Brake worse after shoe replace

[Vallka]

Replace the shoes on my electric brakes, magnets look fine, drums are good but now they are pretty weak compaired to before. On my brake controller before I was running it at a three bars (LED's) now I'm up to 7 with less braking power.

 

[MTboatguy]

Sounds like they need to be adjusted out and even if the magnets look okay, it is always good policy to replace them when doing the brakes. How are the flat surfaces on the brake drums where the magnet hits? Normally when I do electric brakes, I just plan on replacing shoes, magnets and drums and purchase a couple of complete kits. I am sure others will have other ideas.

 

[bruceb58]

One of your magnets may have failed. Check the amps when connecting to 12V. Should be around 4A per wheel. For example, if you have one axle with brakes, should be 8A or so

There are a few on here that are very pro electric brakes. I am not one of them.

 

[bruceb58]

Out of curiosity, were your previous shoes worn out and that is why you replaced?

Did you adjust shoes so they were slightly dragging after you installed them?

 

[gm280]

Unless you have the shoes arc ground to the diameter of the drum, it will take some time for them to grind into the drums. You basically only have the outer edges making perfect contact until they wear together. I remember years ago our car shops used an arcing grinder. After cutting the drums they set the arc grinder to the same diameter to give a perfect fit with each other. So it may take some time for them to grind in. That is another good reason for disk brakes! JMHO

 

[NHGuy]

Pick up the wheels, spin them while tightening the star wheel adjusters. Adjust them til there is very slight contact.
You want enough friction to stop the wheel after around 1 revolution or maybe a little less.
If it still has poor stopping check all your electrical connections, brass brush or emery cloth them til they are shiny. All of them.

 

[batman99]

I'm not a fan of factory thin 12 gauge wiring in a linear design. When I installed full electric brakes on my boat trailer (utility trailers and RV trailers), I replaced its factory wiring with much better STAR design - using thicker 12 gauge wiring.

re:

Default Factory: http://i178.photobucket.com/albums/w251/Spike99-Pictures/Trailer wiring/Brakewiring-Linear.jpg
Much better STAR design: http://i178.photobucket.com/albums/w251/Spike99-Pictures/Trailer wiring/Brakewiring-Star.jpg

Note: STAR design brake wiring can be installed on single axle trailers as well.

To create better full electric brakes on your boat trailer, recommend upgrade to STAR design as well. Comparing before and after results are amazing.

 

[bruceb58]

Note: STAR design brake wiring can be installed on single axle trailers as well.

You do realize there is basically no difference on a one axle trailer? The only difference is you may have 2 feet of wire going one direction and 8 feet going the other. With 3.75 A/magnet @ 12V that is only a 0.3V difference assuming the magnets are exactly the same and they never are.

The difference between using 10GA and 12GA is around 0.35V in the main leg of the wire. Pretty insignificant and can be compensated at the controller.

The values I am posting are assuming worst case with 12V output from the brake controller which most people never run.

 

[batman99]

START wiring on 1 x axle trailer.
- Use thicker 10 gauge wire instead of "inside axle" tube wiring
- With junction box in the middle, the current flow is more balanced.
- If wire is yanked out at its hub, the other hub keeps working.

Before saying it doesn't work or not worth it, one should try it themselves.

STAR design is much better than factory linear design - using thinner wire.

IMO, STAR wiring with thicker wire should be minimum code on both single and multiple axles.

 

[bruceb58]

Ohms law says the voltage drop is insignificant.

The percentage difference of the voltage drop is less than the possible percentage difference of the resistance of the magnets.

On any system, if the wire is yanked out of its hub the other hubs still work.

 

[bruceb58]

From the Dexter axle site:

 

[batman99]

Like I said bruceb58.

Instead of quoting factory manuals that meet minimum code and minimum safety margins, recommend upgrading to STAR design with thicker gauge wire (with thicker outer protection sheath) and much better outside axle tube method yourself. Then, give it a real world try. If wondering, I even upgrade axles, upgrade leaf spring packs and upgrade tires to their "next size up" on all my trailers (regardless of number of axles) as well. Thus, better than factory build. Much safer and upgrades last much longer as well. Be better than minimum factory build. And, be safer for others on the road. Works for me...

 

[bruceb58]

Instead of quoting factory manuals...

I kind of like factory manuals. I figure the factory that designed the brakes knows what is sufficient!