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Anyone know anything about trailer brakes?

patooyee

patooyee

Well-known member
Joined
Dec 23, 2020
Member Number
3168
Messages
258
Loc
NWFL
I have an equipment trailer that is 2 years old and the brakes have NEVER worked well on it. I've been relentlessly working on them to no avail. I've been using this trouble shooting guide, which I think has some errors, but is a cut and paste of all other trouble shooting articles I can find on the net:


Brief summary of what I have / I've done:
  • Two 7k braking axles w/12x2 electric drum brakes.
  • I have wired a battery directly to the brake wire at the tongue of the trailer and get the same results as with the brake controller in the truck, so neither the controller or the connector is the issue.
  • I initially adjusted the brakes all the way out and got no improvement.
  • Pulled the drums to inspect, the shoes looked like they were maybe about 50% life, but figured I'd replace everything just to be safe.
  • Put all new drums and backing plate brake assemblies on with new shoes, springs, magnets, etc. The new ones are self-adjusting.
  • The factory brake wire was shitty 18-ga speaker wire with crappy splices, so I replaced it all with 12-ga marine-grade wire with proper butt-connectors and marine-grade heat shrink. This did improve measurements slightly from 11.5 amps at the tongue to about 12.6 amps, but still not the 15 that the article above states I should have and brakes still suck.
  • I've cleaned and redone all grounds.
  • Amperage at each magnet is 3.5-3.6 amps.
I'm at a loss now. All hardware is new as well as all the wiring and the amount of braking improvement I've seen as a result is negligible. I don't know how much I should stress over trying to get the readings that the article states I should have because their math doesn't add up. They say I should have a min of 3.2 amps at each magnet for a total of 15 amps at the tongue, but 3.2 * 4 = 12.8, not 15. With a battery connected directly to the brake wire, the magnets should be able to pull as many amps as they want and they are maxing out around 3.1 ea. I don't know how to make a magnet pull more amps.

Any help would be appreciated. On all of my trailers in the past, with the trailer empty and the brake controller turned all the way up, the trailer tires would lock up. On this one they barely even brake at all. From a size / features POV, this is my favorite trailer that I've ever had but from a braking POV, it's the worst. I want the brakes to match the rest of the trailer. Here's a pic of the new deck I recently put on it.
 

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Outahand said:
You mention the new brakes are self adjusting. Did you do an initial manual adjustment?
Click to expand...
No. All the instructions I found online said to just actuate them a bunch of times to let them self-adjust. (Which is how all my self-adjusters in the past have been.) They are working about as good as the old manual adjusted ones after I tightened them all the way up.
 
Are the shoes the same radius as the drums, they may need to wear in. Adjust them!!!
 
I also having similar issue with my current trailer except it’s weird. It’s pathetically weak at first but become stronger as I drive it. I fully turn up my brake controller and manually engage it for the first few miles to get them ‘hot’ and grabby faster then dial it down to match the load.
 
TrailTamer said:
I also having similar issue with my current trailer except it’s weird. It’s pathetically weak at first but become stronger as I drive it. I fully turn up my brake controller and manually engage it for the first few miles to get them ‘hot’ and grabby then dial it down to match the load.
Click to expand...
I think they get some surface rust on them after periods of inactivity, I noticed that about all my trailers in the past. I have driven while holding the trailer brakes though and there is no improvement.
 
patooyee said:
I think they get some surface rust on them after periods of inactivity, I noticed that about all my trailers in the past. I have driven while holding the trailer brakes though and there is no improvement.
Click to expand...
I thought so too but mine does this the next morning.
 
Is the brake controller working? Is the brake wire hooked up to the right pin in plug? Do you get power to the brake measured at the brakes when you step on pedal? Is the ground from the trailer to the truck good?

Did you put the backing plates on the correct sides?
 
Gbkeith said:
Are you grounding through the frame or do you have ground wires? That’s my go-to solution for trailer electrical problems, especially if anything is inconsistent or just doesn’t make sense.
Click to expand...
Wires. I've removed all the grounds, grinded them clean, and re-installed with new screws.

ThePanzerFuhrer said:
Is the brake controller working? Is the brake wire hooked up to the right pin in plug? Do you get power to the brake measured at the brakes when you step on pedal? Is the ground from the trailer to the truck good?

Did you put the backing plates on the correct sides?
Click to expand...
I eliminated the brake controller and any grounding issues between truck / trailer from the equation by simply wiring a battery straight to the brakes. The results are the same with or without the controller. And yes, someone already asked about brakes on the correct sides, and I am 100% certain that they are.

Steve300xcw said:
Is the trailer plug, plugged into the truck?
Click to expand...
I eliminated the brake controller and any grounding issues between truck / trailer from the equation by simply wiring a battery straight to the brakes. The results are the same wired directly to a battery or plugged into the truck with the controller running them though.
 
patooyee said:
Wires. I've removed all the grounds, grinded them clean, and re-installed with new screws.


I eliminated the brake controller and any grounding issues between truck / trailer from the equation by simply wiring a battery straight to the brakes. The results are the same with or without the controller. And yes, someone already asked about brakes on the correct sides, and I am 100% certain that they are.


I eliminated the brake controller and any grounding issues between truck / trailer from the equation by simply wiring a battery straight to the brakes. The results are the same wired directly to a battery or plugged into the truck with the controller running them though.
Click to expand...
Run a ground wire from the brakes directly to the ground wire in the plug. Not to the frame.
 
Gbkeith said:
Run a ground wire from the brakes directly to the ground wire in the plug. Not to the frame.
Click to expand...
I have. I have run a power and ground directly from a battery to the brakes, nothing between. Same results as with the controller controlling them.
 
patooyee said:
I have. I have run a power and ground directly from a battery to the brakes, nothing between. Same results as with the controller controlling them.
Click to expand...
When you’re sitting there in the driveway applying power you get the same results either way?
 
take a pic with the drums off. so we can see what you're doing wrong!
 
Gbkeith said:
When you’re sitting there in the driveway applying power you get the same results either way?
Click to expand...
Correct. They work / don't work as well when hooked directly to a battery as they do when hooked to my truck with the brake controller at max.
 
V30crewcab said:
take a pic with the drums off. so we can see what you're doing wrong!
Click to expand...
I store the trailer at another property. I'll have to do that next time I have it home. I got tired of messing with it, needed a break, and had other things I needed the driveway for today.

The brakes came assembled though. All I did was bolted them to the axles and hooked up the wires.
 
Gbkeith said:
But when you’re driving they don’t work?
Click to expand...
They work like crap both in my driveway and when driving, hooked to a battery, or hooked to my truck's brake controller. They aren't completely inop, just extremely weak. On other trailers I've owned in the past, with the trailer empty, if I apply max brake power manually, the trailer tires will lock up and smoke. On this one, under the same conditions, you can barely even feel it slowing the truck down.
 
patooyee said:
They work like crap both in my driveway and when driving, hooked to a battery, or hooked to my truck's brake controller. They aren't completely inop, just extremely weak. On other trailers I've owned in the past, with the trailer empty, if I apply max brake power manually, the trailer tires will lock up and smoke. On this one, under the same conditions, you can barely even feel it slowing the truck down.
Click to expand...
I’m starting to wonder if the backing plate flange is not the correct distance to the hub. The shoes are fully seated in the drums? Its like the magnet is too far away to grab the drum and activate the brakes. We need some pictures of the brake assembly and drum.

Take a drum off and give it the full 12v and see how strong the magnet is. The magnet should be really powerful. If it seems weak then your problem is in wires. If it’s strong the brakes are not adjusted tight enough, or the magnet is too far away from the drum to grab and activate the shoes.
 
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Gbkeith said:
If it were my trailer, they’d probably be on the wrong side.
Click to expand...

The stickers are still on the backing plates. If they are on the wrong sides it is because the factory labeled all four brakes wrong. I am going to the property where I keep the trailer tomorrow afternoon to do some work. I will bring the trailer home with me then pull the drums off of one side again and post some pics. But I am 110% certain that the ones labeled LEFT are on the left side and vice-versa because yesterday, as I was running the new brake circuit under the trailer on the creeper, I specifically looked to make sure I got them on the correct sides.
 

My recollection is hazy because I was not specifically paying attention for this, but if the pic in that link is correct, then I think they may have actually come labelled wrong, because I seem to recall the magnet arms pointing backwards, not forwards. I also recall thinking at the time that I must have been doing it right because they faced the same direction as the ones that I took off. (I only did one side at a time confirming that the arms pointed the same direction as the old ones specifically so that I wouldn't screw it up.)

So if they are on the wrong sides, not only were all four labelled wrong, but the original brakes also came on the wrong sides.

That being said, the brakes suck just as bad backing as they do going forwards, so not much hope for this idea.
 
Manually adjust them. Leave them on the tight side.
 
If not bassackwards...

What size wire on power/ground?

Hooking straight to battery should have been a "OH fuck big spark moment" was it?
 
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