Adamrotor

I replaced my brakes with new brake pads, rotors, brake lines and flushed the brakes after. I did my brakes before and had no problem, used same pads before which are Hawk Hps pads. My first dilemma was that the rear brakes were a tight fit, they are pretty much touching the rotors. The fron rotors and pads were fine after replacement. I flushed the brakes no leaks. Test drive the car and rear rotors are rubbing to a point where the car stops on its own, and the brke paddle pretty much is going down to the floor. I am going to flush the brakes again on friday and let the car sit till then, let me know any suggestions or fixes anyone can advise.

Thanks

DeadOriginal

Wow. Thanks for this faq. This is going to come in handy.

Huey52

iTrader: (2)

If the brake pedal is going to the floor it sounds like you didn't bleed the air out of the system when you installed the new lines. Remember that hydraulic fluid can't be compressed, but air can!

A slight drag on the rotors is normal, presuming you properly retracted the caliper pistons to begin with. 'Stopping on it's own' is a bit vague, since all cars will eventually stop on their own.

justjim

It may be that you didn't screw the rear pistons in far enough to reset the automatic adjuster. Some people have commented that you have to screw it all the way in, not just enough to put the new pad in. Make sure the piston is screwed all the way in first then check the pad fit. Also make sure that if there is a pin on the back of the pad that it is in the slot on the piston. The slot should be parallel to the direction of pad insert, so the pin will slide ride in. It is easy to mess this up as it is hard to see so spend some time to make sure it aligns properly.

If your rear pads were too thick for some reason that would just aggravate the situation. You may have to shave the pads down for proper clearance.

Huey52

iTrader: (2)

Good point on the pad (shim) pins in the piston slots. See the "Rear Brake DIY" for some excellent pictures to illustrate the proper fitment.

Adamrotor

Thanks, I'll do all that and post an update. Thanks again.

longpath

iTrader: (1)

I'm a bit perplexed by some conflicting information I'm coming across elsewhere. In motorcycles, sintered brake material seems to be fine for street use; but the only definitely sintered pads for the RX-8 that I've been able to find are the ones from Project Mu, which are strictly for racing, based on their quoted temperature range. The Carbotech pads that don't use a binder appear to be a variant of sintered technology but using more pressure and less heat to form, assuming I understood their description properly (I know that's a huge "if"). I'm now debating between Project Mu Type NS, EBC Yellowstuff, possibly Cobalt XR2/XR5 (XR2 front XR5 rear), and a few others, trying to narrow my decision pool down.

I'm not really concerned about the cost of the pads; but I do want good cold bite, high torque across the thermal range, and a good high temperature ceiling. I'm looking for a pad that can be used safely for a daily driver; but could also safely endure a track day or HPDE school (and still be safe enough to drive home afterward). I also want to keep the rotor wear low. The last two qualities, if I were to put together a wish-list would be low squeal and low dust. I am willing to deal with increased cost to achieve as many of those points as I can. My RX-8 is a 2004 with roughly 45K miles and still on the original OEM pads.

I did read through this FAQ, as well as the track day brakes thread and regret I still can't piece together an answer; but I know there are people here who have more experience and knowledge than I have and I'm not going to stick my head in the sand because I'm too proud to admit I can't figure it out on my own, even after reading through the various brake threads here and elsewhere.

Race Roots

iTrader: (64)

Project Mu would be a 4-6 week wait time, last time I talked to the major US Distributors they were no longer going to be stocking Project Mu for the RX-8. Great pads none the less.

As for the EBC Yellow I have heard good and bad feedback, but none of the feedback I have received about them were from an RX-8 application.

As you can see from the these reviews very mixed feedback.

http://www.ek9.org/forum/brakes/1478...ff-review.html



As for Cobalt I will leave that to others to comment, they are great pads as well from what I hear from fellow members.


Another Pad to look at is the ET800 from Racing Brake, I have had some great feedback from people that are heavy spirited drivers as well as those that take them to the track. They have great cold bite, excellent modulation and no fade up to 1400 Deg F.

This by far is one of the most interesting reviews that I have come across from the ET800 and up series pads. Especially from a Z06 owner I was impressed.

http://forums.racingbrake.com/showthread.php?t=313


Also Hawk Hp + is favorite of mine as well I swap between these and the 800-900 series pads from AutoX to track use. I have yet to use the 900's yet but I will be posting a review after I get back from RRR.

If you decide on Racing Brake or Hawk let me know we stock all of their compounds in house even the HT-10's as well.

Hope this gives a little more insight and others can add to the cobalt feedback.

justjim

longpath I think you are overthinking the issue. A couple of points that may not have been clear in the Brake FAQ. There are street/performance pads and there are track only pads. Whether you can use a street/performance pad at the track depends on 2 things, your level of skill and the nature of the track. If you are new to tracking and/or the track is not brake intensive, you may be able to use a street/performance pad at the track. However, if you have progressed in your skill and/or the track is brake intensive you will eventually find that you will benefit from a track only pad.

Why are certain pads track only and not recommended for street use?
1. They are more expensive, this doesn't bother the rich.
2. They perform better at track temperatures, although some modern track pads perform OK at street temps and can be used to travel to the track.
3. They are harder on rotors.
4. They won't last as long as street pads.
5. They are noisier.
6. They are dustier, and some have corrosive dust.

Some people get by with lower level track pads on the street despite the above issues. Carbotech XP8s will fit this bill. Its a compromise. All performance pads will dust more than OEM. Some of the "ceramic" pads are low dust but they probably have lower thermal range than the OEM, fine for street but not the track. Ceramic is a bit of marketing hype as many of the track pads also have "ceramic" compounds in them as well. Just think low dust and high dust.

If you are relatively new to tracking and want to use the same pad on the street and track I would suggest Carbotech Bobcats or AX6s, Axxis Ultimates, or Hawk HP Plus. There are others that may fit the bill as well. Keep in mind that as you progress none of these pads will hold up to serious use on the track by a good driver.

By the way virtually all pads include a high content of some kind of powdered metal, iron, brass, aluminum or other pressed into or bound into the complex component mix. A true sintered metal pad would be essentially 100% metal such as brass. The Cobalts (not Carbotech) press theirs rather than use binders but that mostly relates to bedding procedures.

longpath

iTrader: (1)

Thanks Racing Roots and JustJim. I think that gives me what I was missing, and you're right, I have a terrible habit of overthinking, so I very much appreciate both you helping me out.

mrslysly

Justim is pretty much right on. I run CarboTech XP10 up front and the XP8 in the rear and they do need some heat to really bite well. They do work well on the street as they have decent bite cold.

There are always tradeoffs and you have to find the mix that is right for you. I like knowing that when I hit the track I can drive deep into the corner and scare the **** out of the passenger and not have to worry about brake fad. But then I'm constantly cleaning the car and have squeaky brakes everywhere I go.

Darkpoison187

iTrader: (1)

Thanx justjim very informative answered all the questions I had......I have a base A/T an thought I could just swap to sport suspension and then go sports sus brakes Man I was wrong

Rotarypiston

so ive read all this and maybe i missed it but hopefully i didnt.

based upon whats been said, the BBK's dont really help stop the car faster due to the ABS.

now when racing i know lots of racers actually race, they turn off their ABS. (includeing me)

so with ABS off and it not interfering with the car, would a BBK on the rx8 yeild benefits?

savedsol

Since some greases run different temps maybe a use/do not use. Such as the regular black silicone washes out and breaks apart at 500deg. I've recently used the Permatex Ceramic with good results - supposedly good for 2000deg. Then there's the silver stuff, the copper stuff. Not being a bonehead and forgetting to grease your slides everytime you change pads, etc.

Huey52

iTrader: (2)

Loctite Copper Grease works great. It's high temp resilient.

Grease anywhere the backside of the pads contact the caliper and also the pad slide channels. Of course don't get any on the pad-rotor contact surfaces.

heyarnold69

iTrader: (1)

The "brake rebuild kit" is like 10 dollars. make the investment... and I use synthetic high temp greese

Rotarypiston

anyone?

justjim

I'll try to keep this simple, the first thing to remember is the tires stop the car, the brakes just stop the tires. If the current brake setup can lock up the tires at will at some particular desired speed, putting a BBK won't stop the car any faster. It will however improve the resistance to fade. If fade is a problem with the current setup then yes the BBK will stop the car faster under those conditions that previously induced fade.

Your interpretation of why the BBK does not generally stop the car better is off the mark a bit. There is the issue of the tires actually stopping the car I mentioned above but also that in some cases a BBK may increase stopping distances. It's not the ABS that is the problem, it is the potential for inappropriate braking bias, that is the imbalance between the front and the rear brakes, which can sometimes result from a poorly designed (or poorly matched for your vehicle) BBK to prematurely activate the ABS at one end of the car and actually increase stopping distances. However, if you turn off ABS the problem will not only be increased stopping distances but loss of control and the higher biased end will lock up the brakes prematurely. My feeling is that, on a road course (not an autocross) unless you have a manual proportioning valve or adjustable twin master cylinder setup you should leave the ABS on when at the track. It won't significantly increase you stopping distances and for most of us mortals will decrease the distance and allow you to keep control of the vehicle under threshold braking.

cheapman

Appreciate this great thread, it was very helpful. I've talked to a few mechanics and they don't want to install brakes I buy and bring to them, well they'll do it but say other than proper installation they make no guarantees. I was going to just get the ones they normally provide. Anybody w/ experience with the quality of brakepads/rotors replaced by placing like Sears, AAMCO, firestone, etc? I saw sears sells Satisfied Gransport GS-6 ceramic pads which on tirerack seem to have decent ratings. Not sure about the other places.

justjim

My opinion is you are best served if you can find a mechanic who is not locked into a particular brand of brake pad. If you are using a shop like you described above they are using a particular brand and probably won't deviate from it. I would try to find someone who will at the very least get you the OEM Mazda pads. The Mazda OEMs are pretty decent for street use and probably better than alot of the standard OEM replacement pads. If you find the right mechanic and if you are tracking the car, maybe if you let him add his normal markup, he'll order some aftermarket pads of your choice .

I used Satified Grand Sport 5s on a previous front wheel drive car and my opinion was ehhh not so much, there are better pads out there.

The real answer to all of this is DIY.

Agalliasis

My new brake pads whistle all the time. My mechanic cleaned them many times but the problem still exists. I don't know if I buy the oem brake pads will give a solution to this headache...

justjim

Make sure he used the OEM shims and greased the back of the backing plate and shims. You should be able to get rid of the squeal. Some pads have a tendency to squeal more than others but I can even get my track pads to be silent if I do what I described above.

wcs

iTrader: (2)

Great thread.
Thanks for all info.

greenarixate

Jim, as everyone did say, this is a GREAT review indeed

I was about fork out a wide load of cash if it wasn't for this thread.

BTW, I found www.thepartsbin.com which offered OEM spec rotors for only $63 a pair - these are made by EBC.

I'm sticking with stock rotors and hawk hp plus since it almost does the same result since the braking system of our cars, along with ABS does a lot of the work already.

Slotted would be great of a car does not have ABS - which I experienced locking my brakes and killing cones during auto-x

greenarixate

correction: those were $63 per rotor. I decided the EBC dimpled and slotted. They do give further discounts when you call or use the chat box compared to what is posted.