Hello guys..

I have a HUGE problem with my R52 '06 Cabrio S A/T... maybe one moth ago I went to a track day that obviously my Mini cant handle it..

When Im driving and the red light is on... Im pressing my brake pedal (with Drive on) and second's later the car starts to move... and my brake pedal starts to feel spongy and continuously go more to the bottom..

If i want to brake, it brakes, but many times later the pedal is more to the bottom.. but when I stop to pressing down the brake pedal it returns to the normal height..


I already went to ask to 3 mechanics (that only check my car with their eyes... ) but they told me that the problem is the Master Cylinder (pump) and many mates told me that can be the air in my brakes by the high temperature that it suffered at the trackday.


*Some mechanics told me that if I have air in the lines, the pedal will not return to the normal height...

*The level fluid is ok.

*I already bought ATE BLUE RACING... just read it that the ATE isn't a good fluid for BMW/Mini.. i will search MOTUL.


HEELP!!!
Because i dont want to leave my Mini at the local dealer... the last time they changed the fuel pump and a pulley just to discover WITH MY HELP that it was the fuse box that it was dirty.... and yes.. i have to pay for everything....




This is the poor mini...

 

Oooh, with the red BRAKE light on, you need to determine if you have a low-fluid level issue, or something else.
You should ALWAYS bleed the brakes first to isolate the problem; yes, it could be air in the brake lines if you cooked the fluid.

- Erik

 

I will do it so... bleed the fluid... if the bleed do not fix my brakes... i will loosing the new fluid :(

hoping that fix the problem

 

Overall, fluid is CHEAP in comparison to what it could be...

- Erik

 

The act of bleeding brakes, ifdone right will cause the loss of maybe 50% of the fluid you bought...
Since the light went on, the level apparently went low...
So refil, and a full flush....a bleed only gets air out, but the old fluid might be moist and dirty...with dot4 it needs to be done much more often than most folks do it, espically if you track a car.
Superblue is ok....but motol has better specs for the $$$.

 

Track day + spongy brakes = boiled brake fluid. Flush brake fluid and bleed system. Use DOT5. My 2 cents from more years of track time than I care to admit.

 

I've had good luck with this pressure bleeder by Motive, not to expensive and may be worth considering. See link below:

http://www.amazon.com/Motive-Product...6064158&sr=1-1

 

I use mine on every car I own!

 

NO, NO, NO!!! Never, ever use DOT 5! Use DOT 4 or DOT 5.1. There is a HUGE difference between DOT 5 and DOT 5.1. They aren't even the same thing. DOT 5 is silicone based and should never be used. Period.

 

Reading on internet that if the booster were the problem... my brake system will feel really hard and the bleed was done without solution... so...

Will be the brake pump.

Here in mexico the price is 257 dllrs.

 

There's a how to of how to check or fix the O-RINGS of the brake pump?

 

Anybody know's if the O-RINGS can be the problem.. if this piece is in bad conditions it let the air go out doing no pression inside the pump right?

 

Brake booster usually first feels hard....then pedal will sink to the floor...(if leaking inside), so kinda fits your first post....
did you smoke your brakes real bad? Any fluid loss?
If you cooked you pads or glazed the rotors/pads, it could feel linda similar...
Before you self diagnose and spend $$, be sure the pads/rotors are not bad...
it is kinda odd it felt ok, then got squishy on+after a track day....

 

Will check it in these days... hoping the booster was not the problem.. more expensive haha

 

IF you got spongy brakes now, Don't use the ATE brake fluid. I've seen it cause spongy brakes many times, I believe it does something to the seals and ruins them.

 

Yesterday they check my car and found that the brake pump has a small hole (crater) in the aluminum part...

 

My car is working ok now... Just a little spongy but it brakes... It has a new brake pump... Because the old one, the old owner make a mistake with the fluid.. She puts engine oil in the brake pump.... It was red with ambar!!!!!! And all the o rings were bigger and for that reason it loose all the presion..

They had to clean all the brake system to rove the dirty and ugly oil and replace it with the ate blue.
Thanks to everybody!