Electric brakes for dummies

notfarnow · 06-13-2007, 07:19 AM

I just bought a 20' car trailer, rated for 4000#. It's 200 miles away, and I don't think my Jetta or Samurai are up to the task of towing it home.

Through a series of very lucky coincidences, I met a guy on Monday who lives down the road from me, and is driving that way to deliver a sailboat. He's going to pick up the trailer for me on his way home on Thursday.

Anyhow, the trailer has "newish" electric brakes. Electric brakes fall into a category of Things I Never Wanted to Learn About, along with 2 stroke engines and automatic transmissions.

I've been looking online, trying to find a basic "how it works" with diagrams and a basic description of how it works.

I've been looking at parts schematics but I still don't understand who puts which on the whatnow, knowhadimean?

legion · 06-13-2007, 07:25 AM

It's the actual brake controllers that I am more interested in.

notfarnow · 07:36 AM

Yeah, questions about the controller:
-Are they universal, i.e. will any controller work with any electric brakes trailer?
-Does the controller have to be wired permanently to the vehicle, or is it something that you can move easily from vehicle to vehicle?

The trailer's primary function will be to launch my sailboat each season. I'm wondering if I there are components I should remove before submerging them in water. The launch is only one block away, and I'll be using my samurai. I won't need electric brakes for that. I mean really... what could possibly go wrong?

VINMAN · 07:41 AM

Brake controllers are pretty much universal. Most are hard wired to the vehicle. There might be a few that have modular wiring. As far as removing components , if its a boat trailer, no reason too. Just wash everything out good. I installed a brake flush assembly on mine. you hook a garden hose up to it top flush it out.

How big and whats the # of the sailboat?

notfarnow · 06-13-2007, 07:46 AM

Thanks Vinman!
BTW, I should also thank you for a post you made a while back about cooking pizza on the BBQ. I've been doing that 3-4 nights a week while my wife is away. No dishes!

Quote:

Originally posted by VINMAN
As far as removing components , if its a boat trailer, no reason too.

It's actually a car trailer, so does that apply? I'm going to make a low cradle for my boat that sits on it. My boat only has an 18" draft, so this will work like a charm.

Quote:

Originally posted by VINMAN
Just wash everything out good. I installed a brake flush assembly on mine. you hook a garden hose up to it top flush it out.

Sounds like a slick setup. Is that something you bought, or something you rigged up?

Sailboat is 22', 3200#, 18" draft with the keel up

legion · 06-13-2007, 07:49 AM

Boat trailers are designed to be submerged, car trailers are not. Makes me wonder what problems you might have.

notfarnow · 08:01 AM

Quote:

Originally posted by legion
Boat trailers are designed to be submerged, car trailers are not. Makes me wonder what problems you might have.

+1

Rust, for one. To its advantage, it's made of C channel instead of box sections, so I should be able to rinse it really well and keep it protected.

It's very overbuilt and using heavy C channel; built like a brick $hithouse. I sent someone out to have a look & snap pictures.

I'd post a pic but it's so ugly I wouldn't dare. My wife is going to have a fit when she sees it in the driveway. I'm hoping I can spash a coat of paint on it before she gets home in two weeks.

legion · 06-13-2007, 08:00 AM

I was thinking that maybe the brakes and signal light wiring on submergable trailers are designed differently. You may need to put some components from a boat trailer on your trailer to make it work.

GDSOB · GDSOB's Garage

If you are going to submerge your car trailer, unplug the lights and brake connector before hit the water. Check and see if the water has drained out of the lights before you plug back in.Most boat trailers have hydraulic brakes.

If in salt water, rinse the brakes throroughly. They rust solid if you don't. Also think about repacking the wheel bearings or use bearing buddies to displace the water.

oldE · 06-13-2007, 08:52 AM

Jake,

The type of electric brake you have pictured above works like this:

When you touch your brakes, (enough to light your brake lights) the brake controller picks up the signal and uses it to pass a higher amperage current through a wire to the electro-magnet inside the trailer's brake drum. This magnet, when energized, is attracted to the brake drum, which, if it is rotating, pulls the lever arm the magnet is attached to with enough force to cause a short lever on its other end to spread the shoes and provide some braking force.
The controller can be adjusted to provide a 'sharper' response or more or less braking power to tailor the action of the brakes to road & load conditions. Usually, there is a manual actuation as well, through a sliding switch on the unit.

Les

VINMAN · 06-13-2007, 09:05 AM

Jake, glad youre enjoyin the pizza!!

Like Chris said, boat trailer lights are design to be submersible. Either they are totally water tight, or made with provisions for the water to drain out. You will definately run into problems with regular lights. I'm changing all mine over to LED lights.

As far as the brake flush, yeah you can buy it. in a marine store or trailer supply. But being the cheap bast@rd I am, I made it myself.

Basically it just a set of hoses teed off to each backing plate, that I hook a garden hose up to. I drilled a hole through the top of the backing plate to stick the line through.

notfarnow · 06-13-2007, 10:25 AM

I have been trying to get a boat trailer for ~2 yrs, but there are no used ones to be found around here. Importing a trailer from the US is a nightmare. I decided to get a robust flatbed, as long as it wasn't made with box section. This was I'll have a dual purpose trailer for fetching cars and other large broken objects. My wife will be pleased that my capacity to accumulate has increased substancially.

Quote:

Originally posted by oldE
This magnet, when energized, is attracted to the brake drum, which, if it is rotating, pulls the lever arm the magnet is attached to with enough force to cause a short lever on its other end to spread the shoes and provide some braking force.

Gotcha, thanks! Question: Why only if it's rotating?

Quote:

Originally posted by VINMAN
As far as the brake flush, yeah you can buy it. in a marine store or trailer supply. But being the cheap bast@rd I am, I made it myself. Basically it just a set of hoses teed off to each backing plate, that I hook a garden hose up to. I drilled a hole through the top of the backing plate to stick the line through.

Good to know, because I'm a cheap ba$tard

How long do you run the water for? Do you use any kind of nozzle in the drum, or just let it fill up & drain out?

Quote:

GDSOB
Also think about repacking the wheel bearings or use bearing buddies to displace the water.

Great tip. Yes, I'm concerned about the bearings... haven't been touched in 3 years. I'll throw bearing buddies in when I check the bearings.

Quote:

legion
I was thinking that maybe the brakes and signal light wiring on submergable trailers are designed differently. You may need to put some components from a boat trailer on your trailer to make it work.

Good point. I was thinking about setting up all the electrics so they could be unclipped from the boat. I've seen a couple like that and it allows them to back right in the water without getting the lights or wires wet.

If I set the brakes up with Vinman's Budget Brake FlushTM, I should be good to go.

I do wonder if it would be worth my while to remove the brakes altogether, and then reinstall them if I ever end up needing to use the trailer on the road.

URY914 · URY914's Garage

My trailer controller came with a "pig tail" that connected directly to my pre-wired truck connector under the dash. I bought it with the trailer towing package. I'm able to unplug the controller when not towing the trailer. Works like a charm.

GDSOB · GDSOB's Garage

Gotcha, thanks! Question: Why only if it's rotating?

The magnet w/friction face is drawn to the armature, and the rotation causes the lever arm to pivot and spread the shoes and activate the brake. It works in reverse, but usually not as powerful.

notfarnow · 06-13-2007, 11:05 AM

Quote:

Originally posted by GDSOB
Gotcha, thanks! Question: Why only if it's rotating?

The magnet w/friction face is drawn to the armature, and the rotation causes the lever arm to pivot and spread the shoes and activate the brake. It works in reverse, but usually not as powerful.

Ahhh! Now it makes sense! Thanks

djmcmath · 06-13-2007, 02:39 PM

The trailer braking system that a friend of mine had was all set up in the trailer tongue. The principle was simple: apply the brakes in the towing vehicle; the trailer, with no brakes yet applied, pushes forward into the truck, applying forward pressure at the tongue; the forward tongue pressure applied the brakes on the trailer, which slowed it down, relieving the pressure on the tongue, which relieves the brakes.

He was thrilled with the system -- no problems with tuning the brake response to the load, making sure that the trailer brakes at the same rate as the truck, etc -- it's an intuitively managed equilibrium.

legion · 06-13-2007, 05:17 PM

djmcmath, that system is known as "surge" brakes. U-haul uses it on all of its trailers with brakes.

notfarnow · 06-15-2007, 05:01 AM

Got my ugly-a$$ 20' trailer last night. Sweet.

I need to hide it in the garage before my wife gets home.

The guy who picked it up for me talked me into pulling the brakes and changing the axles. He's going to get a set of axles that can be set a bit lower, that have "bearing buddie" and use 13" tires. That will make it easier to launch with. He's going to do the work in exchange for the axles that are on there now.

His reasoning is that the brakes will be rusty and seized within a year or two, because I won't be using them and they'll be getting wet.

nota · 06-16-2007, 06:05 AM

agree IF you will only go a block and never ever take a road trip with the trailer
BUT you now have a great trailer to fetch P cars and other big stuff on and may want to do that someday
keep the axles and brakes

if saltwater or a deep keel on the sailboat
I would make a launch cradle with wheels or rollers on the cradle
and never dunk the trailer to save rust problems
just roll to the waters edge and dunk the wood cradle
with the boat on it off the trailer
a wood cradle should float esp with air filled wheels and no steel
making retreaving it a snap use SS or bronz bolts
use weights to sink it for fall return to land hauling
btw most class boats will have a ship cradle diagram on line somewhere to guide your build
wheel/rollers to suit your ramp use if smooth or ruff

stomachmonkey · 06-16-2007, 06:23 AM

Quote:

Originally posted by notfarnow
snip..... The launch is only one block away, and I'll be using my samurai. I won't need electric brakes for that. I mean really... what could possibly go wrong?

Lots!

May come a day when you are all alone trying to drive the boat onto the trailer and the trucks brakes start to give. You'll sit there revving the snot out of the boat trying to keep the truck from submerging. At some point you'll come to the conclusion that you are either going to blow up the motor in the boat or run out of gas and the truck is done for anyway.

Just a possibility, not like it's ever really happened to anyone I know