Trailer Brakes - Page 2

NotyetMHCowner · 06-12-2015, 10:44 AM

I do have the self adjusting brakes. I adjusted them when I had the wheels off, but they were just about right. I just think I need to test the voltage at the truck plug and go from there.

SAABDOCTOR · 06-12-2015, 12:30 PM

Are the trailer brakes adjusted correctly?

SAABDOCTOR · 06-12-2015, 12:31 PM

Sorry i just saw your last post i'll just go camping now

NotyetMHCowner · 06-12-2015, 12:36 PM

I adjusted them up until "heard"them dragging then back off slightly. That is the way I have always adjusted drum brakes. I believe that when they heat up, from braking, tire temperature, etc, they will expand and I don't want them"dragging"and creating extra heat. I may be wrong with this being a trailer and not a vehicle. I have heard they should be adjusted to slightly drag. But if they should be that way, wouldn't they automatically adjust to that level over time?

jsmith948 · 06-12-2015, 02:02 PM

Quote:

Originally Posted by NotyetMHCowner

s. I believe that when they heat up, from braking, tire temperature, etc, they will expand and I don't want them"dragging"and creating extra heat.

When drum brakes get hot, the drums actually expand. This expansion is why drum brakes 'fade' to the point that you lose your ability to brake (the shoes can't put enough pressure on the expanded drums because, at this point, they are out of adjustment). That is the reason why cars and light trucks now have disc brakes. When the rotors get hot and expand the brakes don't fade away. Drum brakes fading away is why there are truck escape routes on many mountain passes. An inexperienced big rig driver using improper braking techniques can get into trouble in a hurry.

NotyetMHCowner · 06-14-2015, 10:42 AM

I pulled the emergency pin today before leaving our site and the truck just about could not pull the fifth wheel. So it looks like the brakes on the camper work just fine. I also pulled the manual lever while driving about 25 mph and it still doesn't stop very well, even set at max (10).

I think the next step for me is to check the voltage at the truck connector.

NotyetMHCowner · 07-05-2015, 02:11 PM

After pulling out of our site at the beach last week, the brakes were stopping a lot harder. I thought, finally, they are working properly. But after a few stops (going through the campground) they went back to normal. We did have some hard rain during the time the truck was sitting there. I am wondering if there is a bad connection, and maybe it made better contact for a few moments while being wet? I have got to get this figured out, as we are leaving for Yellowstone in less than 3 weeks.

When I pull the emergency pin, the brakes just about lock up. The truck could barely pull the fifth wheel. So that tells me that the brakes are working and adjusted correctly. I have the IBC set to 10 which is the max and I don't think that my 2006 model has the extra "boost" setting that the newer ones have. I have used the manual slider at idle speed, 20-25 mph, and highway speeds with no change. It works every time, just not applying as much braking power as it should.

**JRTJH** · 07-05-2015, 04:42 PM

If the brakes "lock up" on the trailer when you pull the pin, chances are that it's not a loose ground or a wire crimp that's not making good contact from the umbilical back. I'm making the assumption that your truck has the "factory installed" 7 pin trailer connector. If so, I'd first crawl under the truck at the rear 7 pin connector and unplug it there. It should be a "snap ring" type lock on the back of the mounted plug. Clean it well, lube it with some silicone grease (di-electric compound) and see if it is any better. Also spend some time cleaning/burnishing the contacts on your truck 7 pin connector and on the trailer connector. Use that same di-electric compound there once they are cleaned. If, by chance, you have a "tap-off" umbilical that runs from the rear 7 pin connector and is mounted in the bed of your truck, check that wiring carefully as well. If you do have two 7 pin connectors, you might want to "experiment" with the other one just to see if braking action is the same with both "truck end" connectors.

NotyetMHCowner · 07-05-2015, 04:50 PM

I do have 2 of the 7 pin connectors. I will try to experiment with the one on the bumper.

I agree that the trailer is probably fine because of the emergency pin locking them up. What puzzles me is that they always work, just not strong enough. I would think that if I have a bad connection, they would not work some times. I would also think that the lights would flicker from time to time, but I have never noticed that.

**JRTJH** · 07-05-2015, 05:06 PM

If you crawl under the back of your truck, you should see a "T" plug connected to the back of your bumper 7 pin connection and then the truck wiring harness (from up front) connected to the back of the "T". both of those connections can, over the years, leak just enough that corrosion has set up in them. It's easy to clean that out, use some copper wool to burnish the contacts, then plug it back together. (Don't forget the di-electric compound).

It doesn't take much corrosion on a brass contact pin to cause a significant reduction in voltage across the plug. If it's not there, I'd start looking at the wiring on the back side of each connector. A lot can happen to corrode wiring from 2006 to 2015. I'm pretty sure it's not a "major issue" or, like you said, it wouldn't be happening all the time. The consistency you describe, to me, indicates a bad plug or corrosion at the plug/terminal.

GOOD LUCK !!!

We are headed toward Yellowstone next week. I expect it will take us 2 or 3 weeks of "lazy cruising" before we get there and current plans will take us through Mt Rushmore, Crazy Horse and Devil's Tower before getting to Yellowstone. My DW won't let me go to Sturgis for the MC ride, so I suppose I'll wind up staying south of there <sigh>

NotyetMHCowner · 07-05-2015, 05:29 PM

Great tips! I will get to those connections this week.

I wish we had that much time for this trip. We are taking about 2 and a half weeks for the whole trip. We are taking 6 days to get there with staying 2 nights in Omaha to go to the zoo. Them coming back through the north and staying 2 nights in Minneapolis for mall of America. Our daughters are coming along with us. I wish we had 2 or 3 months for this trip, but our jobs would frown on that. Haha

NotyetMHCowner · 07-08-2015, 04:10 PM

At idle, I am getting about 13.4 volts at my connector. I am also getting 13.4 volts at the junction box on the pin box. I am getting about 9.3 volts at the axles. I have an insulated under belly, so I don't know where the bad connection is. The wires look good when they disappear into the under belly in the battery compartment. I might try to take down some of the under belly, but I also have a leaking black tank valve that needs warranty work. It would be nice to get it in a dealer and back in less than 2 weeks (yea, right).

Where all does the brake wire go? It is the red wire in the junction box. Is the negative wire just bonded to the frame somewhere? If worse comes to worse, can I run a new wire from the junction box, tie wrapped down the frame rail and tie it into the wire at the axles? I hope to find the problem and get it fixed right, but we are not going to miss our trip to Yellowstone.

jsmith948 · 07-09-2015, 06:24 AM

I'm sure the factory used the correct gauge wire for the length of the run

, but 4 volts is a big drop. Your idea of running an external wire, provided it is of proper size, should solve your problem. You should ensure that the wire is secured so that it can't get pulled loose while underway. The external, temporary 'jumper' would be a good way to troubleshoot and verify the problem lies in the wiring. Please keep us posted as to what you find.

shiggs68 · 07-09-2015, 10:38 AM

The brake wire in the junction box should be a Blue wire coming from the cable. The Red wire from the cable should be your charge wire and will read 13+. Given that, I question if you are measuring the correct wires.

At the brakes, you should only see 7 to 9 volts. The Breakaway switch applies a full 12 volts from your trailer battery to make sure the brakes lock. If you can not lock then from your truck control but have 9 volts, I would say, your brakes need adjusted and you are looking for the wrong answer.

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NotyetMHCowner · 07-10-2015, 08:27 AM

I thought as long as the brake controller was set at its maximum setting, then full available voltage is applied to the brakes?

Some of the connections were a little loose, but nothing to bad. I did cut all the crimp-on wire nuts off and used twist-on wire nuts to make the connections better. When I was testing the voltage 2 days ago, I didn't even think of the house power still plugged into the camper, so that affected my voltage readings. Yesterday, I unplugged shore power and had only the truck connected and my supplied voltage was a little lower. I was seeing around 12.5 volts from the truck at the junction box at the pin box. The wire feeding the breakaway switch from the camper battery was reading more, about 13. At the first point at the brakes, it is now reading about 9.9 volts when set to 10. I get at least 9.5 volts at each of the magnets. Each magnet is drawing 2 amps on one wire and about 3 amps on the other one.

I think, since I fixed some of the connections, that the brakes will work a little better. But I would like to see much higher voltage at the magnets. Maybe I am asking too much.

On thing I noticed was about .6 volt from the negative wire to the frame of the camper. The negative does not attach to the frame anywhere except all the way back at the junction box at the pin box. I am thinking of adding a ground, to the frame, back at the axles. Thoughts?

**hankpage** · 07-10-2015, 10:15 AM

As shiggs68 mentioned ... If you have more than 10 volts at the magnets (from the controller not the break away switch) you have a problem with your controller. Pull your break away switch and then read voltage at the magnet, that is when you should see 12v+, not from the controller. And the blue wire coming into the junction box is from the brake controller. JM2¢, Hank

shiggs68 · 04-16-2016, 05:41 PM

If you are not measuring the same current going into the magnet as coming out, then the magnet is bad. However, it is unusual the all magnets would have the same failure. Based on that, I would have to question your measuring methods. I still believe you are chasing the wrong thing. Your brakes just need adjustment.

TravelingRVDoctor -Sent from my iPad using Tapatalk

Desert185 · 04-16-2016, 06:01 PM

Old thread. My brakes went intermittent, then failed. Bad wiring loom from the stock 7-pin plug to the aftermarket bed plug. Chinese wiring...

dcg9381 · 04-16-2016, 06:36 PM

IF I commit to keeping ours - we're looking at a brake upgrade:
http://www.performancetrailerbraking.com/products

For 2-axle, 8 lug, 7k axles, we're looking at $1750.

Why consider it? The standard brakes on our 13-16k lb RV won't even lock up on gravel/rocks. They're new, fully functional, not grease spoiled... I assume it's just a limitation of how much magnetic force you an put on things. I've got a 2015 truck with a factory brake controller.

I understand disc and hydraulic (adapted to electric) a lot better than electric drum and the *advertised* reduction in stopping distance is impressive. Cutting stopping distance by 60-70% might pay off in a number of cases...

notanlines · 04-17-2016, 03:36 AM

If what you say is true about the brakes not locking the wheels in the gravel then the phrase you used "fully functional" is incorrect. I suspect you need to have your brakes and full braking system checked by a qualified technician. And if you believe some story about disk brakes decreasing your stopping distance by 70%, well maybe you should ask that technician what their opinion might be.

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