Weak Brakes on AIM 15BH

[gDanColeman]

Question: I just bought a Grand Design AIM 15BH. The brakes seem very weak. When rolling at 25mph, if I do a pinch test with my brake controller set to 10, the trailer barely slows at all. I have had 3 RV's before this new one that I've had now for only 2 months. All of the previous travel trailers could actually lock up the wheels and skid the tires if the brake controller was set too high. The new Grand Design, however, barely slows at all and I have the brake controller to maximum. Any advice? Anyone?

[Country Campers]

Sounds like the brakes are not adjusted correctly. You can find videos on how to adjust trailer drum brakes or if you have someone who can show or help you go that route. This is common to see that brakes are not adjusted properly from the factory, actually the axle manufacture should do this.

Brian

[TucsonJim]

If you have an old style magnetic compass, you can do a quick test to see if the magnets are energizing.

1. Hook up the 7-way connector to the tow vehicle, and start the engine.
2. Hold the magnetic compass near the bottom of the wheel.
3. Have someone press on the brake pedal or squeeze the controller. If you don't have an assistant, you can pull the break away lanyard.
4. Watch the needle on the compass when the brakes are applied.
5. If the needle moves, the brakes are getting electrical current to the magnets, and further adjustment of the brakes is needed. If the needle doesn't move, the brake's electrical system needs trouble-shooting.
6. Repeat for each wheel.

It's not uncommon for one or more brake magnets to not work properly. The compass test will let you know if this is the case.

Jim

[Jlawles2]

If you do pull the break away switch be advised that it's not intended to be left energized for long periods of time. I'd try to limit myself to 5 minutes or less with a 20 min break between test.

I'm wondering if you could do the same test with a clamp on amp meter by measuring the amps flowing through one of the wires.

I'll have to try this when the weather gets better.

[Mitchell & Kitty]

This summer we visited my daughter in Jackson, WY. Teton Pass is one of the few ways to get into town. I always take it easy coming down it for fear of smoking the brakes. After getting back from that trip I noticed that the trailer wasn't braking like it used to. Very mushy. I figured the pass must have been the culprit. I was under the trailer for setup and noticed a broken wire going into the axle. Must have hit a rock or something. I rehooked the wire up and low and behold the brakes weren't mushy anymore. Have you looked at your brake wires?

[Yoda]

Question: I just bought a Grand Design AIM 15BH. The brakes seem very weak. When rolling at 25mph, if I do a pinch test with my brake controller set to 10, the trailer barely slows at all. I have had 3 RV's before this new one that I've had now for only 2 months. All of the previous travel trailers could actually lock up the wheels and skid the tires if the brake controller was set too high. The new Grand Design, however, barely slows at all and I have the brake controller to maximum. Any advice? Anyone?

First welcome to the site. Do you know if you have self adjusting brakes? There is a tag on the back of the axles, take a picture of it and post. If the axle is Dexter you can request a build sheet for your specific axle. That sheet will give you all the parts and springs used to build you axle. I believe Lippert will do the same. It may be you just need to burnish the brakes, There are several threads here on it and both Dexter and Lipperrt have specific instructions. Basically it is a series of repeated stops that work to seat the pads, etc.

Now you also do not list you tow vehicle. Is you controller built in. As an example I have the factory Ford controller and there are actually 3 settings to check. First is trailer and brake type. Then initial effort and finally gain. Perhaps pull out your owners manual and review the settings your using. It can make a huge difference. The reason I say this is I swapped out axles and had to start the break in procedure form scratch. After reviewing my settings and making a few changes I saw a lot of improvement.

Hope this helps
Keith

[TucsonJim]

I'm wondering if you could do the same test with a clamp on amp meter by measuring the amps flowing through one of the wires.

That is a great way to test the brakes. A typical 12" trailer brake magnet will draw between 3.2 and 4.0 amperes. This will confirm that current is flowing through the wire. The compass test will confirm a magnetic field has developed. Another test is to jack up each wheel, spin the tire and apply the brakes to make sure it's stopping wheel rotation.

Jim

[Lonestar]

The brakes seem very weak.

My trailer was the same way, and I had never had this issue on previous trailers.

As mentioned above, it seems that now there is a real need to burnish the brakes, or in other words get the brake pads and drums to seat properly.

I was not aware of the burnishing procedure, but after about 1K miles of braking mine started to work fine. I did adjust the brakes again at that point.

[gDanColeman]

Thanks for all the advice friends. I guess we can conclude that my brake magnets are definitely getting power on the basis that I am getting some braking. The idea of burnishing in the new brake pads and drums really seems like a viable solution. I'll try that and if I do not see improvement, then I certainly must have the brakes looked at -- and adjusted. Again, thanks to all of you who responded. Blessings!

[Country Campers]

Thanks for all the advice friends. I guess we can conclude that my brake magnets are definitely getting power on the basis that I am getting some braking. The idea of burnishing in the new brake pads and drums really seems like a viable solution. I'll try that and if I do not see improvement, then I certainly must have the brakes looked at -- and adjusted. Again, thanks to all of you who responded. Blessings!

I would make sure that the brakes are adjusted before trying the burnishing route. I do not think that you will get any results by burnishing the brakes if they are not properly adjusted.

Brian

[Cate&Rob]

x2 on the advice from Country Campers Brian.
Without auto adjusters, the brake shoes must be manually adjusted before burnishing will work.

Rob

[Jlawles2]

I'll be the Negative one here.

After you come to a stop (long drawn out trailer brakes only in a safe spot), get out and run (hurry as fast as safely possible) back to the trailer and smell for anything other than burning brake lining. You could be the victim of a blown inner grease seal which has lined the inside the drum with grease leading to ineffective brakes. If the dealer or someone has used the through hub fittings it's possible that they pushed some or all of the seals out of the hubs.