Team-BHP (https://www.team-bhp.com/forum/)

-   Technical Stuff (https://www.team-bhp.com/forum/technical-stuff/)

-   -   Brakes Catch Fire / Brake Bed in procedure / Brake Shudder : Solved (https://www.team-bhp.com/forum/technical-stuff/54214-brakes-catch-fire-brake-bed-procedure-brake-shudder-solved.html)

This is going to be a long one.

Mods - I have searched for a similar thread, but if I have missed out please merge this thread with the same.

So I bought a 2003 Honda Accord 2.3 VTi - L AT a month back.
Beautiful car, smooth ride, sweet power.

Took it for a few speed runs on the expressway touched 190kmph and was quite happy with the handling considering I have only driven german cars till now ( read Opel Astras). Why i switched to Japs is a story for another thread.

My only problem was that the brakes would shudder when applied above 100.
It was a pulsating feel with the pedal vibrating, the car was not vibrating at all, only the brakes. Although braking fine the shudder was not confidence inspiring at high speeds at all.

Researched the subject online and the first hits scared me into thinking my rotors would need to be replaced. Further research yielded the fact that it's nothing but uneven deposits of brake pad material on the brake discs causing the brake pedal to shudder.

Solution 1: If it's not really bad it can be cleared with a 4-5 consecutive braking from 100 kmph to 15 kmph. Each progressive stop being harder. As soon as you slow down accelerate again to 100 and then brake to 15 -20 kmph .Make sure you don't stop just slow down without kicking in the ABS. The idea is to get the brake pad and brake disc to high enough temperature to get an even layer of brake pad material deposit on the discs. If you stop during this process you may leave an imprint of your brake pads thus negating your efforts. After this either drive around above 60 for 20 minutes without applying the brakes unless an emergency, or stop the car and let it cool for 20 minutes. Make sure the parking brake is not applied at this moment, try to keep the car on a flat surface so it doesn't roll witout the brakes. Repeat process. After doing this twice and the car has brakes have been cooled your problem should be gone, if not read on.

The above solution didnt work for me to my satisfaction. It reduced the shudder, but it was still there.

Solution 2: If the brake discs still have enough depth get them cut / lathe if not get a new set and get a new set of brake pads.
IMPORTANT: After the above it is very important to do a proper break in / bed in to ensure your problem doesn't come back. You have to layer your brake discs with the new brake pad material evenly to make sure the problem doesnt resurface. The bed in must be done after you have driven your car 250 - 300 km because the brake pads have protective resins which need to be burnt off to expose the brake pad material. One must drive carefully during this period as braking is less effective and also avoid hard braking to ensure an imprint is not left on the discs. Brake bed in is same as solution one but instead of 4-5 times do it 6-7 times.

Would suggest to read Brake Bed in / break in procedueres online for much detailed and accurate method.

This worked perfectly for me and there is no shudder at any speed be it 160 or 100.

Now the interesting part:

I got my discs cut and new brake pads a couple of days before my Goa road trip so I decided I'll bed them in once I cross 250 km. I had covered nearly 300 km when I got a nice open stretch of road with relatively no traffic. Braked the car steadily from 100 to 15 kmph and accelerated again, by the 3-4 braking I could feel a fade in my pedal. By the 6th braking it was the same brake fade so thought I'll make sure this problem doesnt repeat again and just to be sure will make it 10 stops. BIG MISTAKE. After the seventh braking, under acceleration I notice a lot of smoke in the area where I had slowed down, same under 8th braking. I thought maybe the engine throws smoke under heavy acceleration and I might have not noticed it earlier, this being a second hand car. Saw the same smoke after 9th and 10th braking.

After 200 metres I saw a dhaba on the highway and pulled it to let the car cool and get some tea. And all hell breaks loose. There is immense amount of smoke from all four wheels, the front two emiting twice the amount of smoke than the rear, I think to myself alright so you destroyed the first Jap car you bought. We all jump out and the check out the source of the smoke. The front brake discs are RED HOT :Shockked: like molten metal and the left hand side brake caliper has a few flames which we blow on to put out. In the meantime a couple of patrons of the Dhaba jump up to put out the fire and get a jug of water, with screams of " AAG AAG" they are about to douse the the wheels with tons of water, luckily I just stopped them in time. I convince them that its a problem with the brakes and there is no fire and we don't need the water they are quite suspicous but cool off and stand back. I wasn't sure if I did the right thing but I just knew the molten metal and cool water is NOT GOOD for my brake discs, I am sure they would have just broken in peices. In the meantime the smoke has reduced in the front and completely stopped in the back. The tires are slightly warm but the alloys are HOT!!! hotter than boiling water. You just cannot touch them. The brake discs are not red anymore.

After about 5 minutes of stopping the smoke is still emitting from the front but barely there. I hook the laptop up and google " NEW BRAKES SMOKING". There were quite a few hits and it turns out it's normal with new brakes especially if applied hard some times the resin catches fire, the advise was to let it cool down and it should be fine. A quick call to my mechanic ( not A.S.S.) reconfirmed the same.

We wait 45 minutes to let the brakes cool down completely, after that very very apprehensively took it back on the highway, first applied them slowly at 60kmph - fine. Braked at 80 kmph - fine. Braked at 100 kmph - fine. Braked at 120 - PERFECT!!! with no shudder. As my friends were really scared of another fire break out we didnt bother with the second break in run and just drove down to Goa.

The car has been driven 2000 kms since the fire and I must say the new brakes are sweet just sweet!! A couple of ghats with all the twists and turns really made use of them and boy was it fun throwing the Accord around.

So for the break in would advise only 6-7 stops or have a fire extenguisher handy lol:

P.S. I sure needed more smileys, but Rules, Rules, Rules.

Hi Indian,

Initially before the discs were refaced/replaced (pl clarify what exactly was done) there was a condition called warping of the discs, (the disc deshapes from being a perfectly flat surface to being slightly wavy, this happens sometimes due to heat/pressure/stress during braking.


As for fire/smoke, I really do not know the reason for the Brake drums (rear - i am assuming you have drums at the rear and not discs) though its highly unusual for an ABS equipped car to have drums at the rear.

Why they smoked ? - reason is very simple, new replacement pads might have been of a material having a higher wear rate. (this is common with non authorised service stations)
Now new pads have some additional material to cope with the running in of new pads.

When you ran your car at speed the new pads obviously have continously rubbed against your discs, the heat build up was due to this. You were lucky your brake fluid did not boil and cause complete lack of braking.

If you can put up pictures of the discs/pads (without the wheels on the hub). We could get a better idea. Also do let us know whether the pads are OEM or replacement.

I have had similar experiences with other cars.

Cheers.
MM

There are plenty of cars with rear drum brakes and ABS. Swift is an example.

Rotors getting red hot and the pads catching fire isn't anything bad either. When you brake, the kinetic energy is turned into heat. That heat has to go somewhere.

The Accord has discs all around.

It is not necessary that a car with drums on the rear has ABS working on those wheels. Many budget cars have single channel ABS that only works on the front wheels. Rear wheel lock up is precluded with correct brake bias settings.

The primary purpose of ABS is to allow steerage under hard braking by preventing wheel lock. That makes it mandatory only for the front wheels!

Hahaha... that was surely a "hot" moment! Good to know that it turned out great.

Safe motoring, Indian1979.

Wow stopping 10 times is excessive for just a simple brake bedding. I usually stop at 4 for a street car and 6 for a high performance car.

The brakes are simply not built for that kind of torture and you plain and simple overstepped their boundaries. At least you know that your brake fluid is in good shape haha.

But why did you want to try out something, when you are out for a long distance trip ? Not a good idea, unless you have a spare set of everything in case something went wrong.

This is a very good and informative write up. I just put in brake pads and should bed them in soon.

i think there has beene excessive friction between the pads and the discs. i think the brake pad material is non-confirming or the disk that have been cut are not done properly.
mainly you have been very harsh on the brakes continously and havent allowed the brakes to cool before next harsh braking. i ideal conditions this type of braking doesnt occur

@thread starter: I would recommend you have experienced, knowledgeable check and give you solutions for car problems rather than you just researching everything online and coming up with your own solution.

Breaking in pads is absolutely needed if you're gonna use new pads on non-skimmed discs. Some aftermarket pads come with breaking in coating to help speed up the process.
For new pads with skimmed/new discs, you just have to use them moderately for a few kms or 100 kms depending on the pads.You don't HAVE to focus on bedding them.

That said, Breaking in a set of new brake pads is not rocket science. You have to know precisely how much pedal effort you need to give it, at what speed, at what intervals.
In your case, (while you didn't need a special break-in ) you overdid it!

But, thanks for posting this so others can learn from your experience. :)
:Shockked:
It maybe normal.But,it IS bad!

I completely agree I really overdid it.

LOL man, that is one truly unique experience. I guess its an eye-opener for us in telling us what NOT to do. This is the first time that I am hearing a first-hand user account of burning brakes on an Indian car. I'm glad though, that you guys got away without any significant damage.

One heck of a thread!

Smokkkkkkin'




I'm not sure how much of your first 250-300 kms you drove on the highway, but generally if youre doing a lot of mile-munching on the highway, it is best to increase that 300km limit a little, since you probably aren't doing enough braking on the highway. 300km in stop and go traffic is best.

I dont think there are any "protective resins" but rather resins that were used in the manufacturing / moulding process.
When new brakepads are heated up beyond a certain temperature these resins release gasses, which cause something called green-fade.

The running-in procedure for brakes generally involves burning/wearing out these resins gradually (without the green fade caused at higher temperatures).


Indeed!!! Big mistake!
When you feel brake fade, braking more (more heat) is not going to help at all.

Brake fade here could also be caused by the pads getting heated up to a point where the coefficient of friction greatly reduces, or alternatively, the brake fluid could be starting to boil (spongy pedal), or even both.


Definitely did the right thing here!! Good save.


A "breaking in coating" ? I've never heard of this (atleast not by this name) and i think it is untrue.
What the brakes go through during initial use is purely an unfortunate bi-product of the manufacturing process IMO.

cya
R

even better
Picture Of The Day: Ferrari FXX Under Some Seriously Hard Braking
:)

Same thing happened to me in my Accord. We were ripping around at high speeds (150+) around an empty road and when we stopped, there was that foul smell from the tires. We got out and saw that the wheels (all four of them) were orange-red, and we weren't really sure what to do. Luckily, we didn't notice any flame. We just sat by the side and after a while they became normal.

It's happened about 10-15 times since that day. :D