Uneven breaking

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   This is an older thread but I'll add my comments from looking into this issue in depth on my trailer last fall because I think it's pertinent. 
I found that there can be a quite significant difference in braking action between the two trailer wheels, even with brand new properly adjusted brake assemblies. 
One reason is that FR routes the brake conductors (at least on my trailer) from the connector to the left wheel first, then over to the right wheel. And they use insulation displacement connectors which are pretty high resistance. That made about a 20% difference between the voltage delivered to the two magnets. If you ask the techs at etrailer for example they suggest direct equal length runs of 10 AWG wire to each wheel using butt splice connectors. 

A second reason is that there is a manufacturing variation in the magnets resulting in varying internal resistance. Magnetic field in an electromagnet is proportional to the current and the number of turns. 

A third reason is seating of the magnet on the drum.

I happened to have the first two of these factors both work against me on my new brake assembles. I essentially got no braking action to speak of on the right side. The right brake never got burnished in until I balanced the currents between the two sides and tried burnishing the brakes a second time. You can use an ir thermometer to see how much braking action you're really getting on each wheel. The temps reached under aggressive braking should be similar (don't expect identical) on each side if you have things balanced. 

I balanced the currents by running the magnets in series rather than parallel, which guarantees they are the same regardless of magnet and wiring resistance. That reduces overall braking action but I feel like I'm still getting plenty, although I'm not recommending this procedure to others. 

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offgrid Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 23 Jul 2018 Online Status: Offline Posts: 5290	Topic: Uneven breaking Posted: 13 Jan 2019 at 10:13am
	This is an older thread but I'll add my comments from looking into this issue in depth on my trailer last fall because I think it's pertinent. I found that there can be a quite significant difference in braking action between the two trailer wheels, even with brand new properly adjusted brake assemblies. One reason is that FR routes the brake conductors (at least on my trailer) from the connector to the left wheel first, then over to the right wheel. And they use insulation displacement connectors which are pretty high resistance. That made about a 20% difference between the voltage delivered to the two magnets. If you ask the techs at etrailer for example they suggest direct equal length runs of 10 AWG wire to each wheel using butt splice connectors. A second reason is that there is a manufacturing variation in the magnets resulting in varying internal resistance. Magnetic field in an electromagnet is proportional to the current and the number of turns. A third reason is seating of the magnet on the drum. I happened to have the first two of these factors both work against me on my new brake assembles. I essentially got no braking action to speak of on the right side. The right brake never got burnished in until I balanced the currents between the two sides and tried burnishing the brakes a second time. You can use an ir thermometer to see how much braking action you're really getting on each wheel. The temps reached under aggressive braking should be similar (don't expect identical) on each side if you have things balanced. I balanced the currents by running the magnets in series rather than parallel, which guarantees they are the same regardless of magnet and wiring resistance. That reduces overall braking action but I feel like I'm still getting plenty, although I'm not recommending this procedure to others.
	1994 Chinook Concourse 1995 RV6A Experimental Aircraft 2015 Rpod 179 - sold

mcarter Members Profile Send Private Message Find Members Posts Add to Buddy List podders Helping podders - pHp Joined: 07 Apr 2016 Location: Greenbrier, TN Online Status: Offline Posts: 3419	Posted: 28 Dec 2018 at 6:38pm
	Nope, you are not missing anything. Each brake is self adjusting. It could be the source or it could be that brake is not adjusting correctly, but none of us will know until the OP does a controlled test of the brakes. Or somebody does. Lot of leeway here.
	Mike Carter 2015 178 " I had the right to remain silent, I just didn't have the ability."

Tars Tarkas Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 14 Jan 2013 Location: Near Nashville Online Status: Offline Posts: 1452	Posted: 28 Dec 2018 at 6:23pm
	It seems like with the tiniest bit of voltage to brakes each one should lock up on ice. If one wheel still turns the brake isn't working at all. Or am I missing something? I'd check the wires at the brake. Depending on your mechanical ability I'd get someone with the right knowledge and diagnostic tools to check it out. TT
	2010 176 FJ Cruiser

mcarter Members Profile Send Private Message Find Members Posts Add to Buddy List podders Helping podders - pHp Joined: 07 Apr 2016 Location: Greenbrier, TN Online Status: Offline Posts: 3419	Posted: 28 Dec 2018 at 5:17pm
	I wouldn't call it wrong, but the distance from the 7 pin to each wheel is basically equal. It is a source to a magnet. In the case of this post there may be a bit of difference in the self adjusters, but I agree with GlueGuy, really requires a more controlled test, best not to test it on ice or snow. I would elevate trailer , apply brake and see if both wheels lock. If one does and one doesn't time to look at brake that doesn't.
	Mike Carter 2015 178 " I had the right to remain silent, I just didn't have the ability."

David and Danette Members Profile Send Private Message Find Members Posts Add to Buddy List podders Helping podders - pHp Joined: 24 Nov 2009 Online Status: Offline Posts: 1222	Posted: 28 Dec 2018 at 1:31pm
	I had the same problem and took it to a RV repair shop and it was checked out and he said it wasn't a problem. He said to adjust the brake controller a little. He also mentioned DC current can vary, depending on the distance it has to travel. If the DC source to one wheel is closer than the other to the hitch DC connection the wheel closer will have the stronger brake. Hope I explained that right, most likely I don't think you need to be concerned. It could be most all lite weight campers do the same thing. If I am wrong I hope someone corrects me, I don't want to mislead anyone.
	2018 Vista Cruiser 19BFD (2018- 2012 Vibe 6503 (2014-2019) 2009 r-pod 171 (2009-2014) Middle Tn 2014 Ram 1500 Quad cab

GlueGuy Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 15 May 2017 Location: N. California Online Status: Offline Posts: 2702	Posted: 27 Dec 2018 at 5:21pm
	There may be only a slight difference and/or one side might have been on a more slippery surface. So I would suggest that you need a more controlled experiment. One thing to try is to jack up the R-pod and test the brakes independently. A second thing to try is to take it to a parking lot and try the standard trailer brake test by using the trailer brakes to stop both the TV and TT without using the TV brakes.
	bp 2017 R-Pod 179 Hood River 2015 Ford F150 SuperCrew 4WD 3.5L Ecoboost

Stoker177 Members Profile Send Private Message Find Members Posts Add to Buddy List Newbie Joined: 10 Oct 2018 Location: MT Online Status: Offline Posts: 8	Posted: 27 Dec 2018 at 4:51pm
	Hey All, Brought the pod out of storage to let some family stay in over the holidays. The roads here in Bozeman are snowy so it was a slow drive home, but just to test on a slick surface, i checked my break controller and intentionally locked the breaks on the ice at about 7-8 MPH. What I found is only one side was locking up and the other kept rolling. My assumption is that there is an issue with the breaks but wanted to get any advise from folks who may have had the same issue. Many Thanks, All