Loose brake pedal feel

pkimM3r · 05-04-2013, 10:08 PM

When i first got the car the brake pedal was so sensitive.

Went to a track day yesterday and now my brake pedal feels really loose. I was on stock pads and felt some fade on one of the sessions.

Sort of feels like its just a permanent brake fade now. Went to fill in air at the gas station today and noticed a lot of material in the cross drilled rotors so i blew those out. Ive searxhed and all i see are posts about brake vibration after a track day. I dont feel that and the brakes still bite but have to depress the pedal more than normal. I am gonna buy track pads and swap out the fluid for higher temp rated fluid and bleed and bed properly.

Could it be brake fluid just boiled and created air bubbles?

Any suggestions/recommendations on what to do and a track pad that doesnt kill the stock rotors and doesnt need to get too hot in operating temps to work. I try to brake early to save brakes but i end up barely using the brakes on initial braking and squeeze more and more slowly as i get closer to turn in.

BimmerRob08 · 05-04-2013, 10:21 PM

I never experienced what you have after a track day, especially after brakes have cooled all the way. But I've experienced pad transfer causing vibrations and then it goes away after a few hundred regular DD miles.

I'd check your pads, see how much has worn off. Were they pretty new or half life before you took it to the track?

Flush the brake system with adding racing brake fluid, make sure its bleed good and free of bubbles.

Then fallow some of the pad bedding procedures found on here or on the net. Stoptech has a good info write on the procedure. I don't think you need to swop to track pads unless you'll be at the track a lot. But some dual purpose pads would be better than OEM street.

Good luck.
Rob

Vic311 · 05-04-2013, 10:24 PM

Quote:

Originally Posted by pkim1079

Could it be brake fluid just boiled and created air bubbles?

Most likely reason, the steam created from boiling water adds air to the system.

Flush your brakes and and use a high temp fluid.

pkimM3r · 05-05-2013, 12:50 AM

Pads were pretty new (5000miles on car). Pads are barely worn still pretty thick.

Im thinking its the boiling over. Need to get pads (thinking carbotech 8/10) and racing brake fluid.

Its annoying to change pads before a track day though but i guess its inevitable. Need some apex and some rs3.

Pzeros were alright on the track but need to swap them for some pss in the meantime.

Thanks for the feedback.

05-04-2013, 10:08 PM	#1
pkimM3r Banned 205 Rep 7,298 Posts Drives: m3 saloon in granny mode. Join Date: Dec 2009 Location: lost angeles iTrader: (0)	Loose brake pedal feel When i first got the car the brake pedal was so sensitive. Went to a track day yesterday and now my brake pedal feels really loose. I was on stock pads and felt some fade on one of the sessions. Sort of feels like its just a permanent brake fade now. Went to fill in air at the gas station today and noticed a lot of material in the cross drilled rotors so i blew those out. Ive searxhed and all i see are posts about brake vibration after a track day. I dont feel that and the brakes still bite but have to depress the pedal more than normal. I am gonna buy track pads and swap out the fluid for higher temp rated fluid and bleed and bed properly. Could it be brake fluid just boiled and created air bubbles? Any suggestions/recommendations on what to do and a track pad that doesnt kill the stock rotors and doesnt need to get too hot in operating temps to work. I try to brake early to save brakes but i end up barely using the brakes on initial braking and squeeze more and more slowly as i get closer to turn in.
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05-04-2013, 10:21 PM	#2
BimmerRob08 Major 110 Rep 1,311 Posts Drives: 2008 M3, Space Gray Join Date: Mar 2008 Location: KIKR (ABQ), NM iTrader: (0)	I never experienced what you have after a track day, especially after brakes have cooled all the way. But I've experienced pad transfer causing vibrations and then it goes away after a few hundred regular DD miles. I'd check your pads, see how much has worn off. Were they pretty new or half life before you took it to the track? Flush the brake system with adding racing brake fluid, make sure its bleed good and free of bubbles. Then fallow some of the pad bedding procedures found on here or on the net. Stoptech has a good info write on the procedure. I don't think you need to swop to track pads unless you'll be at the track a lot. But some dual purpose pads would be better than OEM street. Good luck. Rob
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05-05-2013, 12:50 AM	#4
pkimM3r Banned 205 Rep 7,298 Posts Drives: m3 saloon in granny mode. Join Date: Dec 2009 Location: lost angeles iTrader: (0)	Pads were pretty new (5000miles on car). Pads are barely worn still pretty thick. Im thinking its the boiling over. Need to get pads (thinking carbotech 8/10) and racing brake fluid. Its annoying to change pads before a track day though but i guess its inevitable. Need some apex and some rs3. Pzeros were alright on the track but need to swap them for some pss in the meantime. Thanks for the feedback.
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