Good Sam Club Open Roads Forum: Tech Issues: Replacing Elec brakes
Open Roads Forum Already a member? Login here.   If not, Register Today!  |  Help

Newest  |  Active  |  Popular  |  RVing FAQ Forum Rules  |  Forum Posting Help and Support  |  Contact  

Search:   Advanced Search

Search only in Tech Issues

Open Roads Forum  >  Tech Issues

 > Replacing Elec brakes

Reply to Topic  |  Subscribe  |  Print Topic  |  Post New Topic  | 
Page of 2  
Next
Jethroish

Scottsburg, IN

Senior Member

Joined: 05/31/2001

View Profile



Good Sam RV Club Member


Posted: 12/29/21 07:00pm Link  |  Quote  |  Print  |  Notify Moderator

Could not find anything on this here.
I have a horse trailer with dual 7000# axles. I suspect the brake magnets have weakened. Visually they appear good, but with the brake controller set at the highest setting, only one wheel will lock up on the gravel driveway. Trailer is about 8000# empty. I have adjusted the brake shoes out and they lock up with the trailer off ground.
I know things wear out and eventually need replacing.

Anyone here ever have a similar experience? Did you change out the brakes with a full assembly that included new magnet?

The brakes on the trailer are original (2015 model). Rough guess is the trailer has been towed approximately 60,000 miles in 6 years.


Don't let your work become your life.
2018 RAM 3500 Dually 4x4 crew cab,
2015 Shadow Select 4 horse LQ w/slide out
2021 Jayco JayFlight SLX 264BH

Gdetrailer

PA

Senior Member

Joined: 01/05/2007

View Profile



Posted: 12/29/21 07:44pm Link  |  Quote  |  Print  |  Notify Moderator

Are you sure you actually were tightening the brakes?

Did you use the little peep hole in the back of the backing plate?

If so, you can easily back off the brakes instead of tightening them.

Might wish to pull the drums and get a good visual on the condition of the brakes, you can measure the lining to makes sure you have sufficient brake lining. In my state you need the thickness of a nickle to be considered legal any thinner and they must be replaced.

If you are using EZ lube axles or Bearing buddies, you could also have grease buildup that bypassed the inside seal and that grease can get on the brakes and the magnet..

With the drums off, you can now easily adjust the star wheel so the drums just slide on with a slight resistance. Temporarily add the outside wheel bearing and hand tighten it and give the drum a spin. Drum should have a slight resistance, you should here the brakes touching the drum as you turn it, if it stays turning the brakes are not adjusted out correctly. If drum is hard to turn, then you have the brakes set too tight.

Depending on the age of your trailer, you might wish to rework all of the brake wire connections before replacing brake parts. Not unusual for trailer builders to use splices not suitable for outdoor use. The connections get damp, corrode corrosion on the wires in the splices acts like an insulator and now you have weak brakes.

As far as replacing the brakes, yes, generally the most cost effective and easiest way is to replace the entire backing plate. This gives you all new parts including magnets.

Electromagnets generally do not "get weak" with age, they do wear on the contact surface so you do need to inspect the magnets contact surface to make sure the windings have not been exposed.

ajriding

st clair

Senior Member

Joined: 12/28/2004

View Profile



Posted: 12/29/21 07:54pm Link  |  Quote  |  Print  |  Notify Moderator

Everything he said....

Magnets do wear and do go bad without wear, but at only 6 years old I suspect they are either worn or other issues exist.
Magnets are cheap to try. Trying is not the worst solution.

The grease on the brake pads sounds likely since it locks up in the air but nothing on the ground.

Check wires. Trailers are notorious for having terribly done wiring for brakes.

Check that the mechanism physically works (it should that you said it locks up in the air).

etrailer dot com has a wealth of info and also great prices on everything you will need.

time2roll

Southern California

Senior Member

Joined: 03/21/2005

View Profile



Good Sam RV Club Member


Posted: 12/29/21 08:39pm Link  |  Quote  |  Print  |  Notify Moderator

Not that expensive to replace the complete assembly. For superior braking I recommend going to disks.


2001 F150 SuperCrew
2006 Keystone Springdale 249FWBHLS
675w Solar pictures back up

Gdetrailer

PA

Senior Member

Joined: 01/05/2007

View Profile



Posted: 12/29/21 08:53pm Link  |  Quote  |  Print  |  Notify Moderator

time2roll wrote:

Not that expensive to replace the complete assembly. For superior braking I recommend going to disks.


$2K+ parts plus labor for disc conversion..

Look, the drums obviously worked well for the OP in the past, with a little detective work and not much more than $250 the OP can rebuild their existing drum system to work just as well as it did when new.

Unless the OP was having brake fade as an issue (which does not seem to be the case) how about sticking with troubleshooting the OPs existing system without needlessly throwing out the baby in the bath water?

Troubleshooting electric brakes is extremely easy and low cost to do, replacing with discs is not easy nor cheap and can introduce a few unwanted side effects like possible incompatibility with the OPs existing brake controller..

Jethroish

Scottsburg, IN

Senior Member

Joined: 05/31/2001

View Profile



Good Sam RV Club Member


Posted: 12/29/21 09:15pm Link  |  Quote  |  Print  |  Notify Moderator

I am very comfortable working on brakes. Completely removed drum to make adjustments. Not grease or oil on shoes.
Never really worked on elec brakes before other than adjusting.

Not worth the $ to me to convert to disc since I can replace 4 assemblies for under $500.

I guess the real question is what is normal lifespan od the magnets?

12th Man Fan

Flower Mound , Texas

Senior Member

Joined: 03/05/2009

View Profile



Good Sam RV Club Member


Posted: 12/29/21 10:01pm Link  |  Quote  |  Print  |  Notify Moderator

They should last more than six years unless they have been abused.

I would check and make sure you are getting the full 12 volts to each magnet.

Good luck.


2014 GMC Duramax 4X4 DRW Crew

2015 DRV Tradition

wa8yxm

Davison Michigan (East of Flint)

Senior Member

Joined: 07/04/2006

View Profile


Offline
Posted: 12/30/21 04:56am Link  |  Quote  |  Print  |  Notify Moderator

Though it is possible for a turn. or several turns, to short out the only thing that would WEaKEN the magnets is a bad electrical connection.

Measure the resistance brake lead to ground. Look up the magnets
If the resistance is too high. Bad connection
Too low, Shorted coils.
Note plus or minus 10-20 percent is "normal variation"


Home was where I park it. but alas the.
2005 Damon Intruder 377 Alas declared a total loss
after a semi "nicked" it. Still have the radios
Kenwood TS-2000, ICOM ID-5100, ID-51A+2, ID-880 REF030C most times


Mike134

Elgin, IL

Senior Member

Joined: 11/20/2019

View Profile


Offline
Posted: 12/30/21 06:42am Link  |  Quote  |  Print  |  Notify Moderator

Jethroish wrote:

Could not find anything on this here.
I have a horse trailer with dual 7000# axles. I suspect the brake magnets have weakened. Visually they appear good, but with the brake controller set at the highest setting, only one wheel will lock up on the gravel driveway. Trailer is about 8000# empty. I have adjusted the brake shoes out and they lock up with the trailer off ground.
I know things wear out and eventually need replacing.

Anyone here ever have a similar experience? Did you change out the brakes with a full assembly that included new magnet?

The brakes on the trailer are original (2015 model). Rough guess is the trailer has been towed approximately 60,000 miles in 6 years.


Yes, the magnets are a wear item, the ones on my trailer have 4 holes in them that function as wear indicators, less metal to magnetize equals less gripping power on the drum face to pull in the shoes.

I change out the entire assembly only thing not replaced if you piece meal it is the backing plates.


2019 F150 4X4 1903 payload
2018 Adventurer 21RBS 7700 GVWR.

theoldwizard1

SE MI

Senior Member

Joined: 09/07/2010

View Profile


Offline
Posted: 12/30/21 07:28am Link  |  Quote  |  Print  |  Notify Moderator

wa8yxm wrote:

Though it is possible for a turn. or several turns, to short out the only thing that would WEAKEN the magnets is a bad electrical connection.

Measure the resistance brake lead to ground. Look up the magnets
If the resistance is too high. Bad connection
Too low, Shorted coils.
Note plus or minus 10-20 percent is "normal variation"

Check for bad connection FIRST !

They may have come from the factory with just bared wire, twisted together. If the copper is not shiny, cut it back to where it is shiny. Twisted is acceptable BUT then you MUST use marine/dual wall heat shrink !

Reply to Topic  |  Subscribe  |  Print Topic  |  Post New Topic  | 
Page of 2  
Next

Open Roads Forum  >  Tech Issues

 > Replacing Elec brakes
Search:   Advanced Search

Search only in Tech Issues


New posts No new posts
Closed, new posts Closed, no new posts
Moved, new posts Moved, no new posts

Adjust text size:




© 2022 CWI, Inc. © 2022 Good Sam Enterprises, LLC. All Rights Reserved.