I have a 2015 F250 diesel with Integrated Trailer Brake Controller. I'm pulling a 9500 pound fifth wheel trailer with electric brakes (not electric over hydraulic). I can set the Gain Adjust to max, which is 10. And, I can set the Trailer Brake Effort (TBE) setting to the third setting which is "Heavy." But, while I get some trailer braking action, the trailer brakes don't seem to come anywhere close to locking up. Locking up would seem to be expected with gain and TBE set to max. Do I have a problem or is what I'm experiencing normal? Is there a process for checking to see if you are getting voltage to the trailer brakes?

 

How are the brakes on the trailer? Have they been inspected?

 

I read you should be able to skid the tires (lock the 5th wheel's brakes) by squeezing the TBC controls when moving on gravel at 20 mph or so. I am not near the max settings, but at a setting of about 4.5 I can do this. I suspect you could have an issue with some of the trailer brakes not all working (breaks in wires at the wheels), too much voltage drop from TBC to the brakes (wiring or connector issue), or some other issue. I had the same problem and found that only one wheel was actually working correctly on my 5vr. After rewiring and repairing no issues. Good luck!

 

My car hauler brakes won't lock up with the brake pedal unless I'm on gravel or the trailer is empty & I'm going down hill. They will lock up if manually apply the brakes using the controller.

 

newer brake controller (Ford) is connected to the anti-brake system of truck...


on gravel road.. manually pull brake lever from 10 to 20 mph.. brakes MAY lock trailer brakes.. "MAY"...

 

With Trailer Brake Effort and Gain set at max and going down a gravel road at about 20 mph, with my foot off the brake pedal, I fully moved the brake controller lever. The trailer brakes slowed me down but nothing close to locking up. Can you measure the voltage at the wheels when some one activates the controller in the cab to see if you are getting the correct voltage to the brakes? What would the voltage be?

 

You will need to systematically check the voltage as you go back toward the brake axles from the truck connection. This way, you will be able to determine where a possible break or grounding in the wire could be.


Does your brake controller give you a readout of voltage when you pull the lever all the way over? If so, that can be your standard of measure.

 

I've had the same symptoms as the OP in regards to the brakes locking up on gravel at 10 or 15 MPH on our 9000 lb. fifth wheel camper.

Last summer I decided to repack wheel bearings on the fifth wheel and while I was at it I replaced all brake components (magnets, shoes, hardware and backing plates) on both axles with new from NAPA. There were a couple of quality grades to choose from and I went with what is supposed to be the top grade components. We pull the camper about 1500 miles per year and the braking power had diminished noticeably over the previous 2 years.

I checked the voltage at the trailer wheels with the truck engine idling and all 4 had, at the minimum, 11 volts showing on my voltage tester with the integrated controller set at maximum braking power to the camper wheels. When I test towed the camper for the first time I was very disappointed. At around 10 to 15 MPH I would apply the trailer brakes full on and they did not lock up on gravel. However, at 50 MPH when I apply the camper brakes full on there is significant braking felt. They whoa the truck and camper down but nowhere near what we thought they should. But, after consulting with several folks that are somewhat more seasoned at trailer towing than I, and a local RV dealership I came to the conclusion that the brakes were operating within acceptable parameters.

They all said if there is adequate voltage at the wheels and all other components are up to snuff then the braking we have is probably as good as can be expected.

The only other point of reference I personally have is our tandem axle, 16,100 lbs. capacity goose neck flat bed equipment trailer that is just a few years old. The goose neck will lock up all 4 wheels on gravel at 20 MPH with no hesitation at all. In fact, it will lock at least a couple wheels at slow speeds on pavement. The empty weight of the goose neck is approximately 5500 lbs. However, the axles under the equipment trailer obviously are rated at a much higher total weight capacity than the camper. I attribute the significant difference in braking power to the added capacity of the axles which no doubt have heavier duty brake components than the camper.

The only component at the wheels of the camper that I didn't replace with new was the surface plate that the magnets ride on. There was small irregularities across the face of the magnet contact surface but nothing that I thought was significant enough to warrant replacement.

In conclusion I would say you may be getting all the braking power that you can realistically expect. At least from our experience I believe that may be the case.