Brake pad recommendation and how-to info

[praedet]

Take a screw driver, put a rag on the rotor, and then force outward on the old pad. That will give you enough room for the first new pad. Then, repeat that on the other side. It will be tight, but that is the best way w/o removing the rotor...

[Legend]

Thanks guys. I am brand new to brakes (if that was apparent before). The UPS man just brought me these:

 

http://beeez.com/lgt/newpads.jpg

 

http://beeez.com/lgt/newpads2.jpg

 

Now I see just how bad my current pads are! OUCH!

[Legend]

I put the new pads on Friday night. Despite the fact it was my first time replacing brake pads you are right, Praedet, it was very easy on the Stoptechs. (Are the stock back pads equally easy to replace??).

 

3 of the 4 pads looked as ugly as the one pictured above with that crack going right down the middle.

 

Zeckhausen recommended NOT bedding the new pads right away since the old pads likely left deposits on the rotors. He advised I wait a few days so I haven't done it yet. (What exactly does bedding the pads do, anyways??)

 

I still have unwelcome noise from the front right, although the judder is gone. When I first put the new pads on I could hear scrape-silence-scape-silence that was speed-dependent... like the pads were hitting the rotors slightly every rotation. This happened whether I had the brakes applied or not. It still happens now, but only upon light application of the brakes. I'm hoping that I am just wearing off deposits from the old pads, but I'm concerned I might have another problem. Any thoughts on this? Thanks in advance.

[fweasel]

ST calipers can be noisy, how old are they? The floating rotor hardware can also become loose, between the rotor disc and center hat pieces.

 

In theory, driving around on those new pads w/o bedding them in should help them stay abrasive longer and remove old pad deposits. But, bedding them in can and has worked to remove them as well. Keep in mind, you bed new pads in for two reasons: 1) to prevent green fade - cook out the resins that bind pad material together, which when released, cause a gas build-up and the pads fade like a motherphucker. This is a one time thing. 2) to properly transfer a layer of even pad material to the rotor surface so they can work in their adhesive range.

 

Because the pads have not been bed in, they will green fade when first used hard, keep that in mind. You're well on your way to becoming an experienced brake DIY. The next step is to hit the StopTech website and read just about every FAQ and whitepaper they have posted. Once of which includes all the specifics to a proper bed-in process, whatg's happening, and why it should happen.

 

Good luck.

[Saul_Good]

I really love my carbotech xp12's F&R with Prospeed GS610. It's been so consistent with the bite and stopping at the track. It's a bit of overkill with the tires I currently have, but i'll fix that with some R-comps after my current tires are through.

[Legend]

ST calipers can be noisy, how old are they? The floating rotor hardware can also become loose, between the rotor disc and center hat pieces.

 

Thanks a lot, fweasel. I've definitely got an issue. The front right makes way too much noise when braking, then continues to make noise when I let off the brake.

 

The noise eventually subsides and I think the fact that it subsides is key. It really suggests that something is loose and continues to go to a loosened position everytime I brake, and the only way it straightens out again eventually is to continue rubbing until it is straight again. I need to get that wheel off and inspect whatever holds the caliper in place.

 

Thanks for the info on bedding. I wonder if I go too long without bedding will it hurt long-term performance?

[fweasel]

Thanks for the info on bedding. I wonder if I go too long without bedding will it hurt long-term performance?

Nah, think of the thousands of millions of people who get brake work done and just drive away from the shop normally. Its more important with high performance pad compounds for them to perform optimally. If they don't get bed in, the pads will be pressing against a bare rotor and you will loose braking performance.

[Legend]

Still having problems here, I think. The front right, which had become noisy with the old pads, continues to make noise. The left side is silent. The noise sounds like scraping when I apply the brakes, and then continues in a speed-dependent manner (scrape-silent-scape-silent-scrape-silent, etc.) for several rotations of the wheel after I let go of the brake, then completely quiets 2 to 10 seconds later.

 

I suspected something might be loose, so I pulled the wheel this a.m. and inspected every bolt that holds the caliper, bracket, etc. and every bolt I put my wrench on was just as tight as could be. I removed the new pads, which have been on the car for 4 days or so. I took several pictures of the pads. In both the pads, but primarily the inner pad, there is a deep groove developing on the outside of the pad. Take a look:

 

http://beeez.com/lgt/bothpads.jpg

 

Here is the inside pad, with a close-up on the outside edge. It's not flat any more.

 

http://beeez.com/lgt/innerpad.jpg

 

The inside edges of each pad seem a little roughed up too, but not bad.

 

http://beeez.com/lgt/insideedges.jpg

 

I felt the surface of the rotor, and there is a small lip on the outer edge, but no bigger than that on the left rotor, which is silent. When I re-installed the pads, I made darn sure they were fully inserted. You can see the outside edge of the pad and how it rides on the lip of the rotor when the pad is fully inserted:

 

http://beeez.com/lgt/padinserted.jpg

 

I bolted everything up, put on the wheel, and the problem persists.

 

Any thoughts on what is going on here? Perhaps I'll just be fine once these outside edges are worn down to fit(?) In the pictures the left pad is the inner pad.

 

I'm stuck on this...

[fweasel]

My theory on the brake pad edge wear issue would be that the old pads did not extend to the rotor edge, thus, as the rotors wore, the very lip of the rotor surface stayed at its original thickness while the pad/rotor interface wore down progressively.

 

Now, your new pads to extend to the rotor egde, which essentially has a machined high spot to it and is carving out the edges of your new pads as a result. Makes sense, but all a guess without ever having seen your setup, past and present in person.

 

Oh, and check out this thread on a 300ZX forum about possibly a similar noise. Not sure if the sound clip is still hosted.

[Legend]

I think you are right, fweasel. In fact, I emailed zeckhausen (#1 Stoptech dealer) and he suggests exactly what you are saying. He says I should bed them now (I was waiting first because I wanted to wear off deposits from the burnt pads and then I waited due to my uncertainty with the noise). Sounds like it will go away with more driving and bedding should accelerate the process.

[mwiener2]

you could get the lip machined off