Trailer Brakes Too Weak

OleBlackyLBZ

Active member
May 22, 2020
276
52
28
So I had a Quest brake controller installed when I started hot shotting. Since day one, my trailer brakes have not been very strong even with the controller turned all the way up, everyone tells me you should be to easily stop the truck from idling forward with just the trailer brake controller test button which I cannot do. Multiple people have also mentioned locking up/squaling the trailer tires with the trailer brakes. Mine wouldn't dream of doing that... Me and a buddy checked the pads and tightened them up since they are adjustable. Still about the same.. anyone have any ideas? I'm sure it's simple this is just kinda my first rodeo with trailer brakes.
 

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
19,161
1,639
113
Phoenix Az
unplug the trailer and have the truck running, with the manual brake controller depressed (as if you are just grabbing trailer brakes only), check voltage at the plug at the back. you dont want a big voltage drop and it happes over time with corrosion. should be around 13v.

if thats all good, get under the trailer and start looking at all the scotch locks they use to connect wires and take them out/change to a sealed butt connector. clean up any corrsion at the ground or other connections as well. the brake wire may also be undersized and causing a voltage drop. wont hurt to see what kind of amps the mags pull at full voltage and upsize the main brake wire if needed.

if all thats good, id look at what magnets are on there, might be undersized for the axles. its possible to put the wrong ones on. Id also make sure there is ) grease on the magnet, in the drum or on the shoes. if it even looks like there was at one time (you have no idea how many guys use the ez lube on the end of the spindle and then blow it all into the brakes), its going to reduce braking. I went through that on my toyhauler cause every precheck as it was built or moved, they pumped grease in and blew it all into the drums.

now by all means, my axles are 7k axles (dual axle on the toyhauler). empty, it wont lock up the brakes but the trailer weighs 12k empty. when you hit the brakes, you feel them hit and slow you down. when i put the tracker in there, its now 14k on the axles and 2k on my pin and braking is greatly reduced. it will still slow me down a hill if i grab them but nothing substantial.
 

Dean E

Member
Mar 30, 2022
70
21
8
Blair, NE
A simple thing to check is your grounds. Both truck side of the 7 pin (the #1 blade) and the trailer side. Apply your truck brakes with the trailer lights on and see if the trailer lights go out or dim when the trailer brakes are applied. If your lights go dim or out when the trailer brakes are applied then you have a weak ground in the system. Dean

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Ron Nielson

Active member
Oct 11, 2009
429
41
28
Berryton, KS
Places that sell trailers, like general utility trailers, have a variety of trailer electric brake magnets. See if they have magnets with more stopping power than your existing units but that will fit and function without any modification. Very easy replacement and great results. James is correct - the connection between the trailer wiring and the brake magnets often is the cause of poor braking performance.
 
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