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Thursday, March 14, 2019

Electric Brakes for Dummies made Simple

Electric brakes, should I buy them?........

"but I do not think I need electric brakes on my camper as it is lightweight."

This a comment that I get regularly.

Case 1:

Imagine going down a dirt road on a mountainside with 2-tonne of Landcruiser and 750kg unbraked camper (to keep it legal may be heavier).

Hit the brakes for something as simple as a corner and the Landcruiser slides on the dirt, pushed by your camper. You are into the bend in the road quickly still on the skids, and you take the foot off the brake and power around the corner. Done that heaps of times I bet.

OK, so you need electric brakes right at this point. Put a bit of rain on that same road, and it is 10 pm night-time, pitch black in the Daintree area. Very tricky to say the least.

Case 2:

Towing the boat trailer from the Hawkesbury back to Brisbane, halfway down Cunningham’s Gap and two semi-trailers side by side.

We are only doing 50klms, but the trucks are going 20klms.

This one scared me enough to put disc rotors and brakes on my boat trailer. I should have known better, and I should have done it years before, but I didn"t.

So What happened?

I ended up locking all four disc brakes on the Landcruiser, the front wheels were smoking, the boat was swaying, and I was heading to the wrong side of the road because I could not wipe off 30 km before I hit the back of the trucks.

Whether your trailer is legal or not legal, electric or disc brakes are a safety feature to get you and your family out of trouble on most occasions. Too hard? Too expensive? If you don’t know much about brakes on trailers, then read further for trailer parts help.

How electric brakes work

You need electric brakes on your camper if you are even thinking about long trips. If you need an axle fitted for you, chock up your trailer with an easy jack and remove your axle. We will fit up and test your axle in our workshop.

10-inch Electric caravan conversion kits are usually installed by the manufacturer or by trailer repair centres. The weld ring (supplied) fits 125mm - 139mm from the tip of the axle to the front of the weld ring. In many cases, the weld ring will fit on the last round machine surface and will press hard against the shoulder should (non-machined surface).

Axles up to 50mm Round or Square with Ford or Holden Bearings will accept electric brakes.

electric brake partsThe image on the left is all the parts you will need for your electric brake conversion.

The square plate in the middle of the picture is the most important part.

The weld ring is tig-welded within 0.1mm in the correct location otherwise; you will have overheating problems.

Tack weld the Brake Mounting Plate into position making sure it is square and concentric with the axle. If the weld ring is out of square or not concentric with your axle, then the Electric Brake shoes will wear unevenly thus reducing braking efficiency.

If the weld ring is out of square or not concentric with your axle, then the Electric Brake shoes will wear unevenly thus reducing braking efficiency.

What is the difference between new and old technology electric brakes?

New technology brake controllers have a proportional brake control unit as opposed to user control.

New brake controllers have a voltage readout to give the operator a great idea of the brake force being applied to the brakes. Older models like the Redarc Tow Pro Elite have no voltage readout.

This means, the harder you press the brake pedal, the harder your caravan brakes are applied.

Old technology brake controllers apply a preset force to the brakes only.

Click this link for the article on how to adjust your electric brakes.

Critical steps on brake adjustment are listed below.

4Critical Steps

If the weld ring is out of square or not concentric with your axle, then the Electric Brake shoes will wear unevenly thus reducing braking efficiency.

Once completed, you should not be able to see any part of the brake shoe outside the drum.

Note: Different axles use different mounting plates. 12-inch Electric brakes also use different mounting plates. I have covered the popular models here.

Fitting the Electric camper brakes is a matter of tightening four nuts at the back of the Brake Mount plate and then mounting 10-inch Drums and bearings.

Need help about now? Call our professional sales team on 07 33483822

There are three types of weld ring.

  • Rings that have a 44mm round hole and fit slimline 45mm to 50mm axles.

  • Those that have a 39mm round hole and fit 39mm and 40mm axles.

  • Some that have square holes and fit over marine bearings.

Confused, call us or bring your axle into our workshops for a fit up.

10-inch Electric brakes have a rating of 1600kg when using 13 – 14 inch Ford or Holden wheels and 1450kg when using 15 – 16-inch wheels. If you want 1600kg on 15 – 16-inch wheels then you will need to go to 12-inch Electrics and 2-tonne drums.

Electric trailer brakes how cabling works

Remember to use 6mm cable or above when wiring your single axle electric braking system.

Also, use 6mm cable or above when wiring your tandem axle electric braking system. Wire down each chassis rail rather than access your axle.

Often 3mm or lower cable is used. These sizes are inadequate or marginal and provide sufficient voltage drop from your battery to cause your brakes to work at something lower than 100% capacity.

Example, when using 3mm cable, your controller will be wound up to the maximum voltage.

A voltage drop occurs at the point of the electric brakes causing you to have only 50% braking capacity. Install 3mm cable or larger, and you see a much better result with minimal voltage drop and maximum power at your electric brakes.

It is wise to have your trailer re-certified by an approved inspection station after any DIY work.

[caption id="attachment_6340" align="alignleft" width="300"]Damaged Electric magnet caused by rough dirt roads. Damaged Electric magnet caused by rough dirt roads.[/caption]

Electric Magnet Comparison

The difference between Off Road, Highway and Budget Electric Brakes is:-

(a) Budget Electric Brakes are ideal for tandem trailers, horse floats and other such trailers performing short-haul duties.
(b) Standard Highway Electric Brakes are common on caravan and campers. Brake shoes and magnets are of a higher grade to dissipate heat generated by long haul on Australia"s highways.
(c) Off-Road driving can get hot and dusty. Standard duty electric brakes can get extremely overheated because dust, sand, etc. build up inside the electric brakes. Off-Road electric brakes have been designed to cater for the effects of off-road travel. Better shoe material and anti-rattle electric magnets make off-road brakes a must for the serious traveller.

Off-Road Magnets have plastic inserts to help prevent magnet wear caused by road corrugations. The magnets rattle on the magnet actuating arm causing the magnet lever arms to wear and fail if electric brakes installed with standard electric backing plates.

Read our Caravan Electric Brakes FAQ here

BASICS (legal stuff)

  • Trailers with a total laden weight under 750kg do not need brakes.

  • Trailers with a total loaded weight between 750kg - 2000kg need any brakes on one axle. Disc brakes, Mechanical drum brakes and electric brakes are common.

  • Trailers with a total laden weight between 2000kg - 4500kg need electric brakes or electric/hydraulic on all axles plus a breakaway kit.

  • A trailer is any vehicle that has wheels and is connected to your tow vehicle and towed.

5 Stud Lazy Hub

Zero to 750kg Trailers

Small trailers up to 750kg, do not need brakes.

Australian made Lazy Hubs can be purchased here from $24.75 by clicking the image.

Always buy your hubs from reputable dealers like Al-ko and a few others, you do not want hub and flange separation from these poor quality hubs below.

750kg to 2000kg Trailers

  • 10-inch Disc rotors are the cheapest type of braking system you can install. You will need to weld onto your axle a caliper mounting plate, and the hard part is over. When buying a new trailer or caravan axle, ask your retailer to arrange for the caliper anchor plate to be installed for you.

Caravan and trailer disc brakes engage when override coupling activates during braking by the tow vehicle. Simply, when the tow vehicle brakes, the trailer pushes into the tow vehicle and enables the override assembly pulling the cable attached to your disc callipers. There is a small time delay with all override couplings. Commonly used on boat and tandem trailers. Not recommended for camper trailers except if you are doing a lot of sandy beach work.

Braking Systems

  • 9-inch Mechanical Override brakes work the same as disc rotors except you need to weld a ring onto the axle to hold the brake backing plate. A little more expensive than disc rotors and used by small caravans and trailers.

  • 9-inch Hydraulic Brakes work on an override assembly as above except the cable is replaced with hydraulic lines. Mainly used on older caravans and tandem trailers.

  • 10-inch Electric braking systems use a four-hole weld ring to secure the 10-inch electric-backing plate to the axle. Once the backing plate is attached to the weld rings, the drum is then fitted and tightened with the axle nut. 10-inch Electric brakes are suitable for any axle up to 50mm in diameter. When tightening your axle nut, tighten as much as possible then back of 1/8 turn.

  • 12-inch Electric braking systems suit 50mm and above axles. Loads over 1600kg on a single axle will require 12-inch braking systems.

Maximum Axle Ratings

Maximum axle size for this system is 50mm. Ratings are 750kg/39mm Round Axle, 1000kg/40mm Square axle, 1500kg/45mm Square Axle.

Maximum Tandem set-ups for 45mm Square and round, rated at 2900kg for 10-inch Electric Brakes. Over 2900kg on a tandem, and you will require 12 inch Electric Trailer Brakes.

2900kg - 4500kg need 12-inch Electric Brakes on 50mm to 65mm Round depending on weight requirements.

Once you have decided what weight you wish to carry, then it is simply a matter of selecting the axles, brakes and spring set-ups.

What is the most common setup? Electric brakes on campers and caravans by a long margin.

Correct Axle Setup

Question: I am building a trailer, and I want a complete set-up under 750kg to go to Cape York.
Answer: Go for a 45mm Round axle rated at 1450kg with Off-road springs with 6 Stud lazy hubs. You can install brakes later if you feel the need. A setup with a lower rating will give you trouble because you will almost certainly be carrying more than you think. Water, Fuel, Food, gear, etc. will add more than you think to your total trailer weight.

Weighbridge Certificate

Question: My boat trailer is about 2 tonne tandem with 50mm Square axles and brakes on all axles which do not work anymore. I purchased the trailer and boat cheaply, but the trailer needs work. I think I just need disc brakes on one axle because the weight is pretty close to the limit.

Answer: Together a trailer and a boat will almost certainly weigh over 2-tonne, and you will need to get a weighbridge certificate. This certification is required to get it registered in your name, so I suggest that you weigh the rig so you are not throwing money at a brake set-up that you may be required to change later. You’ll save a lot of money in the long run by having the right set-up the first time around.

Electric Brakes not Working

Question: I purchased a set of Electric brakes and had them installed. My caravan brakes did not lock the wheel when the brake controller turned to full power.

Answer: (a) Check wiring to the electric brakes and make sure the wiring is 3mm for single axle and 5mm for tandem axles. You may have a problem with voltage drop using smaller cable sizes.
(b) The brake shoes may not have bedded themselves if you have not travelled 100klms – 150 km and readjust the brakes.
(c) Apply 12 volts directly to the brakes; you will not be able to move the wheel. There may be a problem with your electric brake controller if the direct method works well.
(d) Most trailers do not incur wheel lock except with an empty load.
(e) A voltage drop occurs when you use too much cable. Example, an axle wired across the axle. Two ways to fix. (a) Run down each chassis rail and wire to each brake. (b) Run a larger size cable across the axle.

Read our Caravan Electric Brakes FAQ here

Hot Electric Brakes?

Question: My brakes are getting hot even when the brake shoe adjustment is loose, and the electrics are disconnected.

(a) Remove drum and inspect shoes. One or both shoes may be out of the centre. Re-centre shoes and re-install drum.
(b) Reinstall the brake drum, adjust shoes tightly until there is no more adjustment. Then wind the adjustment lever 13 clicks. The factory setting is 13 clicks from the locked position. The main reason electric brakes get hot when first installed is the shoes are not aligned correctly and rub the drum on one end of either or both shoes.
(c) Another reason is Chinese Bearings getting hot, change them to Japanese.

Correct Caravan Bearings

Question: I purchased my caravan bearings from a reputable shop. How do I know if they will cope with long trips?

Answer: We do not support anyone brand of bearing. The word JAPAN must appear on the bearing to ensure you have a good long haul bearing. If the word JAPAN does not on the bearing, I will not use them.

Electric Brake controller not Working

Question: I just installed my tandem electric brakes using a chassis mounted controller, but my brakes are locked on.

Answer: Once your brakes are under load, your brakes will perform like new. If your trailer is empty, your brakes are likely to lock on some road surfaces.

Furthermore: Advice on this page is obtained from some sources and is not necessarily our own.

Finally, usage of any text or images on this page is forbidden by law unless you provide a link back to this page on your page. You may copy and paste text but not pictures or video.

If you found this article informative, feel free to leave a comment.

© Steve Wotherspoon 3rd May, 2014

Electric Brakes made Simple

Monday, March 11, 2019

2t Bearing Kit suit Alko - Japanese

2t Japanese Caravan Bearing Kit for long hauling is a must for caravans and boat trailers that are fitted with Al-ko drums.

In addition, Al-ko international Pty Ltd offers its customers a wide range of running gear including axles and also, a wide range of accessories to suit the trailer, caravan and RV markets in Australia.

Couplemate manufacturers, markets and distributes a comprehensive range of high quality running gear including axles, brakes and suspension products.

Bearing failure is all too often caused by lack of maintenance or checking bearings before travelling long distances. Even the best 2t bearings need checking after long rests between trips.

The consequence for not checking your bearings is a costly disaster. Sorry to be blunt.


Important information for Marine Seals.

Marine seals are designed to rotate inside its metal retaining ring.

Friction can create heat up to 100 degrees C.

It is essential you grease this seal around the outside ring of a marine seal, with a liberal amount of grease. The seal is then placed onto the axle, not into the hub.

A dry marine seal causes excess heat.

2.25t Japanese Caravan Bearing Kit

2.25t Japanese Marine Bearing Kit

Bearing maximum capacity is listed below

It is wise to remove the old bearing cups when replacing bearings. Cups and races are subject to wear and tear. Carbon black in your grease or black grease is a sign of bearing wear. Immediately replace bearing cups and races.

Low-quality bearings have poor coatings and low tolerances.

Use high temperature bearing grease for use at high speeds.

Links to similar bearings from our quality running gear range here
How to Correctly Grease a Marine Bearing Seal.

2.25t Japanese Caravan Bearing Kit

Friday, March 8, 2019

2t x Lazy Hub | Al-ko | Dexter

2t x Lazy Hub | Al-ko | Dexter studded to Landcruiser or 8 Stud configuration. Note: Dexter Hubs are non-genuine.

Here is a great article on how to install a marine seal correctly.

Couplemate carries a good range of trailer hubs with a galvanised finish. Give us a call if you require and galvanised lazy hubs not listed here.

Suits the following PCD.

  • 2t or 3t L/cruiser (6 x 139.7 PCD 1/2 studs) (5 x 150mm 9/16" studs)

  • 2t or 3t x 8 Stud Configuration

We recommend Japanese bearings for high-speed highway use and longevity of your bearings.
  • Check your bearings yearly for water ingress or carbon black deposit in your grease.

  • Carbon black means bearing wear so they will need replacing.

  • The carbon black comes from wear on the casing of the bearings.

2.25t Al-ko Caravan Bearing Kit

2t Dexter Bearing Kit

You are likely to need Dee Shackles on your caravan. Read this to help select the correct size of Dee Shackle.

Why caravan and boat trailer bearings fail.


2t x Lazy Hub | Al-ko | Dexter

Electric Brake Magnets

This Caravan Electric Brake Magnet is suited to all electric brake systems except older round magnet brake systems.

How to check magnet wear

  • Check the four small holes on top of the magnet.

  • These holes are warning indicators that display magnet wear.

  • If there are no holes or less than 4 holes.

  • Then the face of the magnet hole has worn then it is time to replace the magnet.

Key Features

  • Wear holes are at 3 pm, 6 pm, 9 pm and 12.

  • Magnets draw approximately 3.2 amps each

  • Wires can be connected either positive or negative.

Once worn, copper begins to become exposed, subsequently, an open electric circuit will render the brakes inoperable.


  • New magnets need to be bedded into position before 100% of braking is achieved.

  • The magnet face is a shiny finish.

  • This finish needs to be scuffed up during the initial stages of breaking before your magnets become 100% effective.

Why can’t I run the electric cable across my axle?

Click this link to check the correct cable size for the installation
  • Run down each chassis rail = 6mtr @ 6.4 Amps per pair of magnets = 5.62mm cable size

  • Run down the chassis trailer (inside) = 6 meter + 2 mete (8mtr) @ 6.4 Amps per pair of magnets = 7.5mm cable size

To escape voltage drop, run the cabling down the chassis rail.

We recommend using a Tekonsha Primus or Prodigy or a Chassis Mounted brake controller (Qld and NT Only)

For chassis mounted brake systems, do not wire electric brakes into the brake light circuit. Incandescent brake light circuits provide 21 watts of power and can be used as a control circuit only for chassis-mounted controllers. If you have purchased a caravan or camper with brakes wired into the brake lights, then the braking system is working at less than 25% of their efficiency.

All brake controllers are wired from the battery. In most cases, the brake controller has a relay that is powered by the brake lights.

If brake lights are used to power brake controllers, significant voltage losses will occur resulting in brakes operating less than 25% capacity.

It is permissible to wire chassis controllers from the onboard battery in the caravan because this battery is often powered from the main car battery.

OffRoad Magnets

10-inch Al-ko OffRoad electric brake magnet (genuine) to suit all Alko and some Dexter electric backing plates.

The lifespan for offroad magnets greatly exceeds the life cycle of standard offroad magnets.

Purchase electric backing plates here.
  1. 10 inch Dexter Electric Brake Kit

  2. 10 inch Dexter Offroad Electric Brake Kit

  3. 10-inch Premium Electric Brake Assembly

  4. 10 inch Premium Offroad Electric Brake Kit

  5. 12 inch Premium Electric Drum Brake Kit

  6. 12-inch Premium Offroad Electric Brake Kit

  7. 12-inch Dexter Electric Backing Plate Brake Kit

  8. 12 inch Offroad Dexter Electric Brake Kit

Why do offroad magnets last longer?

  • The steel magnet arm causes the steel magnet on a standard highway magnet to rattle causing wear.

  • The plastic insert on the Al-ko off-road magnet prevents the same wear under the same conditions.


The 10-inch Alko OffRoad Electric Brake Magnet has been extensively tested in typically harsh Australian conditions and has proven that it is durable, reliable and will not let you down even in the toughest terrain.

Difference between Highway and Offroad Magnets

  • Electric Highway brake magnet uses a CLIP to hold the magnet into position on the magnet arm.

  • Off-Road Electric brake magnet uses a RUBBER BAND to hold the magnet into position on the magnet arm.

The rubber band breaks on first use and relies on the return spring to hold the magnet.

Left side and right side magnets are not interchangeable.
  • The left side is the passenger’s side

  • The right side is the driver side

The purpose of the rubber band is to hold the magnet into position to allow drum installation onto the axle profile, then tighten.

If the magnet needs replacing or upgrading from a standard magnet, then it may be wise to replace the whole backing plate. 

Worn Offroad Electric Brake MagnetsComplete 10″ electric backing plate prices here.


The magnet in the third image was a standard magnet used on corrugated.

All 10-inch Alko OffRoad Electric Brake Magnet have a plastic insert that prevents the magnet arm causing damage to the magnet from corrugated road vibrations. (image 2)

As a result, Al-ko offroad magnets continue to show no wear tens of thousands of miles on corrugated roads.

Safety Chain Checks

Important safety check or tandem wheel caravans. With the chains attached to your vehicle, push your caravan back to the extremity of the chains.

Finally, did the pin on your breakaway kit disengage?

If not, read this important article on adjusting safety chain lanyards.

12" Electric Brake Magnet - Standard

All 12-inch electric magnets have white cables. If the magnet has green cables, they are 10" magnets.

12-inch Electric Brake Oval Magnet are suited to all 2t electric brake systems except older round magnet brake systems.

Purchase 12-inch replacement parts below.

Dexter 12" Brake Magnet

Dexter 12″ Magnet 2t suit left hand and right-hand dexter electric backing plates.

However, if you require 12" offroad Dexter Magnets then you need to purchase the Alko offroad magnet and adjust your magnet arm to suit the magnet.

In Addition, Al-ko does not make 12" Dexter Offroad magnets.

Finally, purchase 12-inch replacement parts below.

Electric Brake Magnets