2014 F350 DRW towing 16,000 lb 5th wheel. Plenty of experience towing and I'm and on my 3rd Super Duty. I've done a couple searches but can't find what I need. I just completed installing new wheel bearings, new brake assemblies and hubs turned, all around. In following break in instructions for new brake assemblies I was burnishing the brakes. Instructions were to get truck and trailer to 40 MPH and use the TBC to apply the brakes and slow the truck to 20 MPH and to do it 40 times. Hard to do in the ATL area traffic but I made a good effort at it. As the brakes began working I noticed an intermittent result. The brakes would at times activate and the stopping power was impressive. At other times the squeeze of the TBC would do nothing. I have battery voltage all the way back to the brakes when parked and using the TBC. It is my understanding that I need to measure the AMPS when brakes are applied. I can't do that unless the truck is moving at something over 11 MPH. So, is there a way for the DIYer to measure amps on the TBC. Can I clip a couple wires to the ground and brake connections at the 7 way and run them to the cab to use an amp meter on them? Would that give me a reading or must I figure a way to insert the amp meter in to the actual braking system. Also, has anyone experienced an intermittent TBC? My truck brakes have worn a lot faster than I expected so I may have had this problem since new. It is possible because I'm an old man and experienced and do not make many hard stops. Thank you in advance for help.

 

I think you can get someone to use the manual slide on the TBC while you are at each wheel checking for amps.

Ideally 3 amps at each wheel is what you should see.

I also know there is an adapter that you can plug into the truck side 7 pin and check all pins. I don't know if it would give a reading on the level of output.

I am getting ready to look at mine (trailer brakes) over the winter and I maybe redoing them as well. I've got close to 30K on them so they should be getting there. I noticed that mine was not braking as good as it was on our trip back from Maine last month.

 

hi senix hope you are well Dont the amp output increase as pressure is applied to the brake pedal. If so is that also true of the TBC. I suspect some sort of intermittent problem If thats the case I don't know if I would trust any stationary test. I have a lot of miles on the trailer and the brake shoes were barely worn I replaced badly worn front truck brakes at 40,000 and rear at 52,000. Seemed early to me based on my other trucks. Those two clues and the problem with the test are all I have. Rig seems to stop OK but I don't think I've ever had a hard stop with it. Do you suppose those magnets would stop grabbing when over heated? They got pretty hot during the burnishing. Hot enough to activate the TRAILER WIRING FAILURE warning. Had to look that up in the owners manual. lol.

 

Stanley, Got to thinking on this and then I called this thread that maybe helpful
https://www.ford-trucks.com/forums/s...06&postcount=1

 

Now as too getting hot during the brandishing process, I'd say they are working good.

So your issues maybe truck side.

As a related matter on my truck, I too replaced my fronts at around 45K. My rears are still fine. I probably have 30K on my 5th wheel.

Last time I checked my trailer brakes were fine and I could tell they were all working well. It is my project this winter to check them all and do a repack of the wheel bearings again.

 

Thank you Senix