My trailer brakes

dstig1 · Jul 13, 2011

I took them apart last week to see what they looked like. This is the first time I have done that since I got the trailer used a year ago (yeah I know...). These don't look so hot to me...

It looks like these are 12" brakes. I didn't measure the shoe width, but it looks like 12x2" is the common size.

I'm guessing I should just replace the brakes as a unit (all 4 - both axles, both sides). The inside of the drums look pretty good actually, so I'm thinking just the backing plates/shoes/mechanism as a unit needs to go. I really don't think they are functioning very well. I get some braking effect from the trailer, but I suspect I should be getting a lot more. I have no experience to compare it to, so I am just guessing.

Mark @ Everlast · Jul 13, 2011

Its definitely cheaper to replace the whole assembly. I wouldn't consider any thing less myself, having changed a few. I'd say that you might want to have the hubs mic'd too, even if they are smooth, they will have some wear. Trailer brakes aren't meant to have as much "meat" to deal with.

Diamondpilot · Jul 13, 2011

Yep, they need to go. Check with R&P Carriages for a great price.

By the way, they should lock up with the controller all the way up and with the controller adjusted properly they should pull the truck down when stopping.

Chris

schmism · Jul 13, 2011

Etrailer.com also has free shipping over $150 which entire backing plate assembly's are like $200 ea so you've got that covered.

etrailer.com - Electric Drum Brakes Trailer Brakes backing plates

that little oval shapped thingie at the bottom is the electromagnet that "sticks" to the drum with varying force as the voltage from the controller goes up/down.

As the e-mag sticks to the drum it is drug in the direction of rotation of the drum which in turn actuates the linkage to deploy the shoes against the wall of drum.

In short, if the e-mag doesnt look like its wearing against the surface of the drum... Your likely not getting any breaking out of that brake.

dstig1 · Jul 13, 2011

Thanks. Yeah I get the basics, but I don't think you pointed to the right item. This one is what I think I need:
12" Electric Brake Assembly, RH, 6K Dexter Trailer Brakes 23-106

I need to check out R&P and one other place also. Thanks for the tip Chris. "Lock up" is definitely something they are not doing...

tcartwri · Jul 13, 2011

We used to change everything out every two years, but that is doing a lot of mileage with a lot of weight. You should also examine the wheels for cracks, and the sidewalls of the tires at the bead for splits.

dstig1 · Jul 13, 2011

The PO put on new wheels and "new" tires (they are used truck tires, but not horrible for the moment). I'm not putting the kind of miles or abuse it sounds like you were. I pull it from storage to my land which is about 10 mi or so. Most of the trailer is "OK" at this point, but the brakes do need help, fer sure. I get some braking power but nothing like Chris said I should expect.

Diamondpilot · Jul 13, 2011

dstig1 said:
Most of the trailer is "OK" at this point, but the brakes do need help, fer sure. I get some braking power but nothing like Chris said I should expect.

I would check out your controller and your wiring. I have a client who had the same problem with a brand new 5th wheel. I figured it out after some research. What it was is the end was the manufacturer went cheap on the wiring. You should have 10GA wire from the plug on the trailer to the brakes. His had 16GA and it would not carry the current needed. He is still working on a law suit. Its basic electrical law. Too small a wire and the loss is such that the power needed to do the job is just not there.

Chris

RobertN · Jul 13, 2011

Nothing like a little IR loss to put a crimp in your day

Diamondpilot said:
Its basic electrical law. Too small a wire and the loss is such that the power needed to do the job is just not there.
Chris

dstig1 · Jul 13, 2011

I had to rewire it last year after I found out the brakes weren't even connected (and the lights were sketchy). I believe I used 12 or 14ga for the brakes. 16 or 18 for the lights from a roll of 4-wire siamesed cable. I didn't believe I needed anything much bigger than that based on what I saw at the time, though I knew I needed bigger wire for them. 10ga seems pretty extreme, as I didn't get the impression these were drawing anywhere near 20A, much less 30A. It isn't a lack of understanding of electricity - I know that plenty well enough for wire sizing fer sure - as long as I know what loads I am dealing with.

I will need to check as I really don't recall exactly what I used, though I know it was at least 14ga on the brakes. Does it really need 10ga? What do these things draw?

The controller is a new Prodigy using the F250 pre-wired harness and the Prodigy adapter to it. The controller was what alerted me that the brakes were not even connected at first (!) PO was a hack...

I think I will order up some brake hardware and then check out the wiring at the same time. If I need to, I can upgrade the brake wiring then.

Thanks,
Dave