recurring brake rotor problem...

s1ngletracker · 11-15-2009

So I've been having a rather frustrating problem with my rotors causing brake pedal vibration. About 3 weeks ago I got brand new Napa premium rotors, and i'm already getting pulsation. Extremely frustrating.

I'm wondering if there's something about my install/bed in procedure that's causing it... or if I'm just having bad luck.

First question, do I absolutely need to get new pads every time I get new rotors? Or can new rotors be used with older pads with plenty of life left in them?

My process for installing new rotors:
1. clean new rotors with brake cleaner
2. Unbolt caliper and remove old rotor
3. wire brush axle flange/hub mounting surface to make sure its clean
4. Take pads off caliper, lubricate caliper slider and where the pad contacts the caliper (not sure what this channel thing is called)
5. Install rotor and caliper
6. Wire brush mounting flange of the wheel to make sure it is clean and free of debris
7. Install wheel and torque evenly to 85 ft lbs
8. Bed in brake pads to rotors using a 10-12 'firm' stops, increasing in speed, never coming to a complete stop.

Am I doing something terribly wrong? Am I missing something? I'm getting really frustrated with having to buy new rotors, and I hate brake pedal pulsation.

Kracka, Mustgofaster, I'm sure you guys have some insight on this.

**4seasons69** · 11-15-2009

thats a pretty good procedure. how much rust is on the hub? if there is too much it can cause a pulsation. sometimes a wire brush isn't enough and you need to use a 90 degree die grinder and a green 3m roloc disk to get all the rust off.

**Kracka** · 11-15-2009

Your procedure sounds good. My guess is the pulsating is from pad transfer of some sort, which is slightly odd since you're using new rotors though (perfectly fine to reuse pads with new rotors, I am on my Evo). My suggestion is to remove the rotors and sand them by hand with some 120-grit until the surface looks shiny again. Try to do this evenly across all friction surfaces of the rotor. Also use the 120-grit to take a small layer off the face of the brake pads. This will give everything a virgin surface for bedding together.

Follow these bed-in procedures:
http://www.racingbrake.com/v/main/te...in%20procedure

s1ngletracker · 11-15-2009

Alright, I'm gonna give it another try, but I may get new pads as well. I have no idea what kind of pads they are, some sort of ceramic, they came on the car. I just don't have any faith in them.

Any suggestions for a good street pad? I want something that doesn't have to warm up to be effective.

**Kracka** · 11-15-2009

Ceramics are a pretty good general street pad; I don't think its them causing your problem. Give my suggestions a try before throwing more money blindly at the problem. If you insist on getting new pads though list up how you use your car and what traits you're looking for in a pad and we can give some guidance.

s1ngletracker · 11-15-2009

Those bed in procedures are basically what I've been doing...not exactly but very close. I just don't want to go for reproducing the definition of insanity here.

The most glaring thing about how that procedure differs from mine, is they say don't get below 25 MPH, which I probably had done when doing my bed-in with the most recent new rotors. Maybe that would make the difference?

sleepydsm · 11-15-2009

Ok how are you feeling the pulsation? Is it in the pedal, or on the steering wheel?

Rear brake pulsation usually is felt in the pedal, while front is felt in the steering wheel. It is typically amplified as speed increases.

sleepydsm · 11-15-2009

Quote:

Originally Posted by sleepydsm

Ok how are you feeling the pulsation? Is it in the pedal, or on the steering wheel?

Rear brake pulsation usually is felt in the pedal, while front is felt in the steering wheel. It is typically amplified as speed increases.

I will assume you are talking about the front. Are you sure the steering and suspension components are good? IE Wheel bearings, tie rods, ball joints?

s1ngletracker · 11-15-2009

its the fronts. Wheel bearings, ball joints have about ~10k miles on them, as does one of the tie rod ends, the other one is fine.

Spikesoftail · 11-15-2009

With a brand new brake rotor, there should be no shake at all. Is this shake starting immediatly after the install, or is it happening after a few day/weeks/months of driving?

If its happening immediatly I would have to say its something about the install. Rotor not seated on the hub properly would be my first thought.

If its happening after a bit of driving I would say your either really hard on your brakes ( I know that never happens) your rear brakes arent working properly causing your fronts to do all the stopping, or your calipers arent releasing. All of which would cause your rotors to heat up and warp pretty quick.

s1ngletracker · 11-16-2009

well it started soon after (a week or so?) with only a very, very slight, hardly noticeable pulsation. It is just progressively getting worse.

joesushi · 12-15-2009

Replacement rotors these days are almost always low quality metal. Buy Brembo blank oem replacement.

Pushit2.0 · 12-15-2009

Have you lubricated the caliper slides at all? If you have break issues the only step you missed was a set of pads, yes it sucks your old ones have life left but if you want the breaking issue gone you must start new.

~John

**Kracka** · 12-15-2009

Quote:

Originally Posted by joesushi

Replacement rotors these days are almost always low quality metal. Buy Brembo blank oem replacement.

Centric 120's are very good rotors. These are the blank cores that Stoptech and Powerslot use. Some RotorPro sets also use these. Other RotorPro sets (seems random, no way to actually tell) use the Centric 121 cores which are your typical replacement Chinese junk; they're also sold under the C-Tek name. A few batches of Powerslots went out using these cores a while back, but now they're using only the 120's.

s1ngletracker · 12-15-2009

good info kracka.

John - I'm thinking i'll be going in that direction the next time this happens. Things seem to be holding steady, maybe the cold has something to do with it. Early this spring for sure, I might just put down some cash on rebuilt calipers all around, new rotors, and some nice pads and start from scratch. I'm guessing there might be issues with my current stuff that I'm unaware of.

joseph sushi - I'm either gonna go with those or with some frozen rotors, as people say they stand up very well to warping.

nonetheless, i'm definitely not throwing another set of rotors at this setup without at least also changing pads. I just think they kinda suck for creating even pad transfer, and might not stand up to heat very well.

**Kracka** · 12-15-2009

Frozen Rotors are another that use the Centric 120 blanks. Beginning to see a pattern here?

s1ngletracker · 12-15-2009

so kracka, whats the best way to make sure what i'm odering is the Centric 120 blanks? Are those also what brembo uses, or do they have their own design altogether?

**Kracka** · 12-15-2009

I believe Brembo has their own made. The easiest way to make sure you're getting the Centric 120's is to just order them specifically. I just looked up your options and the Brembo blanks are slightly cheaper than the Centric 120 blanks. Both are good choices, but the Centrics do include a black electro-coating which will keep them looking nicer for longer if you care about that.

s1ngletracker · 12-16-2009

well, looks like I know what i'm getting for my next set of rotors

**Kracka** · 12-16-2009

If you're referring to the Centric 120's with black e-coating you'll be very happy with them. I have a set on my Evo and they bed-in very nicely, seem to be wearing perfectly, and the coating still looks good. I got them from MAP. The guys who regularly track their cars report the Centric 120's being more durable than the stock Brembo rotors.