Help with weak brakes

[eebj01]

Originally Posted by bobfrommaine

If this is solved, congratulations, if you're still troubleshooting -
The pucks do require a fair amount of current, and often while the power comes through the 7 or 9 pin plug, the ground may just be to the trailer frame. Thus, the pucks get plenty of voltage, but not much current. If you have an inductive current probe for your multimeter, I'd split the loom going from the hitch plug to the trailer and measure the current. If current is too little, install a ground (negative) wire from the brakes to the plug and then from the plug to the battery negative. Those trailer brakes should drag the tires, if they're not, something is wrong and it is probably insufficient current.
Good luck. Bob

I tried a ground wire from the truck to the trailer. It didn't help at all. I like your idea of running a ground wire to the battery to tie it all together. I think I will give that a try this week

[bakedalaskan]

Your brakes are probably just fine. Modern brake controllers do not work like the old add on controllers that just apply voltage. The computer takes into consideration the speed of the tow vehicle and the amount of deceleration asked for. If you just reach down and try the manual slide lever without trying to slow down with the service brakes almost nothing will happen. You can make adjustments to how the controller works through the information display on the dash but you have to study the owners manual and complete a graduate level engineering course to understand it. Your brake controller will attempt to apply anti sway and basically will not lock up the trailer brakes unless you panic stop and even then the computer will make decisions on what to do. The system works well and saved my bacon once in the snow when I misjudged a decreasing radius turn. Disconnect the trailer plug from the truck 7 pin then pull the breakaway lanyard. Try to pull away. The brakes should be full on.
Braking effort should feel normal in normal driving conditions. ( Obviously you are much heavier with the trailer connected so normal becomes relative.) If during normal stops you feel like you have to apply more brake pressure than you do without the trailer; increase the gain. If it feels like you are using less brake pressure reduce the gain until you find a setting that feels about right.

[Old-Biscuit]

When was last time you manually adjusted your brakes???

Drum brakes need to be properly adjusted to properly function when braking

See pgs 12 -22
https://www.dexterpartsonline.com/fi...e%20Manual.pdf

[bpu699]

Originally Posted by Old-Biscuit

When was last time you manually adjusted your brakes???

Drum brakes need to be properly adjusted to properly function when braking

See pgs 12 -22
https://www.dexterpartsonline.com/fi...e%20Manual.pdf

Its interesting that air drive s-cam drum brakes in trucks/class A don't have any adjustments like cars do...

[URTHllc]

Originally Posted by bpu699

Its interesting that air drive s-cam drum brakes in trucks/class A don't have any adjustments like cars do...

Airbrakes do have adjustment, you chock the wheels, release the brakes then on the slack adjuster you tighten it down all the way then loosen about 1/4 to 1/2 turn. That gets the pads just off the drums.

[bpu699]

Originally Posted by URTHllc

Airbrakes do have adjustment, you chock the wheels, release the brakes then on the slack adjuster you tighten it down all the way then loosen about 1/4 to 1/2 turn. That gets the pads just off the drums.

True.

On a car with hydraulic brakes the adjuster is opposite the expansion cylinder. On a diesel the s-cam does both...

The s cam adjuster primarily sets the angle that force is applied at. And self adjust as the pads wear.