failsafe

Does it feel like there is a VERY SLIGHT amount of pressure on the rotor when no pressure is being applied to the brake pedal?
It's extremely slight and I only notice it when I'm on a slight incline- if the car is in neutral it doesn't quite roll like it did with the stock calipers.
I've been told that bigger brakes should feel like this because the (pad) surface area is bigger. I'm just wondering if I bedded them correctly or if the calipers are sitting too snuggly on the rotor when there is no pressure on the pedal.

Hope this make sense.

droideka

DUDE! I have the EXACT same problem. Residual friction from the binders. I jacked the car up and sure enough, the fronts DO NOT spin freely. You have the same weird wear in your pics as I do. Pad material on the outside/inside edges of the rotor and none in the middle. Check your MPG calculator. For the last four days I was averaging 15, 13, 11 MPG because of the drag. I only got 120 miles out of half a tank of gas! I usually hit 150-160 at half a tank.

Tonight I siphoned off a bit of brake fluid from the resevoir, but the wheels are still not moving freely. My MPG did go up significantly. I can't get in another bedding until Saturday morning, so I hope that does the trick to loosen up the binders.

failsafe

OK at least I'm not imagining it. I spoke with a few different people about this situation and the general consensus is that once the brakes get some miles on them (and the pads wear a bit) this should subside. I also spoke with a guy that is running Stoptechs on his WRX and said he initially had the same problem.

I was initially worried about the brakes and rotor heating up from the friction but I don't smell the brakes and I don't get any fade. I've done two bedding runs so far and plan to do at leaast one more this weekend.

Yes, I have noticed a minor decrease of about 2-3 MPG over the last tank. In addition to the bedding run I plan to do some hard driving on the local mountain roads.
Keep in touch and let me know how your brakes feel over the next few weeks and I'll do the same. I'll try syphoning some fluid out of the resevoir as well and see if it helps.

rouxeny

Excuse my ignorance, but how exactly does one go about doing a "bedding run?"

Nice brakes.

failsafe

Droideka- I've emailed Stoptech regarding the residual friction to find out if it's normal and if it goes away. I'll let you know as soon as I get a response

rouxeny- about 8-10 stops from about 60mph-5mph back to back with firm pressure on the pedal. Then driving around and letting letting the brakes cool to ambient temperature.

DZeckhausen

Here's a set of instructions I wrote up: http://www.zeckhausen.com/bedding_in_brakes.htm

DZeckhausen

Removing fluid from the brake reservoir will NOT reduce system pressure and will only serve to increase the liklihood that you will suck some air into the master cylinder as your pads wear down. (Although the low fluid warning light should come on well before that.) Please leave your reservoir full.

The reduction of 2-3 mph over your last tank MAY be due to the bedding in runs you've done. Going from 60 to 5mph and then accelerating at full throttle back up to 60mph and repeating this for a total of 20 runs in a single tank WILL have an impact on the average fuel economy for that tank.

When you slipped the pads into your calipers, did you have to tap them in with a mallet or did they slide right in? I've installed a few track pads which had backing plates that were slightly off and I ended up shaving a bit of material (just a whisker) off each side of the backing plate to make it easier to install the pads. A tight fitting pad may exhibit this sort of behavior until it wears in a bit. If you've got Axxis Ultimate pads in there, they probably slid in without a problem. I have never had any issues with them fitting.

failsafe

DZeckhausen- Thanks for the input. Unfortunately I'm still noticing a 2-3 mpg drop even after a new tank of fuel- however the residual pressure seems to be getting a tad better- still there but less so- I'm hoping it will subside eventually as the pads wear.

droideka

Dave, I meant just the tiniest bit of fluid. It was ~1/16" over the MAX line so I sucked off that 1/16th with a paper towel and for some strange reason my on-the-fly MPG improved. We have a real-time calculator in the Zs computer that we can re-set at any time to measure MPG. There was definitely a reduction in MPG as I re-set the comp several times this week to keep measurements.

Yes. I did have to tap mine in with a mallet even AFTER grinding down the edges of the backing plate. They (Axxis Ultimates) were so difficult to get in that I called Matt Weiss at StopTech to discuss on Monday and he said they did a revision to the retaining clips in the ST-40 since some people were complaining that pads were too loose and would *clunk* at low speeds.

I did another bed-in this A.M. to great success with a nice, even deposit of pad material on the rotor surface. My MPGs are back to normal and it appears that wearing down the pads a bit more does the trick. Thanks for your input!

failsafe

So the residual friction is gone? I'm going to do another bedding run this evening. Hopefully with sucessful results.

EnthuZ

iTrader: (2)

I installed my StopTechs a couple weeks ago, and I did not NOTICE a MPG drop. I did have to beat the sh*t out of the dust shield though to allow rotating freedom.

My Ultimate pads required a lot of.....persuasion/filling to finally slide in. But now, they are a real B*tch to remove. Do I need to remove the caliper to remove the pads? I'm taking my Z to Blackhawk Farms next Monday, and I NEED to install my Panther Plus pads. Any suggestions? Pointers? Tips?

DZeckhausen

It was coincident with, but not caused by the removal of 1/16" of brake fluid from the top of your reservoir.

Quote:

Yes. I did have to tap mine in with a mallet even AFTER grinding down the edges of the backing plate. They (Axxis Ultimates) were so difficult to get in that I called Matt Weiss at StopTech to discuss on Monday and he said they did a revision to the retaining clips in the ST-40 since some people were complaining that pads were too loose and would *clunk* at low speeds.

I spoke with Matt and Bob at StopTech on Wednesday, following my installation of a front kit on a brand new 350Z for a racing instructor. I was concerned about the backing plate variation with the StopTech Club Race (Kerr Friction) pad. It turns out, the issue is indeed the new abutment plates that are in the caliper. There's now a bump in them to keep the pad from clicking when going from forward to reverse and I think they overdid it.

It may be possible to loosen the abutment plate a bit by putting the car in reverse and doing a few hard stops from about 20 mph. Obviously, you should be careful when trying this STUNT out!

failsafe

Dave-
In your experience is the residual frition Droidkas and I have both been experiencing normal with bigger brake kits? BTW- I'm running the Axxis pads.

In addition I've noticed a clicking in hard, sharp cornering at high speed. Droidekas- you get this?

Thanks,

DZeckhausen

No, it's not. I think it's a function of the new abutment plate feature (bump). I had a 4-wheel E46 M3 customer experience the same thing the first few days following installation, but it went away.

At this point, I think it's merely an annoyance, but I'll keep you posted if anything develops. If you continue to see this behavior on your own car, please let me know.

When I do any major modifications to my car, my gas mileage tends to tank for a few thousand miles! I put an M5 limited slip differential into my wife's 2001 540i 6-Speed and the first couple of tanks of gas dropped to about 12 mpg from a previous average of 21. After I stopped turning off the dynamic stability control system to do burnouts and power slides, my mileage went back up to 20 mpg!