Weak Brakes???

M&M · 07-29-2013, 08:15 PM

Can someone with a 210WBS or similar tell me how strong their brakes are?

I just finished packing the wheel bearings and cleaning and adjusting the brakes. I freed up the frozen adjusters and adjusted the brakes so the trailer wheels will turn about 1 time when spun by hand. All brake parts looked good. The brake shoes, drums, and magnets were wiped off before assembling. I lightly sanded any rust off of the drum surfaces where the shoes make contact. I jacked up each wheel and tested to make sure all the magnets all worked, which they did. I plan to test the voltage and possibly the amperage at the wheels but will need to get a better tester first.

When I got done, I tested the brakes. With the gain set to maximum, I can’t lock the wheels up with the manual control, even on gravel. The trailer brakes alone take a lot of distance to stop the pickup and camper and generally feel pretty weak. If I engage the breakaway switch, there is braking but still no lock up. The camper and pickup are basically not loaded. I also tried setting the shoe adjustment again after testing the brakes, but no improvement.

I had thought I could lock up the wheels last year when I was testing the brakes, but maybe I am remembering wrong. Any ideas would be appreciated.

Also, are the brakes grounded to the frame somewhere? If so, I haven't found it yet.

Eagle · 07-29-2013, 08:56 PM

Did you look closely at the shoes to be sure they were not glazed? If they are they can be roughed up with sandpaper.

Just a thought.

**LJAZ** · 07-30-2013, 08:20 AM

You should be able to get the brakes to lock up. The Dexter axle troubleshooting guide lists these possible condidtions for weak brakes:

GREASE/OIL ON MAGNETS/LININGS -- CLEAN OR REPLACE
CORRODED CONNECTIONS -- CLEAN/CORRECT CAUSE
WORN LININGS OR MAGNETS -- REPLACE
SCORED/GROOVED BRAKE DRUMS -- MACHINE OR REPLACE
IMPROPER SYNCHRONIZATION -- CORRECT
UNDER ADJUSTMENT -- ADJUST BRAKES
GLAZED LININGS -- REBURNISH OR REPLACE
OVERLOADED TRAILER -- CORRECT

One of the magnet leads should ground to the frame somewhere.

webslave · 07-30-2013, 11:32 AM

While a failing brake controller may give the symptoms you describe, the break-away switch should certainly lock up the wheels and most assuredly should be able to lock them on gravel.

Your best bet is to go over the whole system. With the age of your trailer, I'm going to assume that the shoes have never been replaced. So I would start with a replacement. Shoes get contaminated and glazed and with time "compacted" to a hard surface that won't grip the drum. You can try burnishing them (sanding), but, I've always had less than stellar results with that and if the pad material is compacted, it will be a short lived improvement. Even if they aren't the source of your problem, I would replace them, based on age, anyway. I would also shop around when looking for the shoes. Quite often for just a bit more, you can get the shoes, magnets and backing plates; completely replaces the original and is bolt on affair; most are already assembled and 4 bolts and the wire joints is all that is required. That would kill all the other birds at the same time (bad magnets, bad ground on the units, etc.

If you don't want to go that route, start at the magnets and start following the wiring back. Look for corroded connections (most likely) and frayed insulation. If there are wire nuts, take them off and look at the wires...you can get moisture inside the nuts which leads to a reduction in the amps that the wire union can handle.

Most likely the shoes will help a great deal, but, you can't get by on that if you also have issues with wiring or magnets, so, you really are stuck with a "complete" look-see to catch any other gremlins that may be creeping up on you due to trailer age. Fortunately, the RV braking systems are relatively simple and aside from age affecting the components, are reasonably simple to troubleshoot and repair.

M&M · 07-30-2013, 09:24 PM

7-30-13
Thank you to all who replied.
Today, I did test the voltage, amperage, and ground at one of the magnets. The voltage was 12.5 when the gain is set at maximum, the amperage at the magnets is 2.8, and the ground from the backing plates to the frame tested about 2 ohms. I haven't found any frayed or broken wires. I haven't found a ground connection to the frame yet. I did take of the 2 rear drums and sanded off the glaze and gave all surfaces another good cleaning.
I installed the bars for the Equalizer hitch to level the trailer and fine-tuned the brake shoe adjustment; and I finally go lock up all 4 wheels on loose gravel. However, I still think the brakes are on the weak side. Leveling the trailer made a lot of difference when fine tuning the brakes.
I may try a pair of new shoes or complete backing plate on 1 wheel and see what happens, but not until after our next camping trip.

webslave · 07-31-2013, 11:24 AM

If you go with the replacing of parts, remember, you should always do one axle at a time...not just one wheel. Doing a single wheel will result in dangerous sway since that one wheel, on whatever side it is on, will do more "braking" than the other three and will pull the trailer rapidly to that side...

Your electrics sound fine...I'm sticking with the "age" factor on both shoes and magnets for the decrease in the ability to lock them up.

In the "old" days when drum brakes were at their hayday, IIRC, recommended replacement was 3 years/36,000 miles. While your trailer doesn't see as much "duty" as a vehicle does, the age of the brake components still comes into play. The material for the shoes degrades and the magnet's frictional ability to grab the backing plate detriorates.

M&M · 07-31-2013, 03:34 PM

Webslave,

Thanks again for the reply and confirming electric is OK. I will plan to do a whole axil at a time. Did your FunFinder have strong brakes?

M&M

webslave · 07-31-2013, 04:32 PM

Initially, quite strong. I was getting ready to replace all the bearings, magnets, backing plates and shoes after we got back from our last trip (late '11 and we had about 28,000 miles on the trailer and it was at the 3 year mark), but, made the mistake of going to the RV show in Harrisburg... Got a whole new trailer instead!

Would have been a lot cheaper doing the brakes...

One thing you have to bear in mind with any RV. They don't use the "highest" quality of components as they arrive from the factory. The "buying" public insists on buy "cheap", so, that is exactly what they get, and that includes the components used in the braking system. Aftermarket units tend to be of higher quality because the companies want to keep getting your business, but, just like the tires that come on your brand new car, they aren't the best available.