Im not sure if this is even anything at all, but here's my current "problem"...

For the sake of clarity...........I installed a new brake system about a month ago. I got Powerslot rotors, Porterfield pads, Goodridge lines and took the opportunity to replace the brake hardware.

Anyway, everything is working "fine"; that is to say, the car stops, but I have noticed a quirk that I need some help on.

When I stop from high speed (or actually just hard to really hard brakeing), The pads dont seem to "bite" the rotor as hard as they should. It just feels like I should be stopping a lot quicker, but its not. Its almost as if the car is "slipping" as it brakes (no its not the ABS), or maybe "slides" is more like it. Anyway, when I brake as usual in stop and go traffic, the bite is very agressive and I stop with no problems.

I did not "break-in" my pads as people have said, but I did do several hard stops from 35-40mph after they were installed. The fluid was replaced with Motul DOT 5.1, so I dont think its the fluid or fluid level.


Any ideas?

Thanks in advance!

 

If you are running the R4S as I would expect, they like to be pretty warm for optimal braking. I have some greenstuff pads and they are somewhat similar and after that initial "slide" as you mentioned like the bite is weak, the subsequent stop is much stronger/shorter. If you don't want that kind of issue then I would recommend a Hawk HPS or a Metal Master pad as they seem to bite immediately no matter the condition. And as always make sure there is no trapped air after bleeding the system after installing the new lines.

My current setup is stock sized front 2002 Hekimian Cryo'd rotors, greenstuff pads and goodridge lines, with stock rear pads/rotors. It stops very well but the first couple morning stops aren't very impressive.
Hope that helps.

 

Thank you. It does help.

I cant forsee me spending any more money on my brakes as the pads alone cost roughly $150. Theyll just have to stay there until its time to change them.


...I would also like to note that I found out today that my right front wheel bearing is bad.................

 

It sounds a lot like brake fade to me if it were truly just cold brakes then you would feel it on your normal braking in traffic and such. I would reccomend going through a good bedding process usually ten 60-10mph hard stops then let your brakes cool off for 5-10 mins before coming to a compleat stop. If you dont let the brakes cool first you will get excess build up on your rotors and get what is commonly reffered to as warped rotors.

 

When you replaced your brake pads did you have the surface of the rotors machined? If not, the pads need a bit more time (wear) to properly form to the rotor surface(s). I perform all of my brake repairs myself and very rarely have the rotors machined. Its totally unnecessary unless you suffer from brake sudder from warped rotors during hard braking. Just leave a little more room between you and the person in front of you and you should be fine. It took about a week for my last set of pads to start working properly.

 

....why would I resurface new rotors????

 

oops... sorry about that... I missed that small point... Still, it could be the break in period for your pads. I have experienced, what I though was, excessive brake fade under hard braking, only later to have the problem to disappear by itself... Its been awhile, how's your brakes today?

 

Well, I wouldnt know because its at the dealer getting both front wheel bearings replaced. And on top of that, If I understood him correctly, the control arm rusted in some bad places so they have to replace all that too.

Thank God its under warranty.

 

As one other person said, it is not the pad bedding or anything else. It's the pads. The Porterfields like to be warmed up before they will have a good initial bite. That's why they don't bite well at highway speeds - they are nice and cool from the wind. In city driving, they stay warm, so they bite better. The Porterfield is really more of a track pad IMO than a daily driver pad (comparable to the Hawk HP+).....as mentioned earlier, the Hawk HPS is a better option for good initial bite at all temps....

 

I thought more about your brake fade issue only during hard braking on the way home last night. I assume that the "Powerslot Rotors" have grooves (slots) that vent the rotors and help reduce heat during normal braking, thereby offering greater stopping power... However, if the total surface area on your new rotors is lower than your old ones (due to the area removed by the slots) it follows that, under the same circumstances (high heat during hard braking) you'll have less stopping power due to the lower contact area between the pads and rotors. Of course, with your new slotted rotors, it should take longer for the rotors to reach this temperature dependant condition, but once reached, your stopping power may actually seem less. I’ve often seen cross-drilled and slotted rotors that are huge compared to the stock rotors. This is done to bring up the actual surface area in contact with the pads. If your rotors are of similar size as your old ones, this stands to reason... Also, the slotted rotors are designed to offer superior braking over a wider operating range, this would account for you experiencing better braking during normal operation, but outside that range it is conceivable that you actual stopping power could be reduced. If you don’t think that rotors can get that hot, you haven’t seen a Car Rally Race at night. I’ve witnessed the orange glow from the rotors. Wouldn’t have believed that was possible if I never seen it for myself. Anyway, hope this helps…

 

umm....very logical and intensive there.....but, that it no way had anything to do with the post you quoted. Did I miss something?

...thanx for taking the time to type all that, I guess?

 

I've had the same setup for the past 2 1/2 years and I'm very happy with it. The bite is pretty good city and highway. Maybe it just needs time to break in.

 

My 2000 Maxima did the same thing - except I didn't have to use the brakes, it could just be going in reverse.. coasting or whatever. HORRIBLE scratching noise. At the same time though, driving normally (any speed really) there would be a light scratching noise as well. I replaced my rear pads (not even the rotors) and the noise immediately went away.

I can't explain why they went away.. but they did.