Post
by VisualKei » Mon May 27, 2019 2:47 pm
Installed a set of Stoptech slotted rotors and Hawk pads front and rear with a refund from a long-running headache of trying to get Sandtler 2-piece brake rotors from Germany (gave up on it after 8 months). I noticed the swept area on the rear rotors was poor. For whatever reason, the rear pads are cockeyed or sticky, or wore improperly so I wasn't getting full contact area so I just decided to replace it while I was at it.
The front was straightforward to do. Everything was accessible and I could torque stuff back to factory spec.
The rears were a little more annoying. A new rotor and pads with shims made it too thick for the brake caliper to fit back onto the car, even with the piston fully compressed/twisted back in. I had to sand and lap about 0.020" off each pad before the calipers would fit back over the new rotor and pads without any drag, but I'm not too worried since the rears take forever to wear out anyhow, so the life loss is minimal. Slathered up all the contact points with Molykote M77 (M77 is 60%(!!!) molybdenum by weight vs most moly greases at 5-10%) so they'll never squeak with the high solids. Unfortunately, access to the brake caliper bracket is limited. I could only use a ratcheting wrench to get this part on and off, so I guesstimated at the 45lbft assembly torque. The only alternative as far as I know is to grab an E20 (I think) socket and pop off the entire wheel hub assembly to get more clearance for a torque wrench.
Getting the fronts to heat up to the point of getting an oxidation sheen (500-625F give or take based on color, and depending if it's the peripheral surface or swept area of rotor) for the break-in cycle was easy after some braking runs. The rears refused to get that hot. I tried breaking them in with aggressive reverse braking, which was more awkward than I expected.
Doing the brake break-in procedure gave me some experience in what the car is like under maximum braking power in a straight. The rear end is pretty wiggly if I stand on the brakes. Yet, I can't get the brakes to lock the tires, but I'm unsure if this means the tire grip is better than the brake stopping power, or the brakes need to be bled or have to be broken in a bit more to seat in properly. I don't have an isolated place to set up a braking test to see if stopping distances are proper. Lines were flushed and I installed MOtul RBF660 about 4,000 miles back so the fluid itself is more than sufficient. I have an experiment with some Vogtland rear springs and Bilstein B8s next week to see if that's a decent cheapo way to improve the rear feel, without having to dump my wallet into a Bilstein B14 coilover set.
Also slapped on some lift point stickers in the event I ever end up having to use a shop. I've been lucky so far that it's never needed anything I couldn't handle.
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