Electric Brake Adjustment

[Beltzington]

I'm rewiring a newly purchased used dual-axle trailer with brakes on all four wheels and I trying to determine how a single line vehicle control wire (the blue-one) controls multiple brakes. It would seem any difference in wire impedance or the brake shoes being out of adjustment would result in significant braking performance at each wheel. Will the normal brake auto-adjusting mechanism compensate for the electrical differences between the controller and each individual wheel or is there an accepted procedure? As usual, I should think less and do more but as the scorpion said "it's my nature." TIA

 

[Willl]

Unless you have some serious connection problems, the minute small differences won't be noticed.

Trailer brakes are not that precise anyway, I wouldn't expect Porsche type performance from them.

 

[Diamondpilot]

There are differences. You just have to live with it. None I have ever seen are auto adjusting. You need to adjust them at 1,000 miles then about every 3,000 or so manually.

Chris

 

[2COR517]

I have a one year old Ringo dump trailer with a similar problem. The left front locks up before the others start to do anything at all. Maybe someone could give a quick walk through of how to adjust electric brakes. I looked around here for a while but couldn't find anything.

 

[aczlan]

How to Adjust RV Trailer Brakes is a pretty good how-to on adjusting RV brakes, the procedure is the same for other electric trailer brakes as well.

Aaron Z

 

[Bird]

As far as the adjustment goes, this article describes how it is done and following these instructions will get all wheels adjusted the same. Now that might fix the problem of one locking up ahead of the others, but when one locks up ahead of the others, I'd be pulling the drums off to have a look. Has a grease seal leaked grease on the brakes, in which case, new brake shoes are needed. Or has a broken or shorted wire caused the other wheels to not be working? If one wheel works differently from the others, how did one get adjusted differently from the others? In other words, I'd sure suspect the problem to be something other than adjustment.

 

[Egon]

In our area a yearly trailer inspection is required. This means the brake drums must be pulled to have a look at the brake shoes and other components. That means the bearings are grease once a year and the brakes get a professional adjustment once a year. It saves on doing it oneself unless you have a high mileage/year trailer.

 

[Beltzington]

Thanks all, the instructions help. It has been many years since I have needed to adjust drum brakes.

Has anyone heard a logical reason for the ridiculous trailer wire-code standards? Let's see; green is right-turn lights unless it is the marker lights in which case black might be ground unless it is positive which should never be connected to the white because it could short circuit the red wiring in your vehicle.

 

[SnowRidge]

Thanks all, the instructions help. It has been many years since I have needed to adjust drum brakes.

Has anyone heard a logical reason for the ridiculous trailer wire-code standards? Let's see; green is right-turn lights unless it is the marker lights in which case black might be ground unless it is positive which should never be connected to the white because it could short circuit the red wiring in your vehicle.

You really don't have to follow that or any other color code. As long as your connectors have the correct functions wired to the appropriate pins, you are good to go.

 

[Willl]

Has anyone heard a logical reason for the ridiculous trailer wire-code standards?

Believe it or not this same color code goes all the way into semi trailer wiring. Only diff is blue is aux.

 

[KICK]

Has anyone heard a logical reason for the ridiculous trailer wire-code standards? Let's see; green is right-turn lights unless it is the marker lights in which case black might be ground unless it is positive which should never be connected to the white because it could short circuit the red wiring in your vehicle.

never found it all that ridiculous or complicated.

gReen is RIGHT

yeLLow is LEFT

It would seem that they had to pick something, that was what they picked... they coulda went to an alphanumeric type system that cross referenced to a color code but why? its a trailer. it usually has 4 wires.

 

[2COR517]

Thanks for the info. I will give it a try. I suspect I will have to pull the drums and see what's going on in there.

 

[Beltzington]

That's what I thought -Green Right - Yellow Left
But then I read this:

Marksrv.com 7 way wiring diagram page

My trailer has a 7-way connector, as does my Jeep. Obviously, this can be sorted out with a volt meter I just found the differences frustrating.

 

[SnowRidge]

That's what I thought -Green Right - Yellow Left
But then I read this:

Marksrv.com 7 way wiring diagram page

My trailer has a 7-way connector, as does my Jeep. Obviously, this can be sorted out with a volt meter I just found the differences frustrating.

That's a handy reference link. It should help a lot of folks. Thanks for posting it.

 

[john_bud]

It's best to adjust the brakes AFTER you run them for a while. You may have some surface rust that makes the brakes grabby. Burn that off, then adjust.

 

[Bird]

It's best to adjust the brakes AFTER you run them for a while. You may have some surface rust that makes the brakes grabby. Burn that off, then adjust.

I didn't think about that, but that sounds like good advice.

 

[SnowRidge]

It's best to adjust the brakes AFTER you run them for a while. You may have some surface rust that makes the brakes grabby. Burn that off, then adjust.

Yep, my 20 ft trailer's brakes always used to grab the first few applications, if I hadn't used it for awhile. I've learned to set the controller very low and brake manually with it as I come down the drive. I do the same thing for a few hundred feet on the road against engine power, then put it back to its normal setting. That cleans the brakes up, and I don't get any more unwanted lock-ups.

 

[Beltzington]

Another Question - My trailer electric brakes have a red and black wire coming from each hub. I am guessing the red should go to the blue brake controller and the black to ground? However since the black on the 7-way connector is a constant positive 12vdc I thought I should ask.

 

[Diamondpilot]

The black on the trailer wire (red/black) should go to the ground. I like to run the grounds all to one central point on the trailer. Eliminates a lot of problems.

Chris

 

[SnowRidge]

Another Question - My trailer electric brakes have a red and black wire coming from each hub. I am guessing the red should go to the blue brake controller and the black to ground? However since the black on the 7-way connector is a constant positive 12vdc I thought I should ask.

The brakes are unaffected by polarity. It doesn't matter which way you hook them up. A lot of trailer brakes have both wires the same color.