Brake Job-Electric Trailer Brakes

[Hook'em_Horns!]

I just did a full replacement on a triple axle…took some pics and thought I’d share. For some, this will seem like some simple stuff. For others that have wondered what was going on back there, well…here we go!

Tools Needed:

Brake Cleaner
Hi-Temp Wheel Bearing Grease (Red)
Box End Wrench & Socket/Wrench (appropriate size)
Large Channel-Lock Pliers
Large Flat-Head Screwdriver
Rubber Mallet
Brake Wrench
Wire Cutters
Stripping/Crimping Tool
Crimp Connectors w/Heat Shrink
1-pc 15” x 18” plywood (or suitable material) to be used for removed parts.
Roll of Paper Towels



Lift and fully suspend the trailer with all wheels clear to spin. Use the Mallet and Large Screwdriver to remove the Center Dust Cap, revealing the spindle and nut with keeper. Some will have a cotter pin; others have a snap-on keeper to remove. Use the Large Channel-Locks to remove the spindle nut, although at this point it will probably only be hand-tight.



Have your plywood on the ground next to you along with the Large Screwdriver. Grab the tire/wheel and rock left and right pulling toward you to loosen the washer and outer bearing. Now, place the tip of the Large Screwdriver on the end of the spindle and pull the wheel toward you until the washer and bearing just slide off the spindle and onto the screwdriver shaft.



Slide those off onto the plywood that you laid beside you (with the cap, keeper and nut), keeping them free of dirt and debris and you from the grease.





Now, pull the complete tire/wheel/brake drum assembly off and roll to the side and out of your way. Here, we now have the complete (worn out) brake workings visible. Grab some paper towels and remove all of the residual grease from the spindle, as you’ll be working all around this and you don’t want to have grease on you from head to toe.



Spray brake cleaner on the five nuts/bolts in the center to clean the threads, and then remove. At this point, you’ll need a block for a working surface to suspend the brake hub assembly as the wires are not long enough for it to reach the ground, I use a standard 8” x 16” CMU block. Slide the assembly off the spindle, place on the block, snip the two wires, and toss it in the trash.



We’ve purchased the complete backing plate/brake assemblies for all wheels, right-hand and left-hand units. About $50/ea, complete with new magnet, shoes, and hardware...best way to go.



Starting on the driver’s side of the trailer, we’ll complete this side before moving to the other, typically the wires are run down this side from the front, and connecting to the axles. Each axle has the brake wires running through it with a grommet holding the pigtails at each end. So, at each axle on the left side you’ll have a three-way connection and the other side just one. Many mfrs will use the cheap and crappy snap/click connectors, the better ones don’t. Snip those babies out, we’re going to use crimp connectors with Heat-Shrink for a positive and trouble free connection. Don’t skimp when it comes to your brakes, do it right. Here, we have prepped our connection, ready for the new brake assembly.



Picture limit, Continued...Part 2

[Hook'em_Horns!]

Lay the new hub on the block (or hang on the spindle if the wires are too short) and attach/crimp the wires,





Melt the Heat-Shrink, slide the new hub on the spindle, and bolt it on, being careful not to pinch the wires on the backside.



Complete the replacements for all axles on this side (we’re doing triples), then Move to the other side and complete those.

Now, let’s tackle the Drum and inner bearings. Remove/pull out the backing ring/seal for the inner bearing, and remove the bearing using your screwdriver again. New seals were purchased (they're cheap) anticipating trashing/bending when removed.

Remove/wipe all of the old grease from the inner hub. Spray down the inner drum with brake cleaner to loosen things up, wipe, and clean.





Having fully cleaned (and inspected for damage) all of the inner and outer bearings, let’s open up that tub of grease and get messy. Grab that inner bearing and push it down in the grease, flip it and bury it again. Pull it out and drop it in the drum, grease and all…you can’t get too much grease here.

Repeat for all hubs on both sides, and then clean yourself up. Using the Rubber Mallet, tap in the new inner bearing seals and wipe up any extra grease that may of oozed out.



Roll the wheels over, pick ‘em up and slide ‘em back on the new brake hubs all the way around.



It’s Time to get messy again! Let’s grease those outer bearings and press ‘em back in all the way around, then clean yourself up again. Install the Washer, tighten up the nut, and replace the keeper/cotter pin. If you recall when we started, those nuts were loose. The bearings were low on grease and the wheel probably had a toe out under load. The bearings are full of grease now, the nut is tight, and the wheels are standing tall with no toe out as before. Grab the Mallet and tap the dust covers back on.

Remove the oval plug on the bottom/backside and using the Brake Wrench to adjust, let’s snug things up, and then back off a few clicks. Plug in the trailer and apply the brake controller. Walk around to each wheel and listen for the hum/whine of the magnet, just to be sure there’s no problems with any wire connections. Lower it down, hook it up and take it for a test drive to see how they feel. You may need to adjust them some more to get ‘em just right.

Happy Trails!