Electric brakes, how it works

[gearhead]

I’m kinda thinking the brake controller outsmarted the inspectors.

[sourdough]

Originally Posted by Island Eddie

I have my TV listed in my profile under "about me"....
Does it go elsewhere?
I do need to update my trailer tho

Goodness, I never said tow/haul was instead of brakes, that makes no sense.

I see folks riding their brakes down long grades, and I always have to answer my wife's question: "Those aren't are brakes are they?"

The signature will show when you make a post which helps everyone.

https://www.keystoneforums.com/forum...ad.php?t=52977

[Hugo-H]

my brakes don't have enough braking power when I was at the vehicle inspection... Since my van (E350) didn't have a brake controller installed from the factory (but is pre-wired), then my question was about the possibilities and the how-to's, to determine the problem...
Secondly, my van doesn't have a tow / haul mode...and that makes driving in the mountains little bit less relaxing.. Even squeezing to 100% still does not give enough braking power...
Can it be the the brake shoes are "vitrified"? (glazing of the shoes)... but how does that look? (pic included of one of the brake shoes on my TT)
Today I will check on the current used by the magnets after pull out of the breakaway pin...

[chuckster57]

You might get a little better braking if you scuff the pads with sand paper.

[Hugo-H]

what kind of sand paper may i use?... 100...500...1000?
I need to sand the drum inside too?

[chuckster57]

Originally Posted by Hugo-H

what kind of sand paper may i use?... 100...500...1000?
I need to sand the drum inside too?

I use 150-180. If the inside of the drum is shiny then yes do it also. Make sure to use brake cleaner with a CLEAN rag after sanding. If the magnet surface is glazed or the drum surface is glazed you can sand the drum surface but I would just clean the magnet.

I do all sanding by hand.

[sourdough]

Just glanced through this thread again and thinking maybe we back up a bit...it seemed to go in the direction of some kind of electronic malfunction but...

Everything worked fine until you worked on the brakes....now they don't operate properly is what I'm getting. My first thought is did you release tension on the shoes prior to removing them, and if so, did you re adjust them? If you did and they still don't seem to work, jack up the trailer, pull the pin on the breakaway switch (make sure the battery is fully charged) then give each one a spin (they shouldn't spin if adjusted properly). That will tell you right away what wheels/brakes are doing what and isolate the trouble to the trailer brakes or truck/controller. Need to break the issue down to smaller pieces.

[Hugo-H]

sandpaper 150-18, will it not scratch the drum or brake shoes?
How much do I have to sand it?
How does a glazed magnet looks like?
pics here of magnet and drum

[sourdough]

What does the inside face of that drum look like? The pic I'm looking at, albeit with senior eyes, looks like it is rusty and the shoes aren't hitting it?? It should be bright and shiny.

[Hugo-H]

the pic is not so good, but the drum is shiny and blinks... I have cleaned it already with brake cleaner, but the shoes looks to me to be glazed. and as chuckster57 recommended, I will sand the shoes and the drum...

[flybouy]

Originally Posted by Hugo-H

my brakes don't have enough braking power when I was at the vehicle inspection... Since my van (E350) didn't have a brake controller installed from the factory (but is pre-wired), then my question was about the possibilities and the how-to's, to determine the problem...
Secondly, my van doesn't have a tow / haul mode...and that makes driving in the mountains little bit less relaxing.. Even squeezing to 100% still does not give enough braking power...
Can it be the the brake shoes are "vitrified"? (glazing of the shoes)... but how does that look? (pic included of one of the brake shoes on my TT)
Today I will check on the current used by the magnets after pull out of the breakaway pin...

You could install a factory brake controller (if you can find one, maybe Ebay). It would require having the computer flashed to "activate" it. No tow/hual mode, mountians? I'd suggest saving up some money for a transmission rebuild, it's just a matter of when not if.

Not being a smart elic, but was this your first time at doing a brake service? Did the brake linings looked glazed before you adjusted them?

[Hugo-H]

don't think there exists a factory brake controller...my van is from 1996.
Since it is a van, there is no tow / haul mode... and it's a OBD1 ECU...
This is my first time I did a brake service... I own the TT since 2020... and we have an obligatory vehicle inspection every 2 years... When I came back from a road trip this August, I felt I had to adjust the brakes...without any dissambling at all...but due to a failed vehicle inspection, I dissambled the drums, and then I saw they looked like "glazy"...Transmission rebuild?...

[flybouy]

Originally Posted by Hugo-H

don't think there exists a factory brake controller...my van is from 1996.
Since it is a van, there is no tow / haul mode... and it's a OBD1 ECU...
This is my first time I did a brake service... I own the TT since 2020... and we have an obligatory vehicle inspection every 2 years... When I came back from a road trip this August, I felt I had to adjust the brakes...without any dissambling at all...but due to a failed vehicle inspection, I dissambled the drums, and then I saw they looked like "glazy"...Transmission rebuild?...

"Since my van (E350) didn't have a brake controller installed from the factory (but is pre-wired), then my question was about the possibilities and the how-to's, to determine the problem..." This statement lead me to believe there was a provision for a factory controller.

Without knowing if the brake lining was glazed or not before you adjusted them then we don't know the cause. Could be from overheating from hard or prolonged braking that you were trying to compensate for by adjusting them or you could have adjusted them too tightly causing them to drag.

Roughing up the surfaces will help as long as the shoes aren't heat checked (cracked) or the drums aren't discolored from excessive heat. Adjust shoes until you can not turn the wheel by hand then loosen so that you can turn the wheel with one hand and a slight scrapping noise can be heard.

The transmission will fail prematurely the when pulling a trailer in mountainous terrain on a regular basis if the drive train is is not set up for towing. The tow/ hual function reprograms the transmission shift points to help prevent overheating the transmission oil and to keep the engine rpms in the "power band" longer. Vehicles if equipped with a tow package typically have a higher capacity transmission oil cooler as well. It's high oil temperatures that damage an automatic transmission. Friction from the clutches slipping when pulling a heavy load from a stop and from constant shifting ( commonly referred to as searching) will cause rapid heat build up.

[Hugo-H]

I clean and sanded the brake shoes and the drum inside...
I measured the current taken by the magnets, and on the front axle, each magnet draws 2.8 A, on the rear axle each magnet draws almost 2.5 A each...
How about these measurements... they are ok?

[chuckster57]

Did you pull the break away pin? Plugged into shore power?

[Hugo-H]

Have pulled the break away pin to test it... not plugged into shore power...

[chuckster57]

Originally Posted by Hugo-H

Havr pulled the break away pin... not plugged into shore power...

Ok. The readings seem to me a tad low, how is the battery voltage? Try plugging into shore power and test again.

[Hugo-H]

batt voltage stays on 12.70 V... what is a "tad low"?

[Hugo-H]

with shore power, I get 3 A each magnet

[chuckster57]

You have 4 magnets. Average is 3-4 amps for a total of 12-16 amps.

Yours added up to 10.6 amps. I’m not an expert in brake electrics, but you might want to inspect all the connections.