plug connection on the towbar and bypassed the trailer plug. As well as that, every joint in the wiring system was soldered and covered with heat shrink.

cheers,
Al.

[Deleted]

If you've had new shoes and magnets, along with both faces machined, then they will definately need to "bed-in". Usually, one trip around the block, making a half-a-dozen or so aggressive stops from about 40-50Km/h with the manual over-ride should do the trick. You want to get them hot, but not smoking. They also shouldn't pull to one side either.

I've never adjusted them by the "number of clicks", and would never suggest it. Always by the feel of the drum spinning against the shoes.

[Deleted]

Hello Al,
Being a mechanic for over 30 years, I totally agree with yonnee, always adjust by the feel - if it feels right, it generally is right

Chris