Redwood 39MB trailer brakes weak

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New member
Jul 31, 2019
I have a 2015 Redwood 39MB with a Moreryde king pin towed by a 2019 Ram 3500 DRW. I have only pulled the 5th wheel one time and the trailer brakes did not seem to work. I adjusted the integrated brake controller to 10 with no result. Slowed down to an idle and pressed the emergency button on the the controller. The trailer slowed but did not stop. The trailer should stop the truck. Anyone have any ideas?
Have you EVER adjusted the brakes?
IF your positive everything is up to snuff then I would suggest converting to disc brakes.
I would pull at least one wheel to check the pad wear. I would guess the brakes are just out of adjustment but since it's new to you you should confirm the pads aren't worn out before attempting to just adjust them.

I had the same issue with my trailer, and when I pulled the wheels founds the pads were barely worn but way out of adjustment. I elected to repack the bearings and install all new brake assemblies with self adjusting brakes - total cost for parts under $300
Those are electric brakes, so the most likely culprit is simply poor power to the wheel magnets. That typically results from poor wire connections from truck to trailer or on the trailer wiring itself (corrosion, etc).  A big trailer like that can draw 30+ amps to fully activate the brakes, so solid connections and large gauge wires are important.

You might also have an inadequate power source on the truck, but presumably the factory (?) brake controller and its12v power source would be up to the job.

Last, it could be the trailer brakes themselves, but a 2015 trailer should not be worn out yet.

One simple check: when stopped and the trailer disconnected, pull the breakaway switch handle out and verify that the trailer brakes lock up as they should. This uses the trailer battery and trailer wiring only - no truck involved.
I had a similar problem.  When I bought my FW used, the seller told me the trailer brakes could easily stop the truck.  When I hooked it up to come home, the brakes did stop the rig from about 5 mph, but not very fast.  (gain at 10)  I have checked several things, and in desperation, I got some contact cleaner spray. Before our last trip,  I soaked both the truck and FW connectors, allowed to dry and hooked up.  I tested the brakes pulling down the drive, and almost got a whiplash!  As Gary said, poor power to the wheel magnets.

It may not be your problem, but it may be worth $10 for some contact cleaner to find out.
grashley said:
I tested the brakes pulling down the drive, and almost got a whiplash!

I know that will happen with the older style brake controllers. They had a pendulum inside the controller and when going down a steep driveway and you barely apply the truck brakes, the pendulum swings forward applying the trailers brakes thinking that you are trying to stop fast. To stop that, just back off on the gain or leave the electrical cable disconnected till you're on a level surface. I don't know how the newer controllers work today.
Your age is showing, Rene!  Pendulums as inertia detectors went out of style about 30 years ago. They are solid state accelerometers these days and not affected by up/down angle.  Some of the cheaper brake controllers persisted with pendulums for several years, though.
Gary RV_Wizard said:
Your age is showing, Rene!  Pendulums as inertia detectors went out of style about 30 years ago. They are solid state accelerators these days and not affected by up/down angle.

Talk about putting salt in a wound. I have feelings you know.
Yes I agree,  but there may be some still around.
Gary RV_Wizard said:
Your age is showing, Rene!  Pendulums as inertia detectors went out of style about 30 years ago.

Back in Rene's day, this is how brakes worked  ;) ;D
Your truck has settings for light or heavy trailer. Its in the menu system on your screen. Options are electric or electric over hydraulic, light or heavy. My 2017 Ram 2500 has this which I just found out with my new 5th wheel. You need to know the type of brakes that are on the trailer.
I know about the adjustment.  Initially, braking was  so weak that my gain at 10 gave some braking.  That was where it was set when I checked them.  Then I readjusted them down to a reasonable level!  My comment was to show the effectiveness of the cleaning.  I prefer NOT to use Rene's braking method.  With the high stance, I could not get my foot to the ground and stay in the driver seat!
Im a bit late to this party, but here it goes... There were some folks over on the redwood forums that experienced that very same issue. It was being caused by inferior wheel seals, the bearing grease blew out the rear and was over the shoes... That effected the braking as you can assume....

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