Trailer brakes weak, a few questions:

[BobsYourUncle]

32 foot TT, about 7000 pounds plus our gear and stuff:

I've noticed the brakes are underperforming substantially. Got the gain on the Prodigy turned all the way up, when I grab the lever and throw max voltage at the brakes, all it does is slow the thing down a little. I'd say maybe 20 percent efficiency at best.

Not good enough, time to open it up.

I've been wrenching my own vehicles since I was a teenager, I rebuild engines, trannies and every other aspect of cars and pickups, therefore I know what I'm doing with mechanical things.

I've been doing brake jobs all my driving life.

However, I have never had trailer brakes apart.

I'm wondering, do most trailers have a similar adjustment technique as the old drum brakes on the old 60s and 70s cars? Where you pull off the little rubber cap on the backing plate and get in there with a brake tool or bent screwdriver?

Weak brakes, could they just be suffering from bad need of adjusting?

Are they self adjusting like the old cars or do we have to get after them once in a while?

Just thought of this now, but suppose I should get under there, probe the wires and make sure I have voltage at the hubs....

Should be able to lock the wheels up with full on braking. Not so here...

Tips and tricks for getting my brakes in order? Best method to check each wheel?

Guess I should pull the drums and have a peek anyways.

Long trip coming up soon, gotta take care of this before departure.
TT is 12 years old, maybe it needs shoes.

[peirek]

Lynnmor wrote:
Forget the grease gun and inspect the bearings, then hand pack with real wheel bearing grease. Never use the grease fitting. Install new grease seals. Scrap the tires and get new ones made in USA. Simply do things right.

Agree on not using the grease fittings. Unless of course you want to grease your brake pads via seal blow by - as personally experienced 😞

As for the weird tire wear. I also experienced that on my original set of tires, China bombs. I was concerned my alignment was bad. Long story short, running Maxxis (upgraded to load range D) for 9+ years now (not same set) and wear is even. Not trying to start a tire debate, just stating my experience.

Brakes, bearings, and tires should never be neglected.

[Lynnmor]

Forget the grease gun and inspect the bearings, then hand pack with real wheel bearing grease. Never use the grease fitting. Install new grease seals. Scrap the tires and get new ones made in USA. Simply do things right.

[BobsYourUncle]

Update:

I pulled one hub apart today to have a look in there.

They are Dexter and I recorded the ID tag info for part numbers etc. Forgot to measure the ID of the drum, but I measured the OS at 12 inches.

Shoes are ok, some wear but still lots of life left on them.
They are not self adjusting.

I checked the rub mark of the magnet travel on the backing plate. It was moving the max amount it could travel. Looks like it's been years since they were adjusted. Ive never adjusted them. The wheel spins freely with no drag.

Everything was in good shape in there. Some wear on the magnet and drum, but not excessive.

I checked to make sure each wheel was operating, and adjusted the shoes quite a bit until I had the slight drag needed for proper operation.

Didn't take the hubs off the other 3, figured they'd all be about the same.

And as an added bonus, the hubs are equipped with the easy lube grease nipple thingy. Bonus! I own 2 grease guns, went hunting for them tonight. You think I could find them?..... Nope, no idea where they are. Oh well, they didn't have the right grease anyways, guess I'll buy another one and get some good high temp grease.

Hooked it up and took it for a boot, brakes are now satisfactory. Had to turn the gain way down on my Prodigy to avoid dragging the tires on the pavement.

But while I was under there I noticed the tires have really strange wear patterns on the tread.... sort of a cupping wear pattern. One tire has the tread chewed right off on the inside and is badly cracked. Hmmmm.... Gotta buy a new one. Odd date codes too. All letters. Hmmmm again. Goodyear Marathons for 3, one China bomb mismatch. Spare is brand new, never used.

Thanks for the help and input everyone. 🙂

[Groover]

wopachop wrote:
So for a 3 axle trailer that would be 18amps. Thats impossible to get from the 7 pin controller right?

They can handle 18amps. Of course, the higher the amps the more important it is that all of the connections are good.

[wopachop]

So for a 3 axle trailer that would be 18amps. Thats impossible to get from the 7 pin controller right?

[Groover]

ajriding wrote:
3 amps or 3 volts?


Easier to lock up one wheel on a tandem than on a single axle trailer. Easier still on gravel.

Daisy chain leaf springs take load off of the front axle when braking. I have even seen a lightly loaded trailer lift the front axle completely off of the ground with the brakes engaged too firmly. This is normal and nothing that you can do about it.

The problem is that you have to choose between skidding the front axle in hard stops and not having enough braking in panic stops.

[Groover]

BobsYourUncle wrote:

ajriding wrote:

How long did / have you driven your trailer with unsatisfactory brakes?

Last summer going through the Canadian Rockies, I noticed they were not as efficient as they should be. They worked, but could have been better.

Took it out last weekend for the first time this year to bring it home to dewinterize. Noticed it was worse, much worse...

Taking care of it before an upcoming trip

If I let my trailer sit very long at all I have to do several stops using just the trailer brakes to get them working effectively again. Even then they don't ramp up well. Great for normal stops but not for rapid stops. And I keep the trailer out of the weather so that shouldn't be a factor.

If you do major work on the brakes keep in mind that you may need to burnish in the new parts to get effective braking. This can take a while.

[Groover]

wopachop wrote:
Wait a second. This came up before with the emergency brake system.

If you remove your batteries from a trailer will the brakes work properly?

For normal stops, yes. The power comes from the tow vehicle. Batteries on the trailer supply power for breakaway situations. Important if needed but hopefully you will never need that. And it probably is a different battery from the one that runs the camper. You should pull the breakaway cable now and then to be sure that the emergency breaking works.

[BobsYourUncle]

DFord,
Thanks, that's helpful.

[stevemorris]

ajriding wrote:
3 amps or 3 volts? previous poster said this… Should not matter unless you suspect issue with wiring or controller. Brakes work off a 6 volt system, not 12. The max output for the controller is 6 volts. That should be 6 volts per brake, not 3 (amps get divided, but not volts here). Usually anything over 2 will operate the brake magnet then from there to 6 will increase the magnetism and increase the braking power.

I recently let trailer sit for a couple of months then the brakes were very, very weak at first. I had the controller set to max and still was not great breaking. 2 hrs drive and I could gradually lower the controller setting and the drive back I was back to normal with the controller set very low to get the power out of the brakes I wanted.
Maybe the drums rusted over and it took that long to wear it off and evacuate the debris from the inside of the drum? I don't know.

The trailer should at least be able to stop its own weight.

How long did / have you driven your trailer with unsatisfactory brakes?

Brake pads should be able to sit for 12 years and still work, though the steel parts might see some rust and need exercising or brake grease to move easily.

Easier to lock up one wheel on a tandem than on a single axle trailer. Easier still on gravel.
They need to be adjusted, as stated above, as the brake pads wear out and to keep all wheels performing at the same level. Typical drum brake adjustment rules apply. See any of the many instructional videos or post on topic.

6 volts? seriously? not on my trailer they don't nor any other ive had

brake magnets are in parallel and all see 12V at full power and 3 amps each(depending on size) for a total of 12 amps on a tandem trailer

the biggest issue with the electrical system for these brakes is voltage drop due to the high current draw. this is usually because of insufficient wire size and or bad connections.

all of the wire used has to be big enough, all the way from the tow vehicle battery to the brake controller, to the 7 pin connector and around the trailer. that's a lot of wire!

[DFord]

Dexter Axle makes most of them. Look all around the Eastern Marine website. They have all sorts of educational material besides the parts.

Also peruse the Dexter Axle website: https://www.dexteraxle.com/ They have lots of support information available.

Lots of links to instruction sheets on this page:
https://www.dexteraxle.com/products/brakes-brake-accessories

Etrailer's website is also very helpful:
https://www.etrailer.com/question-143453.html

[BobsYourUncle]

On another note, how do I ID the brakes for replacement parts aside from a visual comparison after pulling it apart? In case I need to buy shoes, drums, magnets or whatever.

Gotta be something stamped, tagged or ? To ID them

[wopachop]

Wait a second. This came up before with the emergency brake system.

If you remove your batteries from a trailer will the brakes work properly?

[DFord]

3 AMPS PER MAGNET should be able to lock the drum. That would be the maximum current draw per brake. Usually much less than that but if you're magnets are drawing anywhere near that much power and the brakes aren't working correctly, it's not a wiring issue. It would be time to pull a drum and see what's going on inside.