Problems after changing trailer brakes

[Crunch]

I am running a Tekonsha Prodigy controller, whichever one was current in 2006. It is connected with the pigtail add-on that came with my truck. It's worked perfectly since the day I bought it. But on my last out of town tow, about 3/4 of the way to the destination I noticed that I was getting an intermittent overload code (OL), which sometimes turned into a short code (SH), and occasionally the not connected code (NC). Sometimes applying the brake lightly would get things back in order, but the problem persisted intermittently until I dropped the trailer off a few days later. I wasn't too worried about the return trip with the trailer unloaded, but it's 12,000lbs on the outbound side so that's a real concern.

After finishing the trip the friend who owns the trailer and I checked all the wires and connections. We found a few spots where it looked like the insulation was a bit worn, so we taped those up, but the problem persisted. Next we started to check the amperage to the brake magnets. Left rear magnet (dual axle trailer) read low, and the right rear magnet read el zippo. Even though the brake pads were still in decent shape we figured it was a good time to change it all at once, rather than just change the magnets. Magnet cost was just under $30, while the complete assembly was just under $50. New magnets, new pads, new springs. No question on which route to go here.

But this is where the problem starts. We got the new brake assemblies on correctly, i.e. left and right. The magnets are at the bottom, attached to the swing arm which pulls to the back of the trailer when rolling forward. The brake pad on the front of the assembly is pushed out. We got all four on, and adjusted them so that when the wheel was on it would spin about one revolution when the trailer was jacked up and no brakes were applied. We figured that was about the right amount of friction. But when we road tested the trailer the brakes barely slowed the truck down with the Prodigy set on 5, and using the lever on the brake controller. It did better at 12, but still didn't lock the wheels up like we expected and didn't really hold the truck still while stopped in drive and using the brake controller lever. When the wheels were jacked up off the ground the brake controller level would stop them very quickly, but we could force the wheels to rotate using a considerable amount of push. So it sounds like a low current problem at this point.

We then adjusted the brakes so that the wheel only spun about half a turn, and got the same results in the road test (which was actually on gravel and grass). What else could be the problem? The only thing left I see in the equation is the Prodigy brake controller, but I don't know anyone who has had a brake controller fail. We had to stop because it was getting dark, but we adjusted the brakes back to about a one-spin tension on the springs, and my friend who owns the trailer is going to hook it up to his truck tomorrow and see how it works with his Prodigy, which is an older model. Is there something we missed when replacing and adjusting the brakes, or is it most likely going to be my Prodigy failing. I'll also add that I moved a couple of years ago and the driveway at my new house is sloped downward from the road. Because i don't like to back out of the driveway I back into it when i return home. When I come to a stop I notice that the "_ _" code shows up on the Prodigy (no trailer connected). It also comes on when I leave the driveway, but goes off right when I get on the road. The brake controller is mounted parallel with the truck frame, so I've just chalked the code up to the angle of the truck. On level ground the brake controller is level.

Anyone have some info on what is going on here? Thanks in advance.

 

[Tuesdak]

Start looking for a bad connection in the trailer plug both the trailer and truck. I would look really hard at the ground wire for burn out or bad connections. Even the ground strap from frame/body to engine is suspect. Check the wires on the circuit breaker for the brake controller on the truck. The hitch is a very intermittent bad ground... Thus the suggestion to check the ground in the trailer plug.

How is the break away battery or any battery on the trailer? Discharged or shorted can put a large load on the ground and other wires. Especially if the battery is stone cold dead and the break away switch is on. Aka Trailer brake controller tries to charge battery through break away switch.

Where are the brake magnets grounded on the trailer?

 

[Hoefler]

The new brake shoes will take several applications to burn/wear in. The shoes donot match the drums, they will wear in, and require several adjustments over the next 1000+ miles to be fully seated. If driving highways, it will take longer than stop and go traffic.

 

[B.G. Smith]

Just a thought. Does your controller have the multiple choice of electric, electric over hydraulic, etc and boost setting? Also if the shoes were different sizes the long shoe goes on the rear. bg

 

[Crunch]

Start looking for a bad connection in the trailer plug both the trailer and truck. I would look really hard at the ground wire for burn out or bad connections. Even the ground strap from frame/body to engine is suspect. Check the wires on the circuit breaker for the brake controller on the truck. The hitch is a very intermittent bad ground... Thus the suggestion to check the ground in the trailer plug.

Where are the brake magnets grounded on the trailer?

The electric connections are all run off a primary cable, which is about as big around as your thumb. The ground branches off near the tongue, and grounds to the trailer frame. I believe this grounds all the lights and the brake magnets. The magnets have two wires that extend out the back of the brake assembly unit. They just close the circuit, so there is no difference in how they are wired.

How is the break away battery or any battery on the trailer? Discharged or shorted can put a large load on the ground and other wires. Especially if the battery is stone cold dead and the break away switch is on. Aka Trailer brake controller tries to charge battery through break away switch.

The battery was switched out last year, and the breakaway pin is still in the slot. But in mentioning that you have provided another way to test the brakes. If we hitch the trailer to the truck but don't connect the trailer plug, then pull the breakaway pin the brakes should get full juice to the magnets and lock up the wheels. If we then put the truck in drive the brakes should hold it in place, and the tires should skid when the accelerator is pressed.

Just a thought. Does your controller have the multiple choice of electric, electric over hydraulic, etc and boost setting? Also if the shoes were different sizes the long shoe goes on the rear. bg

I'm not sure of the Prodigy model number, but I can only set the current level (from 1-13) and boost level (B1, B2, B3). Yesterday I was testing in on 13, B3. The shoes were the same size, and the brake assemblies (from E-Trailer) were all labeled LH/RH. It was interesting to finally see how magnetic brakes work in reverse: The rear brake shoe moves, but a lot less than the shoe on the front.

The new brake shoes will take several applications to burn/wear in. The shoes donot match the drums, they will wear in, and require several adjustments over the next 1000+ miles to be fully seated. If driving highways, it will take longer than stop and go traffic.

We discussed the possibility of a break in period. But if the brakes don't slow the truck down at idle speed when the brake controller lever is pulled and it is set to maximum power, they aren't providing sufficient braking to be safe on the road. The drums are in good shape, with no scoring. BRAKING NEWS: While writing that last sentence I got a call from the guy who owns the trailer. He ran the trailer in to the place where he bought it, and the tech checked out the brakes. He concurs with you that they need to be broken in, and had my friend drive around their shop a dozen or so times. When he called he told me that the brakes are getting better, and he has been able to lock the tires up on level 5, B3. That's better than I was able to do yesterday, or what he was getting out of it this morning. So at this writing is looks like that may have been the case. That kind of surprises me, because breaking them in was only a passing idea yesterday, and something I've never experienced with brakes. My experience has always been that you change them, and it's a brand new day in the stopping world. Last night I was already preparing to find a new brake controller in a world where they aren't as common in aftermarket stores.

Thanks for all your help everyone.

 

[Crunch]

The new brake shoes will take several applications to burn/wear in. The shoes donot match the drums, they will wear in, and require several adjustments over the next 1000+ miles to be fully seated. If driving highways, it will take longer than stop and go traffic.

You were spot on with the diagnosis. Me and the friend who owns the trailer took turns driving it around and working the brake lever. They actually wore in fairly quickly. Last night I hitched up a 12,000lb. load and had no problems running it 500 miles. Gently using the lever even stopped the load completely. Now they are back to 100%. Lost a lug nut off a trailer wheel somewhere along the trip though. First time that's ever happened to me. Not sure if that's one we missed, or it just didn't get torqued down right.

 

[AMink]

New brakes, as you discovered, take 20-30 or more stops to wear in. I just put new brakes on our 5th wheel TH and drove around town using the lever to operate the trailer brakes. 40mph to 20mph or so with time to cool off in between. By the time I was done I was on Heavy Electric with 3.5-4 gain on the built in controller. After 200 miles jack the trailer up and readjust. You'll also want to retorque the lug nuts after 50-100 miles after putting the rim back on.