Brake pads/ rotors warping

Im having issues with my passenger side brakes dragging its intermittent doesnt happen all the time but is very noticeable mainly at highway speeds pulls to the right and not sure why this is happening has been an on going issue for a while now trying to track down the reason why…

My truck is an offroad and has the electronic brake master cylinder ABS TRAC W/VSC

All parts were replaced/ serviced within the last 10k miles
New brake calipers, rotors, and pads stoptech brand
New extended stainless brake lines from wheelers
Rear drums, shoes and brake cylinders all replaced with new hardware.
Can guarantee the brake system is all new fluid from how many times Ive bleed the brakes following service manual to include bleeding brakes using tech stream as well…

So two days ago the dragging got even worse noticed it after replacing cvshafts boots that driving less then 10 miles you could smell the brakes getting hot temps of 300deg using IR temp gun.

That night I pulled calipers checked for stuck piston they all seemed to move fairly easy, But had some other caliper laying around so installed them bleed system and put new pads on both front wheels. Tires spin freely again

Truck seems to have much better coasting and acceleration now but yesterday and today driving home from work 11 miles get home shoot rotors with temp
Gun and getting 230-250 range only in one spot on the rotor rest of the rotor is 130/160 range so jack up truck spin wheels and they spin perfectly fine…

Anyone else have any ideas on what might be happening????

also attached picture of brake pads and does anyone know why the pistons melted the shim never seen anything like that before??

Hope this all makes some type of sense and not all over the place Thanks in Advance

 

I've seen wheel bearings cause this. Sometimes hard to detect but the slight play causes the wheel to cock and cause higher drag on the brake system.

IR guns can sometimes pickup wheel bearing heat, try to shoot behind where the cv axle meets the knuckle and compare side to side.

Rotational noise while driving, and play while shaking the wheel is the other way to detect, but usually Tacoma doesn't have play, just noise.

 

Forgot to mention the front Hubs are new as well they were purchased from this forum cant remeber the OP name but he sells them and are just as good as oem…. When shooting temps behind wheel near cv axle temps are below 120deg front axle housing 108deg so wheel bearings check out good.

There is very minimal side to side play coming from my intermediate shaft and i mean very minimal play….

 

Next question, do you have the spring that sits between the pads installed?

This could be a sticking master, typically unlikely. You may at the very least check free play. Which is a massive pain in the ass.

If the vacuum booster nub is contacting the master cylinder without any free play it causes drag.

Also, check to see if your brake pedal has free play, it should have 1/4"-1/2" of movement in wiggle room.

 

caliper getting hung up and not sliding on the pins?

 

The spring is installed even tried adding a second one to the top didnt notice any change.. When i have someone press the brakes while watching the pads you can see them tighten and free up.

My truck doesnt have a vaccuum booster its all electronic using solenoids…

And will have to check free play cant remember off top of my head how much I had before…

 

My caliper is not free floating the pads slide on the pins and which the pins are clean and pads seem to slide easily unless they randomly get hung up at times

 

"New calipers" are they new or rebuilts as I would still think a hanging up caliper.
Lots of the rebuilt ones are not very dependable (not cleaned well internally and reassembled by who knows) as they do large lots of them and low budget operation.
There is a fluid passage between the 2 half's of the caliper with 2 pistons in each half. Appears your pads are not wearing equally on both sides of the rotor by the pic.
Also, you said the pads are sliding on clean pins so pad to caliper body clearance should be OK (no painted over crap in the way) as sometimes pads "stick" due to that.
You put new flex lines on too so that takes a crappy/plugged/restricted line out of the question.
I attached a link to pics of what the caliper internals and seals look like.
2 Gen Caliper Rebuild | Tacoma World

 

Agreed - "new" parts (actually new or rebuilt) CAN be faulty - especially these days. It's POSSIBLE the "new" caliper is not working correctly in real-time. From the looks of the pads, it doesn't seem like one of the pistons (out of two on each side) is getting hung up, which makes me think the pressure (at the caliper) isn't relaxing after you release the brake pedal.

It SEEMS (to me) it may be an internal problem in the caliper not releasing the pressure - which is also indicated by the fact that it no longer happened when you swapped out older calipers.

 

My 2011 did the same things with replacement pads. The steel edge of the pads rusted I had a hell of a time just getting them out they were bound on the edges of the pad still had plenty of pad just a shity pedel. I went after the caliper removing rust where the pads fit into the caliper the rust was from the pads not the caliper. New set of different brand pads no problems since.

 

cant remember if they were new or reman know they were purchased from rock auto and not the cheap ones but Ill have to take it apart and inspect just odd to me this isnt the first time it has happened seems to happen about every 10k miles or so got the old ones back on can still smell the brakes getting hot with them sonthere is something else still wrong or something

 

i agree with you that the pads are uneven and wearing different the outside pad is the one that is wearing kore then the other

 

Look for uneven pad wear. Inboard pad vs outboard and also side to side of the vehicle. That may help narrow down which caliper (or pad) is sticking

Pull the pads out and look at the caliper where the pad end butts up against it. Look to see if the pad has worn a channel or groove in the caliper

 

So here's my newest theory. That's one good thing about theories - you can make up all kinds of stuff.

Anyway,

1. The pads are not wearing unevenly (side to side - slight inside/outside differences is common because of how calipers move/applies pressure).
2. The fact that it's not uneven side to side, indicates it's likely NOT a situation where a piston is getting hung up.
3. I would think it would be fairly rare for both pistons in a two piston caliper to get hung up at the same time
4. You seem to indicate that it has occurred with multiple calipers(?)

Based on #4, it rules out a problem with the specifically new caliper, which now lead me to think it's some kind of problem further up the chain, and reinforces (in my head at least) that it's a pressure problem (ie. pressure not being released/completely released when you release the brake pedal).

The odds of it being something in the line is low (unless there's a kink or something along the way).

MAYBE it's a problem with the something in the ABS system, like a valve in hydraulic unit not operating correctly, so it's allowing easy flow in one direction, but resisting flow in the other (when not actively controlling the ABS).

Of course, I wouldn't just swap the hydraulic control out - it's expensive and a PIA, but just pointing to something that it COULD be.

 

As long as I have been trying to figure out what it is your theory is exactly my theory either its an ABS issue or one of the solenoids is acting up in the master cylinder which I think is more likely since its intermittent and solenoids are known for being hit or miss and very hard to diagnose sometimes
Was hoping someone else would come up with another idea since I do not want to drop 1200$ on a master cylinder and it not fix the issue…

 

If you don't have (or have access to) a bidirectional scan tool, perhaps you can try testing it "in reverse."

What I mean is drive somewhere where you can intentionally get the ABS to activate, preferably over a prolonged length.

Hit the brakes.

As the ABS pulses the brakes, if one side isn't releasing properly, you may feel a pull to one side because one side gets "stuck" at least a little, while the other side properly pulses.

 

If a solenoid was sticking the unit would likely be coding

 

That's the thing - it may be sticking/slow enough to cause a problem, but not to throw a code

 

But the solenoid would have to be stuck for a good amount of time to smoke his brakes. Like constantly stuck, driving down the road. He's saying the steering wheel pulls because its so bad. If a solenoid sticks for anything longer than a split second it will code

The problem has to be down at the wheels.

Any pinched or kinked brake lines?

 

I have techstream I know there is a way to test all the solenoids but have not done it yet