Electric Trailer Brakes Rebuilding: A Story About How They Work and What Happens When They Don't

This story begins when I offered to haul mySafety House. They could use some work on
friend's Aerostar van for him. He lives at the toptheir web site, but they have great prices.I found
of a very steep gravel hill.We drove the van ona pair of new drums on e bay and I was the only
the trailer, strapped it down tight, set the weightperson who bid so I got both for the price of one.
distributing hitch and I headed down the hill. It wasThen the wait for Danny - my UPS driver - to
all going well until I hit the brakes.Basically therebring them to me. Naturally the drums and
were none. Only the fronts on the Suburban weremagnets arrived on different days so he got to
locking. I pushed the big red button on my homevisit with my dog Smash twice.Upon closer
made trailer brake controller giving them the fullinspection of the trailer brakes, I noticed that I still
13.7 volts but nothing. Well almost nothing. I wasdid not understand how they worked. Something
still going down way faster than I wanted to!Thejust did not look right about the way the cams
trailer brakes should have locked up solid whenworked. It sure looked like they would be
the red button is pushed making everything atstronger in reverse. And this trailer has always
least slide straight - instead of the trailer trying tobeen tough to back up when the brakes are
pass the Suburban. Talk about the cart beforeworking right.A quick look at the Dexter Brakes
the horse!The way the load was pushing aroundweb site confirmed my suspicions. The rear axle
that Suburban, I was really glad I had not tried toon my trailer was installed backwards.I decided
tow with my little Jeep Cherokee.Once that jobthe bearings did not really care if they were
was done I backed the trailer into the shop tospinning backwards, so I elected to simply swap
take my first look at those trailer brakes. I havethe brake assemblies left to right.Having them off
owned this trailer for nearly twenty five yearsmade installing the magnets and routing the not
and I have never seen inside the brake drums onso little green wires somewhat easier. I found that
it. I guess it was about time.My inspection of thesome lubricant made getting them through the
first drum showed me a little about how electricgrommets a lot easier.Dexter Magnets are
trailer brakes work. There is an electromagnetidentified by the wire color. The correct one for
that pulls against the inside of the drum. Themy 3500lb axles is the green wire. Nice they have
friction of the magnet against the drum movesnot changed that in 25 years.The magnets are
one shoe that in turn moves the other shoe withheld in by spring clips that are really hard to get
a cam action.Pretty simple. But I did not seeoff. I used a small screwdriver and a pry bar and
anything wrong. The shoes looked fine, the drumbent them slightly to get them off. The new
was fine except for some scoring where themagnets came with new clips anyway.I loaded the
magnet rubbed. I put power to the magnet and itnew bearings with axle grease and installed the
seemed to pull OK. But, the friction of the magnetnew brake drums. They are not Dexter brand but
against the drum was obviously not enough tothe fit just fine.The wiring is was pretty simple to
work the shoes.I could not figure out how areconnect since there is no polarity on the
magnet could go bad, but that is what it seemed.magnets. Just connect one wire to the brake
Time for some Internet research.I eventuallycontroller power lead and one to ground. Dexter
found a site that said magnet failure wasrecommends running a separate ground wire but I
common on electric trailer brakes. So I wentjust grounded it to the trailer frame like it had
shopping for trailer brake magnets. Most placesbeen done before.Now my trailer has brakes
wanted more for the magnet than I could buyagain.For pictures that go with this article see
the whole backing assembly for. To get one at aStrawbridge is the owner of Straw Solution
local parts store I would have to pay more than IPerformance Improvement Consulting. He enjoys
could buy two backing assemblies for. And newhelping others achieve their full performance
magnets are included in the backing platepotential and knows a thing or two about keeping
assemblies.Just when I was about to give up andthem safe while doing so.
order new assemblies, I stumbled upon Auto