[InceptionBW]

Just installed these brakes along with some Hawk 5.0 pads and new lines.
Was testing them briefly tonight after using a motive power bleeder and coding SPBR.

So far, I have a very soft brake pedal on first press, and firms up on subsequent presses. During the bleeding process, I didn't see any more air bubbles before putting the wheels back on. Unfortunately, I ran out of brake fluid to try the DSC bleed, but I'm guessing there's probably some stuck air somewhere.

I also noticed that on the driver side, the outer edge of the disc still had the initial coating where the pads didn't touch. All the other rotors are even. Could this be an indication that air might be trapped on this side or do I have two separate issues?

Here's an image of what I'm referring to:

[Watsey]

M-Performance brakes had a rep for soft pedal, and it wasn't cured by coding big brakes in the relevant module.

Hopefully you spotted that you were running low on brake fluid before the level dropped below critical in the brake fluid reservoir. You really don't want to have got air in there.

There are two bleed nipples on each caliper. Bleed from the inner nipple first (nearest the dust shield), then the outer. Continuously tapping the caliper with a rubber mallet as you bleed it is a good way of dislodging any small air bubbles that may be trapped.

Once you're certain that the braking system is fully bled, you should bed the brakes. The surfaces of the pads and discs need to have been properly settled/mated first, just through normal driving for (say) 50 miles.

You're going to need a quiet stretch of (ideally) straight road for this.

Warm the discs and pads by doing some light-medium braking.

Do 10 consecutive (back to back) hard stops, 60mph down to 5mph, almost enough to trigger the ABS. Do not allow the car to stop. Immediately you hit 5mph, accelerate back to 60 and repeat.

The discs and pads will get VERY hot. You should expect some smoke, for them to smell very hot, and ideally you want to see a blue-ash tinge on the faces of the discs (which you'll only be able to check once you've parked the car).

Then go for a LONG drive, probably 20 miles, to thoroughly cool the brakes. Plan your route so that you won't need to bring the car to a stop, therefore avoiding very hot pads creating localised thicker pad deposits on the discs.

Once the braking system has been thoroughly cooled you can return home and park it overnight to cool to ambient.

I wouldn't worry about the unswept area on the discs in your photo. As long as the pads have been fitted correctly it's just indicating that the pad contact area is slightly smaller than OEM. Some pads are chamfered to aid the pad mating/bedding process, but this is normally only on the short edges of the pads (i.e. not along the longer radiused edges).

[InceptionBW]

Yessir, I haven't bedded the pads yet but after adjusting the pads a little today I see that they are making full contact now!

I still feel that my brakes are a little too soft, going to try to bleed again once more when fluid arrives and follow your advice on the bedding.

You think I should just go straight to DSC bleeding instead of via a power bleeder? Getting Rheingold and all that installed as we speak..

Thanks

[Watsey]

I use a pressure bleeder and it works fine. No real need for anything fancy or expensive.

20psi is sufficient to push fluid through the braking system, and makes the process of bleeding at the nipples very easy.

The correct sequence is LR, RR, LF, RF.

I also have someone do 2 or 3 full travel brake pedal pushes (slowly) while I'm bleeding the first caliper - this makes sure that there's also fresh fluid in the master cylinder.

[cfm56d7b]

InceptionBW, did you install stainless steel brake lines?

[InceptionBW]

i'll try to pressure bleed again and see if I can get those bubbles, will report back.

Yes I did install stainless steel brake lines, any advice there?

[InceptionBW]

I used Rheingold today but kinda confused by the order of bleeding it was telling me.

Basically it said to do Left rear, left front first, with no way to ever do the right side unless i restart the procedure which will then ask me to do the left side again (even though it works for the right as well)? Also there was no way to pause so that you can bleed both valves in the front.

[FaRKle!]

Originally Posted by InceptionBW

I used Rheingold today but kinda confused by the order of bleeding it was telling me.

Basically it said to do Left rear, left front first, with no way to ever do the right side unless i restart the procedure which will then ask me to do the left side again (even though it works for the right as well)? Also there was no way to pause so that you can bleed both valves in the front.

If you read closely (I missed this too the first time I did it), the ISTA DSC actuation bleeding procedure is supposed to be done after conventionally bleeding all four corners.

[InceptionBW]

ok awesome, so it's normal

[InceptionBW]

After pressure and inpa+ bleeding, brakes are working flawlessly

[silentF30]

These are just standard m sport brakes off a m package not the big blue msport? Where did you purchase?

[InceptionBW]

No these are not from the M sport package. They're a little different than the blue ones , front rotor is 370mm and all rotors are dimple/slotted. Got them off a dealer on ebay.

[deepghosh]

Originally Posted by InceptionBW

Yessir, I haven't bedded the pads yet but after adjusting the pads a little today I see that they are making full contact now!

I still feel that my brakes are a little too soft, going to try to bleed again once more when fluid arrives and follow your advice on the bedding.

You think I should just go straight to DSC bleeding instead of via a power bleeder? Getting Rheingold and all that installed as we speak..

Thanks

How did you adjust the pads? I just installed my kit and noticed a small portion of the front rotors near the hub are not making contact with the pad

[InceptionBW]

Originally Posted by deepghosh

How did you adjust the pads? I just installed my kit and noticed a small portion of the front rotors near the hub are not making contact with the pad

It was at a very slight angle initially so I took out the pins and aligned them more evenly before locking it in. Lastly, make sure there is absolutely no air in the lines so that the new pistons can fully press.

[Junaed08]

i'm having a similar issue where i've had the M-Performance brakes put in. Brakes have been coded and with ISTA the brake bleeding routine has been done yet i still have a spongy pedal? Can anyone help?

[NickTheQuick]

Originally Posted by InceptionBW

After pressure and inpa+ bleeding, brakes are working flawlessly

May I ask what inpa+ does? Is it just for the DSC?

[dbldangertilt]

Originally Posted by Junaed08

i'm having a similar issue where i've had the M-Performance brakes put in. Brakes have been coded and with ISTA the brake bleeding routine has been done yet i still have a spongy pedal? Can anyone help?

Coding shouldn't effect pedal feel. I'm told it only modifies how our brake temps are calculated due to increased thermal capacity.

You have air in your system. Pressure bleed the system again. Maybe get on ABS a few times before you bleed. I never do the ISTA bleed procedure.

[SD Convert]

Originally Posted by dbldangertilt

Coding shouldn't effect pedal feel. I'm told it only modifies how our brake temps are calculated due to increased thermal capacity.

From personal experience, I can say that it also impacts front/rear braking balance.

[PininMargherita]

The brake pads are the same between the 340mm and the 370mm, so their contact patch is the same. This leaves the 370mm rotors with some unused rotor material around the edges.

[Skyhigh]

The above makes no sense - then the unused diametrical space on the rotors must be min 3 cm..... that's is A LOT:



I don't have that much area without contact on my M Sport brakes.

[SD Convert]

Originally Posted by PininMargherita

The brake pads are the same between the 340mm and the 370mm, so their contact patch is the same. This leaves the 370mm rotors with some unused rotor material around the edges.

The calipers for the 340mm rotors aren't the same as those for the 370mm rotors. The mounting ears on the calipers for the 370mm rotors are 15mm longer. This puts the pads at about the same distance from the outer edge of the rotor for both sizes.

The additional distance from the center allows the same clamping force to generate more braking force. Also, the thermal mass of the rotor is increased. Finally, the cooling vanes extend further out, increasing the cooling airflow.

[PininMargherita]

Originally Posted by SD Convert

The calipers for the 340mm rotors aren't the same as those for the 370mm rotors. The mounting ears on the calipers for the 370mm rotors are 15mm longer. This puts the pads at about the same distance from the outer edge of the rotor for both sizes.

The additional distance from the center allows the same clamping force to generate more braking force. Also, the thermal mass of the rotor is increased. Finally, the cooling vanes extend further out, increasing the cooling airflow.

Correct. The calipers aren’t the same. I said the brake pads are the same.


I own two cars one with 340 and the other with 370mm calipers. They use the same pads.