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      06-27-2016, 10:53 AM   #1
z4m_06
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Noob Questions

Hi guys - I don't have easy access to a lift. I just took a few photographs of each of the pads to see if you guys can use your expertise to answer a few questions.

This is what the OEM pads looks like after a 2 day track session at Pocono Raceway (SE Option 3). I squeezed in 120 laps in 2 days and only felt serious brake fade three times (same corner). The car is daily driven 50 miles and AutoX'd ~2 times a month. Brake Fluid: MOTUL 600.

After the track event, there has been significant pedal play (and the car goes to ABS very very quickly under heavy braking). Thought is that there is air in the brake system. The brakes feel very sketchy.

I am going in for a Motul 600 brake fluid flush this Thursday. Next track event is at Pocono Raceway on July 9th (MPACT).

Ferodo DS2500 has been suggested to me by a few local sources. I am considering doing Stainless Steel lines as well (with the brake flush).

Questions:
1) How do my brake pads look?
2) Do they need to be replaced based on wear and tear? (assuming no track driving)
3) Are the DS2500 recommended for my type of use (occasional track, daily driving, AutoX)?
4) Is it normal for the brake pad contact surface to be so uneven?
5) How do the rotors look?
6) Should I do a Stainless Steel line upgrade while the car is in for a brake flush?
7) Does taking photographs of the pad work? Is it enough to draw a few conclusions?

Thanks all!
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      06-27-2016, 12:14 PM   #2
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Quote:
Originally Posted by z4m_06 View Post
Questions:
1) How do my brake pads look?
2) Do they need to be replaced based on wear and tear? (assuming no track driving)
3) Are the DS2500 recommended for my type of use (occasional track, daily driving, AutoX)?
4) Is it normal for the brake pad contact surface to be so uneven?
5) How do the rotors look?
6) Should I do a Stainless Steel line upgrade while the car is in for a brake flush?
7) Does taking photographs of the pad work? Is it enough to draw a few conclusions?

Thanks all!
1. They look fine. Besides the fact the fronts are near the end of their life, and the rears are just about to get there.
2. No. Not immediately.
3. Yes.
4. Yes.
5. You'll need to take a micrometer to the rotor to tell for sure.
6. If it makes you feel better, sure. My experience is stainless steel braided lines on this car doesn't do much. The little bit of gain you get for pedal stiffness can easily be overcome from the inconveniences of having stainless steel braided lines.
7. Sure. It's enough for me to tell you why you're having that weird sensation in the brakes. You're now at below 40% of pad remaining. Which means the cup of the piston is in the extended position. On a sliding caliper design, this CAN introduce some longer pedal travel symptoms, especially during high performance applications. What you described is normal based on what I see in the pictures.

In the picture the front pads appear to have about the same thickness as the backing plate. Here's a good illustration between what fresh pads look like vs. worn pads:



You probably still have a few thousand miles of use on the street out of those pads, but I would not take them to an AX or track event in the near future, that's for sure. Once you replaced the pads (and pumped the brakes a few times), that solid pedal feel should come right back with a fresh set of pads.
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      06-27-2016, 12:48 PM   #3
z4m_06
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Quote:
Originally Posted by The HACK View Post
1. They look fine. Besides the fact the fronts are near the end of their life, and the rears are just about to get there.
2. No. Not immediately.
3. Yes.
4. Yes.
5. You'll need to take a micrometer to the rotor to tell for sure.
6. If it makes you feel better, sure. My experience is stainless steel braided lines on this car doesn't do much. The little bit of gain you get for pedal stiffness can easily be overcome from the inconveniences of having stainless steel braided lines.
7. Sure. It's enough for me to tell you why you're having that weird sensation in the brakes. You're now at below 40% of pad remaining. Which means the cup of the piston is in the extended position. On a sliding caliper design, this CAN introduce some longer pedal travel symptoms, especially during high performance applications. What you described is normal based on what I see in the pictures.

In the picture the front pads appear to have about the same thickness as the backing plate. Here's a good illustration between what fresh pads look like vs. worn pads:



You probably still have a few thousand miles of use on the street out of those pads, but I would not take them to an AX or track event in the near future, that's for sure. Once you replaced the pads (and pumped the brakes a few times), that solid pedal feel should come right back with a fresh set of pads.
Thanks a lot for your response, that was a lot of really good information.

Can you elaborate a little bit on the inconvenience of the Stainless Steel brake lines?
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      06-27-2016, 01:21 PM   #4
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Quote:
Originally Posted by z4m_06 View Post
Can you elaborate a little bit on the inconvenience of the Stainless Steel brake lines?
When you install stainless steel brake lines, you crack open the system to air. It can often lead to multiple flushes and activating ABS in order to fully purge the system of air bubbles. So the gain for having "stiffer" pedal can be negated if the installer isn't careful about sealing off the system during the install. Typically the lines come with a little cap to cap the hard line while you install, but some don't.

The other inconvenience is the fact that the steel braids don't flex as much as the rubber nylon reinforced hoses, causing some strain to be put on the fitting at the hard line side, or the fitting on the caliper side. Stainless steel braided lines have a slightly higher failure rate as they age, so you have to keep an eye on the two fittings on each side and make sure nothing is causing the line to twist, since said twist will lead to early failure.

Just minor inconveniences. Some swears by stainless steel braided lines, I had a set installed on my MZ4 Coupe, including complete rear lines, and the improvement was marginal. Of course, the fixed calipers from RacingBrake I installed has a set of Goodridge lines, I'm not going to complain.
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