Took my brakes apart..
 

Well in preparation to install my new ART front's in about 2 weeks, I decided to put my car up on jackstands today and try to disassemble the front brake assembly. I had a buddy come up, we knocked on the two bracket bolts with a hammer a little bit (shock therapy works wonders!), and took the caliper off the front-left disc.

After setting the caliper on a maksshift brick platform, we visually inspected the rotor. It had a couple of small gouges running the entire circle of the disc. and thee distinct impressions of a brake pad on the outer face of the rotor. This part puzzled me the most because I'm always careful not to sit with hot pads pressed against hot rotors.. Hmm..

So we looked around for a nut that would fit in those small holes on the rotor to push it off the hub. No luck.. Can anyone give methe measurements on that nut so I can remote the rotors with ease in two weeks?

After re-attaching the caliper (we didn't remove pads--I'm not ready to start screwing with fluid just yet.), I went for a drive.

The wobble & shake that would rattle my bones when I so much as tapped the brake pedal was all but gone. There was a little shake when I really beared down on the pedal, and it still took more pedal than normal to bring the car to a halt, but the shake was very much reduced..

20 miles later it was back, though.. I guess I'd better drop this check in the mail to ART..


-Adam

The factory service manual states that it's an 8 mm bolt. From experience, lightly tapping the rotor with a hammer with the caliper off also works if the rotor isn't stuck on there too tight.

Bryan

8x1.25, to be exact. And rattling the rotor with a few good shots to the 'hat' section of the rotor with a BFH is the preferred choice of most techs. Just don't hit the studs, the working face or the center of the hub that protrudes through the rotor. Being in NH I'm guessing that there's a fair bit of rust so a good spray of WD40 or similar will also help. Just don't try to remove with the bolts only, whack it a few times to shock it loose. If you don't you'll probably just pull the threads out of the rotor.

Beav

Cleaning off the hub section with a wire brush and emery paper can also help make room for the rotor to slide off.

Personally, I've never had a problem - my rotors have always slid right off.

But if you want to help eliminate this problem going forward, brush some anti-seize on the mating surface when reassembling.

Re: Took my brakes apart..
 

From what I read, I can't understand why you thought things might have changed. You didn't replace the pads or replace the rotor. Maybe I'm confused, but did you expect a change? :confused:
Don't be concerned about the radial groove. Pad material can very in makeup in regions and can be harder in spots. These hard spots can groove the cast iron rotor.

A cheaper way to eliminate the shudder is to have the rotors turned while on the car (or turned by a shop which can hold a tighter finish tolerance with a standard brake lathe). The shop manual calls out a tolerance that cannot be attained by older, sloppier lathes. I had a significant vibration in the brakes after I had the rotors cut by a local shop. Took the car to my local dealer and had them touched up with the on-car system and they were fine! I just replaced the ORIGINAL rotors with 136,000 miles and three cuts, about 4 months back!

Good luck
Todd

Todd-

The thing is, I wasn't expecting ANY kind of improvement.. I mean who just takes something apart, puts it back together exactly the way it was originally assembled and expects it to work better?? well.. maybe some mechanics, but not me. I was kind of amazed to feel a minor improvement, but a day later the rotors are feeling just as warped as they were before I took them apart. I'm curious as to what it was, though.

Anyway, I was thinking about just getting these rotors turned instead of replacing them. After all, I can pay something like $15 a pop to have them turned on the car.. Well, I'm usualy pretty hard on brakes. Unfortunately for my car, I'm 20 years old and I usually drive like it, so I figured that I might as well have at least a minor edge over stock rotors..

My plan is to have the rear rotors turned on the same day I replace my fronts. I'm also planning on turning the old front rotors once they're off the car and either holding onto them in case I crack one of the ART's (unlikely) or someone wants to buy a pair of secondhand rotors to tide them over for a couple months until they can afford something slotted or cross-drilled.

The impression I got from practically everyone except you is that the stock rotors are too thin to begin with, and machining them down is just asking to have them warp again, which is why I've decided to buy a high-performance set instead of a new set of OEM's..

-Adam

I see where you're coming from but
 

I doubt the ART rotors themselves are thicker than the OEM's. ART doesn't cast them, they buy castings from another source (Brembo, Beck, EuroRotors) and then cryogenically treat them. The ONLY way they could be thicker is by reducing the distance between the front face and the rear face. If they were thicker from front face to back face they wouldn't fit between the new pads in the caliper. Whatever you do, break your new rotors in per the procedure from the supplier. Again, I've never had a problem with warpage, but I believe that the makers of the rotors know far more about the properties and performance of cast iron than I do!

Please don't think I'm knocking aftermarket rotors as I used cross drilled KVR's (cast by euro rotor) on my car and am having an extra set of calipers powder coated black to install this spring. My 17" wheels show the rotors and calipers too much to leave them nasty looking (shamelss plug to the pics in my locker).

Todd

Just to be perfectly clear..
 

I never said that ART rotors were any thicker than stock rotors. I actually might have implied it, but I didn't mean to.

I think I'm correct in saying that a set of slotted or cross-drilled SVX rotors will generally actually have LESS surface area avaliable for the pad to grip unless the rotor itself has a larger diameter. However, they open up MORE surface area to the passing air, allowing for more efficient, effective, and uniform cooling.

And don't worry, I don't plan on driving like I'm 20 until everything's properly broken in :D


-A

ps. powder-coated calipers? good call.. I think I'm going to paint mine a totally sweet aftermarket color: Rust ;)

You might like this discussion Adam
 

http://www.subaru-svx.net/forum/show...&threadid=1950

This one went on a while back. Lots of gory details that I didn't want to try and quote and re-type!

Have fun and enjoy your brakes!

Todd

too.. much.. information.. carbon fiber.. stainless steel.. head.. going.. to.. explode.. dual caliper setups.. coefficients of friction.. god%*$( engineers.. head swimming..

after reading through most of that thread, i am now an expert on brakes and will be installing a dual-rotor system with sixteen calipers on each rotor. Even-numbered calipers will have carbon fiber pads, and the odd ones will be using a prototype brake pad made of very precise ratios of bellybutton lint and rolling papers.

I'll post pics soon..

-Adam