What broke now...the brake!

Sweeney

Administrator
This summer, I had a problem with my brakes, there was a similar post from some one else too. This is my "confession" of the event.

This past summer I went deeper into trailer brake repair than I ever wanted to. Frankly, enough that I have just about sworn off doing brake work on my own rig entirely. Bearings, I'll do every time - but brake replacement -- Well, I want to share what happened. Partly as a heads-up for other owners, but mostly because I owe CampInn and their staff a very public thank-you. Long post. Edited with AI assistance, but all my thoughts. Grab a coffee.

I have a 2021 560 Ultra. The brake situation I'm about to describe almost certainly applies to the entire line, since the brakes are the same across the board. The big difference in my case is that I have the parking brake option. Some of what I experienced was probably made worse by that because of the added complexity — but much of it will apply to everyone.

To understand what went sideways, it helps to know how electric trailer brakes work. The heart of the system is an electromagnet mounted on a small pivoting arm inside each brake drum. When your brake controller sends current, that electromagnet is attracted to the spinning drum. The drag rotates the arm slightly, which pushes the brake shoes outward against the drum. More voltage, more force. It's elegant in a 1950s sort of way. It's also been essentially unchanged since the 1950s, which is going to be a theme here. The industry really needs to start thinking more forward — there are other ways this could be done much better, both in braking effectiveness and simplified maintenance of the wheel and axle system.

It all started with a pothole. Just the kind you can't always avoid on Indiana roads. About 40 miles later at my next stop, I noticed the wheel on the opposite side was hot. The shoes were dragging, or a bearing had failed. I grabbed parts and did an ad-hoc repair right there in the campground — which sadly didn't help. The brakes overheated again on my drive home.

Here's the odd part: the brake that first acted up wasn't even on the side that hit the pothole. That detail matters because it sent me down a rabbit hole. Did the pothole cause this? I don't know — and neither did the tech who ultimately fixed it. It was just odd.

In theory, the fix is simple: replace the backing plate assembly. Four bolts, two wire connections. Pull the old plate, hang the new one, adjust the shoes, done. That's not how it went.

What "Simple" Actually Looked Like

Brakes should be 4 bolts, and 2 wires. The fact I had problems on both sides, tells me it wasn't me -- it was something more systemtic.

I went through two complete sets of backing plate assemblies and drums. Once overheated, the brakes were suspect and the drums scored. Drums and brakes are replaced in pairs, and I'm a stickler, so I was buying a complete set for both sides. Hundreds of dollars in parts. None of it fixed the problem — which also tells you that however the manufacturer designed these components is a bad design, not just a "bad part," which happens periodically.

Here's what I learned the hard way about why this job is harder than it should be.

The parking brake option. CampInn modifies the standard brake components to support the parking brake cable. The arms the cables attach to are different from the stock components — they need to be removed from the old assembly and reinstalled on the new one. If you don't know to do it (and in hindsight, I was told), you'll either install the new plate wrong or lose an inherent geometry improvement in the process.

I want to keep my parking brake. I do chock my wheels, but I love the ability to pull a lever at the campsite for additional stability — especially since some of the sites I stay at aren't level. Belt and suspenders makes me sleep better. That said, this experience has me questioning whether I keep this option going forward.

The magnet arm. On the assemblies I received, the arm that holds the electromagnet against the drum was approximately 5 to 10mm too long. It physically couldn't seat correctly without modification. Either the wheel would not go on, or when you turned the wheel, the arm would rub the drum — or worse, get stuck in the holes the wheel studs are pressed into. You have to cut it and chamfer the edges. Not difficult, but it suddenly becomes a repair that requires tools, and is no longer an emergency roadside operation. And you shouldn't have to do any of this. Chasing down the problem on a brand new set of parts cost me real time. That's a manufacturing tolerance issue the brake manufacturer has made — and is not taking ownership of.

The assemblies were gummy. This is the one that cost me the most. The brakes would apply but not retract as they are supposed to, causing the shoes to press just tightly enough against the drum to generate heat. As I drove, that stiction was enough to partially apply the brakes on its own. Partially applied brakes generate heat. Heat damages everything — drums, shoes, magnets. By the time I understood what was happening, I'd cooked a set of brakes I'd just installed.

I contacted the brake manufacturer — a few emails back and forth with their support team. I'll leave the name out, but anyone who's worked on trailer brakes knows exactly who makes the dominant components in this space. The conversation went nowhere. Rather than try to understand whether there was a batch quality problem, the response was essentially that I had done something wrong. That was the end of that.

How CampInn Fixed It

CampInn went out of their way to help, as always.

Their tech rebuilt my brakes by hand — taking each assembly apart, cleaning, and filing parts until they moved freely. We never had an absolute smoking gun for what happened or why the original brakes lasted 10,000 miles without a problem and then suddenly grenaded. Nor why the new parts failed as well. Either way, CampInn fixed the problem by doing what the OEM should have done in the first place.

After the mechanical work, since there was still no smoking gun, we didn't know if it was an electrical or mechanical problem. Was the brake controller contributing — sending a slight voltage that kept the brake dragging? Or was there still something not quite loose enough? So for the first 300 miles or so, I drove with the controller electrically disconnected. Everything was fine. I plugged the controller back in and confirmed the mechanical fix had resolved the issue. After reconnecting, everything has been working fine.

I do now stop every rest stop or two, and any time I get out of the vehicle, I do a quick temperature check — back of the hand near the wheel, a quick tap to make sure it's cool.

I want to be absolutely clear: CampInn did not cause any of this. It's antiquated technology built by a company with a problem they are not willing to address. It all goes back to an industry that needs to be better regulated — or self-regulated. Unfortunately, if regulation comes, the prices of already expensive parts will only get worse, making this thing we love even more expensive.

CampInn went further than any reasonable person would expect to make it right. As we all know, they are extremely dedicated to quality manufacturing. The RV world would be so much better if everyone operated that way.

I've been doing my own trailer work for years. Not long ago I would have told you brakes were an advanced DIY job — doable if you're mechanically inclined and willing to do your homework. I wouldn't say that anymore. As a trained technician, my frustration level hit flying-tool territory. Not because the job is technically beyond a capable person — mostly because the parts ecosystem has gotten unreliable enough that unless you do this every day, it's too easy to miss something. Wheel bearings on my own rig? Sure. Brake adjustment? Yes — every 3,000 miles. But full replacement, knowing what I know now? I might do it. But I would not recommend it unless you do this work every day.

RV and camper components are getting more cheaply made. Support from the manufacturers is getting worse. That's not a CampInn problem — it's an industry problem. And it's getting harder to work around.

The electric trailer brake system itself is, frankly, ancient. The basic design hasn't changed meaningfully in decades. There are better options out there, and I'm going to spend some time this winter looking seriously at what a replacement might look like for Serenity. When I have a real answer I'll post an update. For now, I'm waiting for the seasonal slowdown to give me a few hours to dig into it properly.

I hope this saves you a set of drums — and the hour it took to find that wrench I threw.
 
Ouch. This kind of thing makes me crazy when I think I can do something but parts have changed...

Question @Cary Winch For those of us without handbrake, does the parts now available require filing? I recall you Cary saying you do "something something" in new units as built up, but cant recall if thats on all or just with handbrake.

If so, @Sweeney ot @Cary Winch if possible could you reply here or by email with a diagram showing what little bit where and how much to hand file down...

Plus the latest standard part number...source.

I'd like to carry a pair for spare, just like the advice to carry spare bearings if on the road to DIY or hand the instructions to the kid at the automotive shop delegated the job, to include "don't pack the hub full..."

Most highly appreciated and would be highly valuable.

TIA.

PS: time to dig out that long thread on how-to-doing the bearings. Its that time again.

Agree with @Sweeney
Bearings not that hard, just a little messy.
The right tools help, and are easy to buy and keep in CI toolbox.
 
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Ouch. This kind of thing makes me crazy when I think I can do something but parts have changed...

Question @Cary Winch For those of us without handbrake, does the parts now available require filing? I recall you Cary saying you do "something something" in new units as built up, but cant recall if thats on all or just with handbrake.

If so, @Sweeney ot @Cary Winch if possible could you reply here or by email with a diagram showing what little bit where and how much to hand file down...

Plus the latest standard part number...source.

I'd like to carry a pair for spare, just like the advice to carry spare bearings if on the road to DIY or hand the instructions to the kid at the automotive shop delegated the job, to include "don't pack the hub full..."

Most highly appreciated and would be highly valuable.

TIA.

PS: time to dig out that long thread on how-to-doing the bearings. Its that time again.

Agree with @Sweeney
Bearings not that hard, just a little messy.
The right tools help, and are easy to buy and keep in CI toolbox.

A few important notes before diving in: None of this applies if your trailer doesn't have brakes, and it's only marginally more relevant if you have the parking brake option.

I hesitated to post this — it's a can of worms, and frankly it has nothing to do with CI except that they happen to have someone here who knows brake systems better than anyone I've ever met. The part numbers are essentially irrelevant since there's no other option at this point anyway.

If you hire this job done, this is a problem your trailer guy has to deal with. One of the risks of going the DIY route: once you take this job on, it's yours. In my experience, finding a tech willing to touch it afterward is very difficult. My situation is unique since this is technically part of what I do for a living. It is a bit of a humiliating experience to have to throw in the towel on this one. But, honestly and transparency is something we need more of in the world today. After this experience, I'm no longer willing to take on brake work. I won't accept the liability. Once I gut off that nub, if there's an accident the next person the lawyers will be talking to would be me.

Wheel bearing service is also part of this job since you have to pull the bearings to access the brakes. Those are much easier and are part of this job. But this may help you see why most technicians don't want to touch these things.

Make no mistake — I do believe the average owner benefits from learning their own maintenance. Especailly for emergency roadside problems that can happen. This crosses the line from maintenance and repair into engineering. The component manufacturer has put the technician in a position where they have to modify a part to make it function. That means you own that problem from that point forward. If there's ever an accident, the technician is the first call — and they'd better have a good lawyer.

In my case, the repair required complete disassembly of the backing plates down to component level, essentially finishing work the manufacturer should have done at the factory. It was a heroic effort. What industry time tables show as a 2-hour job took me 4–6 times that before I picked up the bat phone to wisconsin

Next time, I may try switching manufacturers — there are only two, Lippert and Dexter — though I honestly doubt it will make much difference. this is all 1950's technology that both manufacturers are working around. Hopefully I'm a few years away from having to deal with this again. Under normal circumstances, trailer brakes last a long time.

The actual repair:

The first problem is the nub on the backing plate that retains the magnet. If you look at the photo, the magnet is at the 6 o'clock position on the backing plate — you can see the tip of the nub just beyond it. I used a Dremel to remove that small extension. The correct amount to remove is determined by pressing the magnet on as far as it will go, then filing off anything that still protrudes.

There is a small spring that holds the magnet against the drum. It is made from extremely fine wire — almost impossibly light. Handle it carefully.

From the factory, there is a slight extension on the nub that goes beyond the magnet face. The tolerances are simply too tight. That protrusion was rubbing against the drum and catching in the holes where the wheel studs are pressed in. The rest of the repair was figuring out why parts were sticking. Once the brake was applied it was not releasing causing the shoes to 'drag'

Technically, none of this modification should be necessary. There are only two trailer brake manufacturers — Dexter and Lippert. All parts I used were Dexter. The Lippert design may differ, but Lippert wasn't in stock when I ordered.

The difference between a standard brake and a parking brake model is the spreader plate at the 12 o'clock position on the backing plate.
 

Attachments

A few important notes before diving in: None of this applies if your trailer doesn't have brakes, and it's only marginally more relevant if you have the parking brake option.

I hesitated to post this — it's a can of worms, and frankly it has nothing to do with CI except that they happen to have someone here who knows brake systems better than anyone I've ever met. The part numbers are essentially irrelevant since there's no other option at this point anyway.

If you hire this job done, this is a problem your trailer guy has to deal with. One of the risks of going the DIY route: once you take this job on, it's yours. In my experience, finding a tech willing to touch it afterward is very difficult. My situation is unique since this is technically part of what I do for a living. It is a bit of a humiliating experience to have to throw in the towel on this one. But, honestly and transparency is something we need more of in the world today. After this experience, I'm no longer willing to take on brake work. I won't accept the liability. Once I gut off that nub, if there's an accident the next person the lawyers will be talking to would be me.

Wheel bearing service is also part of this job since you have to pull the bearings to access the brakes. Those are much easier and are part of this job. But this may help you see why most technicians don't want to touch these things.

Make no mistake — I do believe the average owner benefits from learning their own maintenance. Especailly for emergency roadside problems that can happen. This crosses the line from maintenance and repair into engineering. The component manufacturer has put the technician in a position where they have to modify a part to make it function. That means you own that problem from that point forward. If there's ever an accident, the technician is the first call — and they'd better have a good lawyer.

In my case, the repair required complete disassembly of the backing plates down to component level, essentially finishing work the manufacturer should have done at the factory. It was a heroic effort. What industry time tables show as a 2-hour job took me 4–6 times that before I picked up the bat phone to wisconsin

Next time, I may try switching manufacturers — there are only two, Lippert and Dexter — though I honestly doubt it will make much difference. this is all 1950's technology that both manufacturers are working around. Hopefully I'm a few years away from having to deal with this again. Under normal circumstances, trailer brakes last a long time.

The actual repair:

The first problem is the nub on the backing plate that retains the magnet. If you look at the photo, the magnet is at the 6 o'clock position on the backing plate — you can see the tip of the nub just beyond it. I used a Dremel to remove that small extension. The correct amount to remove is determined by pressing the magnet on as far as it will go, then filing off anything that still protrudes.

There is a small spring that holds the magnet against the drum. It is made from extremely fine wire — almost impossibly light. Handle it carefully.

From the factory, there is a slight extension on the nub that goes beyond the magnet face. The tolerances are simply too tight. That protrusion was rubbing against the drum and catching in the holes where the wheel studs are pressed in. The rest of the repair was figuring out why parts were sticking. Once the brake was applied it was not releasing causing the shoes to 'drag'

Technically, none of this modification should be necessary. There are only two trailer brake manufacturers — Dexter and Lippert. All parts I used were Dexter. The Lippert design may differ, but Lippert wasn't in stock when I ordered.

The difference between a standard brake and a parking brake model is the spreader plate at the 12 o'clock position on the backing plate.
Thanks @Sweeney
 
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