5th Wheel brakes SUCK! Help please.

[H3LZSN1P3R]

I was content to just let it be, but now I've completely lost my brakes altogether. I confirmed they are adjusted properly, I've done the burnishing. There are two wires going back to the brakes. One is power (tied to blue wire from truck and 12v breakaway) and the other is ground. They both split into a pair of wires to each axle, which then split again to each side of each axle. At that junction, when I pull the breakaway switch I get 11.67v while sitting still, but can still rotate the tire by hand with pretty much the same amount of force as when not engaged. With just the slider and gain set to 10 on heavy electric, i get 8.5v coming out of the trucks 7-pin connection but only 3.64 at the junction of the wires near the axles.


I've ohmed all the wires and there is virtually no voltage drop.

If I'm getting power to the brakes, why aren't they engaging? I can hear them, they just aren't doing anything

May be a bad connection where the 7pin cable splits off or one of the magnets are shorting out

 

[AF_Hemi]

May be a bad connection where the 7pin cable splits off or one of the magnets are shorting out

Would one of the magnets cause the other 3 to not work also? I thought about the 7-pin, but how does that explain why they won't work with the breakaway which bypasses the 7-pin

 

[H3LZSN1P3R]

Would one of the magnets cause the other 3 to not work also? I thought about the 7-pin, but how does that explain why they won't work with the breakaway which bypasses the 7-pin

If one is drawing more power it could keep the others from working but usually you get an error on the dash, when i say where the 7pin cable splits off usually both the blue brake wire from the 7 pin and the break away switch wires tie in to the service wire for the trailer brakes so that connection could still be the issue, i wish they would use junction boxes like this it makes diagnosing issues much easier

 

[smcleod417]

I'll tell anyone, if you can afford the cost, upgrade the brakes on any 5th wheel/travel trailer to electric over hydraulic disc's. There is absolutely no comparison with electromagnetic brakes. I converted my trailer to disc's and the best description of how well they work .... after a few trips you stop even thinking about the trailer when braking, even when braking aggressively.

 

[AF_Hemi]

I'll tell anyone, if you can afford the cost, upgrade the brakes on any 5th wheel/travel trailer to electric over hydraulic disc's. There is absolutely no comparison with electromagnetic brakes. I converted my trailer to disc's and the best description of how well they work .... after a few trips you stop even thinking about the trailer when braking, even when braking aggressively.

If you've got a couple thousand dollars extra if gladly upgrade. But in the meantime, I have what I have and my extra few thousand is getting burnt and going out the tailpipe on this trip

 

[H3LZSN1P3R]

I'll tell anyone, if you can afford the cost, upgrade the brakes on any 5th wheel/travel trailer to electric over hydraulic disc's. There is absolutely no comparison with electromagnetic brakes. I converted my trailer to disc's and the best description of how well they work .... after a few trips you stop even thinking about the trailer when braking, even when braking aggressively.

I have put disks on floats of mine but there is nothing wrong with a properly working set of drums in most cases

 

[KneeDeep]

I was content to just let it be, but now I've completely lost my brakes altogether. I confirmed they are adjusted properly, I've done the burnishing. There are two wires going back to the brakes. One is power (tied to blue wire from truck and 12v breakaway) and the other is ground. They both split into a pair of wires to each axle, which then split again to each side of each axle. At that junction, when I pull the breakaway switch I get 11.67v while sitting still, but can still rotate the tire by hand with pretty much the same amount of force as when not engaged. With just the slider and gain set to 10 on heavy electric, i get 8.5v coming out of the trucks 7-pin connection but only 3.64 at the junction of the wires near the axles.


I've ohmed all the wires and there is virtually no voltage drop.

If I'm getting power to the brakes, why aren't they engaging? I can hear them, they just aren't doing anything

Edit: even with gain on 10, the slider will not slow/stop the rig at 5 mph

Maybe a bad ground connection. If the ground wire from the brakes all go to the same common ground point on the trailer with a screw though the frame, you could remove the screw and make sure there is a clean connection (no paint contact).
When you pulled the breakaway did you get 11.67v at the brake wires going into a wheel ? If so, did you measure using both the hot and ground wires going into the wheel or did you use frame for your ground?

 

[AF_Hemi]

Maybe a bad ground connection. If the ground wire from the brakes all go to the same common ground point on the trailer with a screw though the frame, you could remove the screw and make sure there is a clean connection (no paint contact).
When you pulled the breakaway did you get 11.67v at the brake wires going into a wheel ? If so, did you measure using both the hot and ground wires going into the wheel or did you use frame for your ground?

I checked the ground connection where the 7-pin connects with the trailer brake ground up in the kingpin. When testing the power at the brakes I used both the ground wire and a separate ground screw and both had the same reading.

 

[MEGA HO]

If it were me, I'd Jerry-rig a direct connection from a portable 12V battery direct to the break wires at the trailer plug and then direct to a break cylinder (or at that junction you're talking about) and check if I could spin the wheels.
If you have such a voltage drop at the junction vs the trailer plug, the wire gauge maybe too tiny and you just don't have enough Apms to energize the cylinders, or something else is screwed up with the wiring... Best way is to test directly with 12V at the cylinders and then work your way backwards from there.

Did you try towing a different trailer with your truck by the way?

 

[loveracing1988]

2018 Grand Design 303RLS rolling on Dexter 5200lb axles, plain old drums.

I have a 2019 with the same axles and I tow on light around 7.5. I have definitely locked the camper tires up before. In any kind of city driving when the brakes get some heat in them I have to turn the brakes down so it doesn't jerk the truck back...

 

[loveracing1988]

If it were me, I'd Jerry-rig a direct connection from a portable 12V battery direct to the break wires at the trailer plug and then direct to a break cylinder (or at that junction you're talking about) and check if I could spin the wheels.
If you have such a voltage drop at the junction vs the trailer plug, the wire gauge maybe too tiny and you just don't have enough Apms to energize the cylinders, or something else is screwed up with the wiring... Best way is to test directly with 12V at the cylinders and then work your way backwards from there.

Did you try towing a different trailer with your truck by the way?

This, try towing with a different truck or tow a different trailer with your truck to verify the brake controller and truck wiring is working properly.

 

[smcleod417]

If you've got a couple thousand dollars extra if gladly upgrade. But in the meantime, I have what I have and my extra few thousand is getting burnt and going out the tailpipe on this trip

Definitely understand the sentiment. Disc brake conversions aren't cheap and fuel $$'s are eating up a lot of discretionary spending.

 

[AF_Hemi]

For anyone still willing to offer some advice, here's an update:

I replaced the trailers 7-pin connector to a Pollack single pin (new style as called for in the Ram TSB).

I adjusted all 4 brakes to have a minor rub when no brakes are engaged

The system has 1.2 ohms of resistance as measured between the ground and brake control pins on the 7-pin connector.

Each axle (2 brakes each) is getting 6.65 amps as measured at both the junction box in the king pin and at the axles.

From what I can see, all magnets are working, voltages are correct (12.67v with breakaway, 8.5v from brake controller at 100% while sitting still and variable voltage depending on brake %), amps are correct, and no shorts anywhere in the system (ohms are very low).

I can barely turn each wheel on the front axle but can't turn either wheel on the rear axle when 100% applied.

All that and there is no noticable brake action when moving either from 5 mph or 65 mph. I squeeze the trailer brake slider and feel nothing.

Any other troubleshooting advice?

 

[Brutal_HO]

Couple things.

You should not be able to turn a wheel by hand with the emergency cable/pin pulled. No way, no how. I can tell you with certainty, the brakes will lock with full, constant, not PWM 12V applied from the RV battery. Ours on our old 04 Cougar got hung on the hitch once and stopped us dead in our tracks making a turn on a small town main street.

What color are the magnet wires? The 6K axles should have white or black wires (green wires are lower power magnets).

Ensure the wiring is in parallel and not in series.

Each magnet should have one lead tied to power, and one lead tied to ground - preferably the ground wire and not a chassis or frame ground.

To properly measure each magnet resistance, you need to disconnect and measure them individually. The combined resistance doesn't tell you much if one is shorted internally. They should each measure 3.2-3.5 Ohms.



Is it possible the axles were installed backwards? That would put the brake assembly backwards. The actuator arm and short pad should be in the leading position, the long pad in the trailing position.

(left side = LH assembly shown)

 

[AF_Hemi]

Couple things.

You should not be able to turn a wheel by hand with the emergency cable/pin pulled. No way, no how. I can tell you with certainty, the brakes will lock with full, constant, not PWM 12V applied from the RV battery. Ours on our old 04 Cougar got hung on the hitch once and stopped us dead in our tracks making a turn on a small town main street.

What color are the magnet wires? The 6K axles should have white or black wires (green wires are lower power magnets).

Ensure the wiring is in parallel and not in series.

Each magnet should have one lead tied to power, and one lead tied to ground - preferably the ground wire and not a chassis or frame ground.

To properly measure each magnet resistance, you need to disconnect and measure them individually. The combined resistance doesn't tell you much if one is shorted internally. They should each measure 3.2-3.5 Ohms.

View attachment 39836

Is it possible the axles were installed backwards? That would put the brake assembly backwards. The actuator arm and short pad should be in the leading position, the long pad in the trailing position.

(left side = LH assembly shown)

View attachment 39835

Thanks for the detailed response. Some great info here.

I agree that breakaway should lock them up. They will lock hard enough to not be able to turn by hand (the rear axle anyway, the front I can still barely turn).

Wires are all white. Coming from the truck is the blue trailer brake controller wire which connects to a red wire that runs from there to back at the axles, splits into 2 white wires (front axle and rear axle) then each of those splits into 2 (left side, right side). The ground is the same, all ground coming from the wire, not a chassis screw. So yes, it's wired in parallel.

I hadn't considered them being installed backwards, and although I'm sure very unlikely, it's something I could check so I guess I'll pull the wheels apart.

 

[Blythkd1]

If the brake wires are coming through the backing plate on the back side of the axle, they're correct.

As far I know they're meant to work in both directions nowadays but since they do make 2 different brakes and specify RH and LH, to me that would imply that they're designed to perform better in one direction than the other.

Sounds like you've definitely got a weird deal going on there.

 

[Brutal_HO]

The more I think about the way those magnets work inside the drum, the more I think it's possible you could possibly turn the wheels by hand.

The magnet tries to pull itself onto the inside face of the drum, causing the attached arm (lever) to push the pad outwards. When you pull off a wheel/drum, see if the magnet face and drum show even wear. If the drum surface is badly pitted, you could have an issue where the magnet is providing enough "grippage" to the drum.

You can also identify the "never-adjust" version by the presence of that cable and a flip[per tab that engages the adjuster. No cable = not self adjusting.

 

[GatorHunter]

I have a 2022 Ram 3500 pulling a 2022 5th Wheel, GVWR is 11k and it has tandem dexter 5k axles with electric drum brakes. In the truck's settings, I'm on Heavy Electric with gain set to 10 and it still won't lock up the trailer brakes. I had an emergency stop the other day and had to pull onto the shoulder to keep from plowing through a couple of cars because I couldn't stop. It didn't even feel like a hard stop. Something isn't right. I don't know what else to check/do. I can't even get the stupid things to lock up on gravel!

I just went thru this on my Keystone Volante TT. The brakes need to be “burnished”. Pretty involved process of driving, dragging, driving, etc. Mine aren’t 100% but a LOT better. Now I start around 4 on heavy and after a few brakes I can reduce to about 2.

 

[GatorHunter]

I've pulled many new campers and never saw one that would lock up the brakes, and certainly not on pavement, usually not on gravel either. I'm not saying that you don't have something wrong but it you had them all smoking, it might be a case of you've got what you've got. I've backed up and pulled up multiple times and delivered many units 1500+ miles and sometimes they feel a little better at the end of the trip but still not strong. If you're feeling something when you apply the trailer brakes, that's pretty typical in my opinion.

First thing I do when I hook up a new RV is make sure my gain is set to 10.0 as some of my trailers that I pull when I'm home have very good brakes so I back the controller gain off. I always pull new RV's with the gain set to 10 and never have too much brakes. How heavy is your camper? I see you mentioned 5k axles so I'm guessing the brakes are no larger than 2 x 12's. I just pulled a triple axle 5th wheel a couple weeks ago that probably had the same axles under it and 6 brakes weren't even doing much. I'm just saying don't get your hopes up.

Mfg’s aren’t burnishing in the brakes. So sending out safety hazards and either dealers aren’t aware of it or just don’t care.

 

[AF_Hemi]

I just went thru this on my Keystone Volante TT. The brakes need to be “burnished”. Pretty involved process of driving, dragging, driving, etc. Mine aren’t 100% but a LOT better. Now I start around 4 on heavy and after a few brakes I can reduce to about 2.

Unless I did it wrong, I did this. I basically just drug the brake until they each got 350-400 degrees and were smoking.