Brakes WTF! help please .

[Shayne]

After fitting rebuilt calipers , new discs all round and handbrake shoes i finally got to take it for a run .

When i got home or at least into the lane behind my house (locking my other truck in) she stopped dead . ok me thinks i half expected this from the handbrake .

Long story short it was the front passenger caliper ?

The genuine mrT pads were glued to the disc . I need this fixed now but all i can do is put the pads back in which lends no confidence .

I would appreciate any suggestions with regards to what caused this ?

 

[Pumpy]

what causes it? heat. maybe driving too hard on brakes that havn't been bedded in?

Toyota wil have a bedding in procedure written down somewhere, not that I've seen it, here's a link to some other makes recomendations... http://www.tirerack.com/brakes/tech/techpage.jsp?techid=85

found this from StopTech

NOTE: BEFORE COMPLETING THE BREAK-IN, DO NOT COME TO A COMPLETE STOP WHILE THE PADS AND ROTORS ARE VERY HOT! THIS WILL TRANSFFER PAD MATERIAL NON-UNIFORMLY ONTO THE ROTOR, CAUSING A VIBRATION DURING FUTURE USE.

from their bedding in procedure...
http://www.stoptech.com/technical-s...s/stoptech-sport-brake-pad-bed-in-suggestions

Probaly best to clean the pad material off the disc and then go a bit easier/bed them in
HTH

 

[Sag]

Wow Shayne,looks to me like they have been cooked buddy,did you rub the pad down abit first?cleaned the oil off the discs what they come with to protect them while on the shelves buddy? Other thing is we're they free in the holder mate?hope you get it sorted after all the hard work mate.

 

[Shayne]

Half hour gentle driving in heavy rain with one hand on the handbrake just in case . I am only a learner when it comes to car mechanics remember .

It's all gone back together after scraping the disc clean and sanding the pads and its parked up tidy so the immediate problem is sorted but i would still like an answer .

Best i can come up with is air in the line at the caliper so it wasn't backing off and when stopped with a hot disc the paint melted to the pad - does that sound feasible ?

 

[Shayne]

Degreased the discs when they came out of the box Sag new slide pins and red rubber grease at edges of pad . I didn't sand the pads i washed them with brake cleaner .

 

[Shayne]

Found this

1. From 60mph, gently apply the brakes a couple of times to bring them up to operating temperature. This prevents you from thermally shocking the rotors and pads in the next steps.
   
   
2. Make eight to ten near-stops from 60mph to about 20 mph. Do it HARD by pressing the brakes firmly, but do not lock the wheels or engage ABS. At the end of each slowdown, immediately accelerate back to 60mph, then apply the brakes again. DO NOT COME TO A COMPLETE STOP! If you stop completely, with your foot on the brake pedal, pad material will be imprinted onto the hot rotors, which could lead to vibration and uneven braking.
   
   
3. The brakes may begin to fade after the 7th or 8th near-stop. This fade will stabilize, but not completely go away until the brakes have fully cooled. A strong smell from the brakes, and even some smoke, is normal.
   
   
4. After the last near-stop, accelerate back up to speed and cruise for a few minutes, using the brakes as little as possible to allow them to cool down. Try not to become trapped in traffic or come to a complete stop while the brakes are still hot.

So too short a run might well be the answer .

 

[Towpack]

In the 35+ years I've been driving and tinkering with vehicles of various descriptions I've never read or heard anything as extreme as that for bedding in new discs & pads. I've always been led to believe you just drive as near to normal as possible while at the same time being mindful of the fact that the brakes may not offer full performance until fully bedded but nothing about overheating or melting pads! I fitted new front discs & pads last year and never really gave much of a thought to be honest as they felt good from the very first mile. The above procedure reads similar to that for bedding in new 80 series handbrake shoes.

 

[Shayne]

I live in town and hadn't realized it was 5pm when i went out so i probably did more braking than driving , only incredible luck got me home without stopping . Me and the mrs are sitting here trying to think of somewhere other than a motorway that will let me drive for more than a couple of minutes without having to stop .

 

[Shayne]

Just done 10 or 15 miles proper driving with little traffic about and all is good so it was my fault i think too keen to put some wear on them without giving any thought to letting them cool . A lesson learned .

 

[Sag]

hope there ok now buddy,just take it easy with them for a bit,another thing is did they slide in the pad holder ok,it's just I always take the paint off the top and bottom of the pad then put copper grease on the top and bottom so they can't stick in there if you know what I mean.

 

[clivehorridge]

It sounds as though what you experienced was at the extreme end of the cautionary warning Shayne, so probably just bad luck and Sod's law that it should happen to you.

I've always taken it easy after having new pads fitted, the brakes never work well straight off, so gentle braking and leaving extra space behind the car in front was always my ploy.

I must admit, after having new discs and pads fitted a few k ago, the fitter did warn me not to get the rotors too hot in the early days, because some customers have warped their new discs, being over enthusiastic too soon.

Hope all is well now mate.

 

[Shayne]

Just driven it to Cardiff no problems at all and i'm sure the garage that are fitting the stainless brake lines for me will notice if anythings amiss .

 

[SafariTecPeter]

End good-> All good?

I do too only wash the new discs & throw them on with new pads. Yesterday infact.
Abit of smooth carefull breaking & all should be OK
The possible air in the brake line should be irrelavant to the caliper releasing when depressing the break pedal.

 

[Sag]

Glad all ok Shayne

 

[Shayne]

Thanks Sag at least it might save someone else making the same mistake . I don't collect the truck until tomorrow so i won't count my blessings just yet but i feel it will be ok .

 

[Sag]

I would of thought it will be fine buddy,if anything you might of cooked your pads and caused them to crack but doubt it.

 

[froggy Steve]

my calipers are as rusty as fu..anything. The man wot does had to file the rust off, just to get the new Yota pads and discs to stop binding! He made new pins as well.

 

[frank rabbets]

Shayne you've been amazingly unlucky to have suffered this. Discs came out in 50's and I've worked on them since then and have never seen nor heard of this. I just drive off after making sure the brakes work and then get a feel of how they perform and drive accordingly. They can fade easily though especially if you put new pads on a rutted disc.

I guess the new pad may stick to the disc more easily than when a glaze has formed on it after some use. Air in the system would be irrelevant. There is no pressure in the system with your foot off the brake pedal as the system is vented through the master cylinder to atmospheric pressure.

Did you check that the wheels span freely after fitting?

 

[Shayne]

Yes Frank all 4 were spinning free i reckon it was just a fluke of circumstance , i came home down hill and the last corner into my back lane is a long 180 degree turn , i'm guessing i was on the brakes for it and came to a full stop with just enough surface heat to bind the pad to the disc doing the most braking . It looks cooked but penetrated the pad 2mm at most . Garage just phoned "all done come and collect"

 

[Pumpy]

Result! nice one Shayne