Hi, I have hot front lugs and rims(Scalding not smoking) and cant figure it out. I have done the following:
Changed the flex hose on both front L & R.
Replaced rotors front L & R.
Replaced pads and hardware front L & R.
Bled the braking sytem from rear to front carefully.
There are no leaks at master cylinder, there is no bearing groaning sound on either sides.
Im assuming this is either sticking front calipers or some other hydralic issue keeping the pads too close to the rotors.
Please advise!
This vehicle is a Toyota Corolla LE 2017. 103,000Miles
If the pads aren't dragging on the disc, the wheel bearings could be locking up causing the friction.
Doubtful. There is no noise coming from either bearing in front. And, as with the calipers, BOTH at once seems unlikely with no noise.
They don't necessarily have to be making noise to be bad.
I should have replied more clearly. The brakes are definitely dragging on the discs. I pulled the tires again and there is zero play between the pads and rotors. The caliper piston is not retracted at all. The brake system is keeping constant pressure on the pads but not enough to completely bind the wheel.
Most likely your caliber is bad. When they stick the breaks will heat up and be red hot compared to other wheels. There is a slim possibility that the slide pins are also sticking.
Yes, slim possibilty for the sliders, as I have pulled them and cleaned (no rust) relubed them well. The boots were not torn and I suspect the sliders are ok.
The one thing out of the ordinary that I have noticed is an occasional slight drop in the brake pedal of about a quarter inch on braking. This is only occasional and very slight. No going to the floor by any means, I assume it's a change in vacuum somewhere though. Perhaps my brake master is leaking internally? I am going to replace the calipers tomorrow with rebuilt, so if that doesnt remedy the sticking then I guess I should assume the master is to blame.
I am going to replace the calipers tomorrow with rebuilt
Wait, are both front wheels getting abnormally hot? It’s odd for both the 5 yr old callipers to go bad together..
Yes, they are. I feel the same way, yet I can't seem to rule out the calipers. I'll go ahead and change them, bleed the system and see. If this fails I will assume it must be the brake master. I welcome any thoughts.
When you did the brake job, did you squeeze in the calliper pistons, before you installed the new pads? If not, that’s your culprit right there.
I did squeeze the pistons at that time however, I did not check that the fluid reservoir was above max. A week ago, after watching a YouTuber giving advice on this, I recompressed both again and turkey basted out the excess. I left the resorvior just above the midway point between max and min. No effect.
I changed both front calipers yesterday with good rebuilt units; gravity bled the new calipers then did a standard bleed. The car took off great with no sticking but by the time 10 or 15 minutes elapsed it was back to the same state. Too much pressure being exerted on the front caliper pistons.
Someone suggested loosening the brake master cylinder nuts about 4 turns to see if that would effect but it did not. I assume this is an internal problem in the brake master. I've considered pulling the ABS fuses just to rule that out but im a little apprehensive about messing with ABS.
If you didn’t use a scan tool to bleed ABS brakes, then as @doc mentioned, you could’ve got air in the ABS module.
Did you have the proper scan tool hooked up to set the ABS solenoids when you bled the brakes?
No. I was not aware that would be necessary. Please elaborate.
Thanks @chucktobias.
You're welcome @doc - that looked like a pretty good overview. It's actually not something I've had to deal with myself, I've had no problem bleeding my ABS-equipped cars the old-fashioned way. However I've never had air in the ABS unit itself to deal with.
Yeah, what happened to the good old pre-ABS days when you got your old lady to pump and hold - the brakes that is? @chucktobias
Thank you all for the very insightful responses. I have now ordered a tool to do the ABS bleed assist. I will do that this Wednesday, but I suspect I will have to change the brake master. But cheers to hoping!
doc 
Thanks @mmj