Weak trailer brakes. Sure could use some ideas here!

[CliffordK]

If I could purchase shoes separately, I would have replaced them. Unfortunately, the shoes are only available with the backing plates and they cost $150 per axle. Times 3 axles.

The internet is your friend for finding things like parts that one store says you can't get. However, if you have 4" or 5" shoes, they'll be expensive. Perhaps the store made a calculation, and the whole kit was only $20 more than the bare shoes. Nonetheless, you should be able to find shoes.

There's no practical way to clean grease off of brake shoes or pads. Definitely not with with rags anyway.

Once oily or greasy they're junk. Drums and rotors are easily degreased with brake cleaner, though.

Either way, not relying on Bearing Buddys for getting grease to the bearings is a good idea.

I assume the OP has jacked up the trailer and isolated each axle during testing.

I'm leaning toward grease contamination being a suspect. I might remove the shoes and try to clean them off of the trailer. Some notes suggest soaking in alcohol. Others suggest warming up the shoes in an oven before cleaning.

Shoes, drums, and magnets all need to be cleaned.

Or perhaps purchase an axle worth of new shoes to test.

 

[gstrom99]

I assume the OP has jacked up the trailer and isolated each axle during testing.

I don't remember reading that. I assumed as much also, but... ?

 

[stuckmotor]

There's no practical way to clean grease off of brake shoes or pads. Definitely not with with rags anyway.

Once oily or greasy they're junk. Drums and rotors are easily degreased with brake cleaner, though.

Either way, not relying on Bearing Buddys for getting grease to the bearings is a good idea.

I don't know about modern brake liners, but, on my first brake job on a car around 1974, I didn't replace or rebuild the wheel cylinders and brake fluid leaked out and saturated the liners causing slipping and, "I think" grabbing. My attempts at cleaning them didn't work. After putting in new cylinders and shoes the problems went away.

 

[Dwellonroof]

I had a landscape trailer with a wood floor that always had funky brakes and couldn't figure out the problem until time to replace the treated floor and found a bare wire between the wood and frame.

 

[CliffordK]

I don't know about modern brake liners, but, on my first brake job on a car around 1974, I didn't replace or rebuild the wheel cylinders and brake fluid leaked out and saturated the liners causing slipping and, "I think" grabbing. My attempts at cleaning them didn't work. After putting in new cylinders and shoes the problems went away.

While some trailers (U-Haul) use hydraulic brakes, most use pure electric brakes which this one appears to have.

A smooth track on the side of the brake drum. When the electromagnet is activated, this magnet grabs that track, and the wheel spinning pulls the magnet forward activating the brakes. I suppose somewhat similar to pulling the cable on an emergency brake.

The only normal fluid inside the drum would be the grease that the OP said had leaked around the bearing seals.

Anything could go wrong with a rebuild. One person earlier suggested the brakes are directional. I think the mobile home axle brakes are bidirectional, but most other trailer brakes are directional, and should have been marked right vs left.

 

[Too many Kubotas]

As promised, a tie down job I'm not proud of. Didn't trust just the few chains I had. Not that the lasso straps on the tires would do much good, but still.

 

[CliffordK]

As promised, a tie down job I'm not proud of. Didn't trust just the few chains I had. Not that the lasso straps on the tires would do much good, but still.

Unimog?

Are you using it as a street sweeper?

Or a very different project build?

 

[Too many Kubotas]

Unimog?

Are you using it as a street sweeper?

Or a very different project build?

Yep, a Unimog. It was a tunnel washer. Bought it because it was dirt cheap for an MB4/94 equipped with all the good stuff - front and rear PTOs and hydraulics, working gears (2,000:1) etc.

At first I figured I'd put a hydraulic flail mover on it and cut the grass along the ditches, but with the whole rear apparatus being controlled by switches instead of levers that really wasn't feasible. Aside from the fact that it would'be been a two man operation no matter what.

Then I thought it would be ideal for cleaning the panels at some solar panel place. And it might well have been, but we (thankfully) don't have any of those anywhere near here.

So I removed all the add-ons and sold it for twice what I'd paid. Anybody need a PTO driven articulated broom? It's much like a backhoe except for a lateral break-away feature.

 

[RandyT]

All of the trailers I've seen run two wires from the front of the trailer to the brakes without grounding through the chassis. Lights are often grounded to the frame. On my little red Haulin trailer, I welded the light brackets to the trailer frame to improve the ground.

As far as the brakes, usually 2 wires from the front to the axles, then branching out to all the individual brakes. Effectively in parallel.

The trailer that I own came from the factory with one wire from the front of the trailer to the brakes and grounded to the frame with a self drilling bolt.

 

[jaxs]

3 things I would check
1) all trailer grounds plus truck to trailer ground
2) how the trailer was rewired, connection points all good? Series or Parallel paths?
3) current output on brake controller

<SNIP>

Also D&D above makes an excellent point about serial vs parallel connections for your axles. If you're wired in series you're only getting meaningful output to your first axle

Ya'll have me worried with warnings of series wired so I need to know how someone could make that mistake. I realize there are multiple ways of bringing + and - to each mag but in simple terms the + wire would go from 7 way to + wire on first mag,the - wire on first mag would run to + wire on secound mag,- wire on secound mag would run to + wire on third mag ect ,ect until - wire on last mag runs to - wire on 7 way. Is that how you are saying someone would wire brakes in series or is there other less obvious ways it might be wired in series? I ask because if it looks right to the one who did it,it might also look right to me. I suspect the fist voltage test would send up a flag but I'm asking for the guy doing a visual inspection for broke,disconnected or missing wires.