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Round spinny bits and things that stop them.

Posted: Tue Jul 30, 2013 10:00 am
by zaxrex
What's this you say, the guy who has duplicates of everything is needing to borrow car parts?
Yes, it is true. All my rotors and calipers are a three hour drive away, and I can't get down there to pick them up.

First, a back story.
About six months ago, I was noticing some creeping/groaning noises when I applied the breaks, even while stopped. Pried the calipers a little and tried to wiggle the rotors, but the all seemed to be solid. I just though it was the lines rubbing on something as the pressure increased. Took it into a shop before I left for a trip and had them check it out. No problems.

This weekend, I decided to clean my wheels. I know, shocker, right? So when I do something, I do it all the way and I take off the wheels and clean the inside as well as the out facing bits. Nice and clean SSR Comps now.
I bring them back and start putting one back on, and I see some strange pattern in the hat. Look like up-swept feathers going from the locking pins to the outer edge of the hat. Look a little closer and some of them are a light dull grey. Go around to the other side and look there.
THERE ARE COMPLETELY CIRCUMFERENTIAL CRACKS THROUGH ALL THE MOUNTING PINS!!!!
Go back to the other side and spin the wheel a half turn, I see bigger feathers with TIPS SEPARATED FROM THE EDGE OF THE HAT!!!

So, Meth Blue is no longer in safe roadworthy condition. Turns out the locking pins are steel, the hats are aluminum, and the rotors are iron. Stop Tech super tech Frank said, oh yeah, that's normal. There is galvanic corrosion between the three metals. if the vehicle is driven infrequently and the parts are not heat cycled or are driven on roads treated with liquid brine solution, the steel pins corrode and actually expand in the locking holes of the hats. This causes increased pressure and do not allow the pins to slide to accommodate for frinction ring heat expansion. This puts stress on the hats that will eventually develop stress cracks.

So, long story short. Anybody have some stock rotors and calipers that I could borrow?

Re: Round spinny bits and things that stop them.

Posted: Wed Jul 31, 2013 6:08 pm
by ElZorro
sorry, no. good luck! lemme know if you need a hand with the work once you get them

Re: Round spinny bits and things that stop them.

Posted: Thu Aug 01, 2013 1:51 pm
by drwrx
I believe I have a full set of stock rotors, with very low mileage.
I'll look today after work.
No calipers though.

Re: Round spinny bits and things that stop them.

Posted: Tue Aug 06, 2013 10:09 pm
by Sabre
Oh damn, that sucks! I hope you got her back on the road!

Re: Round spinny bits and things that stop them.

Posted: Wed Aug 07, 2013 7:33 am
by drwrx
Sadly, I must have given the fronts out, I only have the rears.
Wait, didn't I give you the fronts during your swap debacle with the former cop?

Re: Round spinny bits and things that stop them.

Posted: Wed Aug 07, 2013 5:57 pm
by thermobox
I've got my entire BRZ front set-up. Caliper, Rotors, Pads, etc... I would assume that it would be a simple bolt-on affair with any GD/GG Impreza as I have the GC/GD 4 pot set-up on there now. Lemme know if you need em.

Re: Round spinny bits and things that stop them.

Posted: Fri Aug 09, 2013 10:34 am
by zaxrex
thanks guys,
as it turns out USPS delivered a 45lb box yesterday. Calipers, hats, rotors, lines, and pads.

Re: Round spinny bits and things that stop them.

Posted: Fri Aug 09, 2013 9:41 pm
by ElZorro
Now is that 45# of weight, or 45# of stopping ability, or 45# of line pressure, or... you need to be clear with these shipping companies.

Re: Round spinny bits and things that stop them.

Posted: Sat Aug 10, 2013 5:41 pm
by thermobox
I remember the last time there was a 45lb measurement invloved. It ended up being a HUGE turbo, right?

Re: Round spinny bits and things that stop them.

Posted: Sun Aug 11, 2013 11:41 am
by zaxrex
Hehe, that was 65# for the turbo. or was it 56#?
So I only have one set of wheels that will clear the Brembo conversion that Darrin put on. So I was supposed to trade a set of rear Brembo calipers for a "new" set of 4-pots from Subaru. Enter Philly ex-cop debacle. So the wagon now has 4-pots, and the sedan has cracked hats.
The brakes that I got now (wow, what a deal)! are a full Stoptech setup, I'm going to steal the hats and rotors to replace the ones I need, and keep an eye out for a deal on more hats and rotors so that both cars can have fully interchangeable parts.

Few, nothing like getting back into the mod game again... and I thought I was stopped.

Re: Round spinny bits and things that stop them.

Posted: Sun Aug 11, 2013 1:57 pm
by drwrx
It never ends.
Are the Stop Tech rotors the only way to go with the calipers?
Because, I gotta say, a new set of simple cast iron rotors for our vehicles are only around $50 a pop.
Just sayin'.

Re: Round spinny bits and things that stop them.

Posted: Thu Aug 22, 2013 11:44 am
by Raven
One piece rotors for the win. :P Yeah, the modding never ends. I'm even getting into modding with the car I was never going to mod. :P

Re: Round spinny bits and things that stop them.

Posted: Thu Aug 22, 2013 5:51 pm
by zaxrex
Raven wrote:One piece rotors for the win. :P Yeah, the modding never ends. I'm even getting into modding with the car I was never going to mod. :P
UPS man bringing you bigger rubber bands? :wiggle:

But Darin, you know I'm all about the bling...

So a little recap of events. Got the replacement use kit upened up and starting to work on it. Was a bear to get the hat fasteners off. Amazing what oxidation painted over with caliper paint can do. Got the hat off and confirmed that there were no stress cracks under the washers. While it was off, I decided to disassemble my CRACKED ones. I had no expectations that they would be easy to remove, so I put them on the grill at 600 degrees (C'mon, they are brake rotors and hats, like they have never seen this temp before...), let them cool down overnight as the grill went out. Next morning, doused them in liquid wrench, wrapped them up in plastic wrap, and stuck them in the freezer (OK, colder than they have probably been by about 20 degrees, but then who is counting). Unwraped them, and saw just how amazingly strong bimetalic differential thermal expansion is.
See before and after pics
Fasteners came off really easily after that. Mainly because the reciever studs had either cracked straight through, or sheared off when turning the bolt head.

Well that was fun and informative. Now, just for S's & G's I wonder how the fit would be with the new hats on the old rotors. Tried and tried, but just could not get the holes to line up. Receiver studs flush on one side are an 1/8 off on the other. Found the part number on the hat and looked it up.
This was a hat for the 332mm brake kit.
So was the rotor.
So was the caliper.
Everything more bigger.
:banghead: :banghead: :banghead: :banghead: :banghead:
The description on the sale was that these were take offs from a 2002 WRX with 17" wheels.
I asked how wide, "oh, stock width, there was no rubbing when I lowered the car". Ok, so 7"
Yeah, not so much...

So waiting for a reply from the guy about why the numbers don't add up.

Re: Round spinny bits and things that stop them.

Posted: Thu Aug 22, 2013 10:13 pm
by Sabre
Damn!

Re: Round spinny bits and things that stop them.

Posted: Fri Aug 23, 2013 10:06 am
by drwrx
I would half-expect those to sheer at high force / temp usage.

Re: Round spinny bits and things that stop them.

Posted: Fri Aug 23, 2013 4:48 pm
by zaxrex
Was told by StopTech that the corrosion on the anchor pins was in part a result of not getting the rotors/hats hot enough while driving. Steel pins oxidized and grew in the drive pin holes.
"our brakes love being hot, drives off moisture and narrows the pathway for galvonic reduction" I love it when they talk dirty...

Re: Round spinny bits and things that stop them.

Posted: Fri Aug 23, 2013 5:19 pm
by Sabre
zaxrex wrote:"our brakes love being hot, drives off moisture and narrows the pathway for galvonic reduction" I love it when they talk dirty...
:drool:

Re: Round spinny bits and things that stop them.

Posted: Mon Aug 26, 2013 10:36 am
by Raven
Wow, that is utterly terrifying to look at.

Re: Round spinny bits and things that stop them.

Posted: Sat Oct 05, 2013 2:02 am
by schvin
yikes!!