Brakes getting weaker?

[J3110]

Just ran my truck and noticed that the brakes seemed a bit soft and I don't know why(yet).

Little history:
Running a MM/7XL(feigao) with 4s lipo in an E-Maxx.
All MM settings are at their lowest(to keep heat in check) with braking at 30%.

The can has been popped and the rotor spun a few revs while the can was popped(see the end of this video).
JB Welded the can back together and all seemed to be fine...until
...I was running at the beach one day when the truck just stopped and the ESC kept switching off anf then back on...off...on.

I redid the battery harness and also added a Novak 24v capacitor to the + and - ESC leads.

Tested it out and it seemed to be working fine.
Today was the next time I drove it and as time went on, the brakes seemed to fade.
They are weakest when going from throttle to brake immediately and are a little better of I pause between trottle and brake input.

Motor was about 150, ESC was around 110 and batteries were barely warm.

I've read some of the debate around the capacitors and weather or not they do anything. Mine gets fairly warm, so I know it's doing SOMETHING, but can't really tell much of a difference. I just was hoping to mitigate some of the excessive heat from the 7XL as one of the mentioned effects of capacitors.
I am also wondering if maybe the capacitor is what is causing the brakes to fade like this.

I'll try bumping up the brake power to see if that helps.
Thoughts?

[brushlessboy16]

are you sure you have the polarities of the capacitor leads right? the striped side is negative :D

[J3110]

Originally Posted by brushlessboy16

are you sure you have the polarities of the capacitor leads right? the striped side is negative :D

Fairly sure.
Red to red, black to black(cap had wires on it already).
I doubt cap polarity being mixxed up would have this kind of effect, though.

[brushlessboy16]

oh alrighty, umm check all the leads to and from the esc for loose or broken connections

[J3110]

The power's not cutting out or anything, so I doubt it's a short or broken connection.
I tried raising the brake power to 50% with no real effect.
Raised the motor start power from low to medium and then brake power to 80% and it seems to be stopping like it used to at 40%.
I guess the motor's just starting to go. Either that or the speed controller.

[tc3_racer_001]

could the motor have heated up too much some time?

ive noticed that if you demag a motor u get way less brakes... but your temps seem ok?

also, double check your radio... i felt so stupid after i realised why my brakes were not working

[J3110]

Yeah, I think I mighta demagged the rotor.

Awhile back, I "popped the can" and the rotor spun a few revs while the can was open and the rotor shaft was at a slight angle, so I am thinking this may have damaged the front bearing or the rotor/coils themselves somehow.

After running it tonight, the brakes faded and are like they were before I boosted the braking force again. I also noticed that while temps were fine for the most part, the rotor seemed much hotter than any other part of the motor. While I'd think this is typical as that would be where the heat would logically be highest, it is my only explanation.

Prior to this condition starting, I redid the battery harness and added a capacitor to the power leads going to the MM, so really the cap is the only other thing that may be any different.

The brakes faded rather suddenly and at the same time, I noticed way more cogging at lower throttle positions than is typical.

Seems almost like I heated the rotor up to a certain temp and once it crossed that threshold, the magnets just kinda went. Still works, just not nearly as well.

The only other thing I could imagine it being would be the cap or the ESC if it is starting to die on me.