Two or maybe even three master brake cylinder

AxelBerlin · #1 (**permalink**) 11-19-2009, 09:53 PM

Hi Guys,

slowly I'm ripping of the last hair which is left since I have the second master brake cylinder in and it looks like also this one is leaking. It started as I got a new one after the old one leaked and had a sagging pedal. The replacement worked for around 7 or 8 month and started to leak into the booster. So I got for free

since it was still under warranty. Also this started to leak after just two month and just a couple of miles of driving.
No I have the third one in but there is still brakefluid disappearing. Non of the repaired ones got to the point of the sagging pedal but the leakage is annoying since the car needs to go out for service. Has anyone had this? According to my mech he had a couple of bad mc's but it looks like I had the most

Axel

**Geoman** · #2 (**permalink**) 11-20-2009, 04:56 AM

I suppose all thee MC could be defective, but could another component be failing or misadjusted to cause the MC to fail? You mentioned that the second MC leaked into the booster, did the first and third units also leak into the booster? Just thinking of what could be the common denominator if it's not the MC. Could the booster's actuating rod be misadjusted somehow, thereby pushing to hard on the MC causing damage to the seals? Have you removed the pivot cover behind the booster to see if the linkage is ok? Seems unlikely to have a problem there, but just trying to throw out some possibilities to get the conversations going!

AxelBerlin · #3 (**permalink**) 11-24-2009, 11:40 AM

OK, today I checked again after roughly 500miles the level of the brake fluid and bang, it's gone from full to half. Looks like that the next one is due.
It must be something else than just a bad lot of MCs since this one is from a different manufacturer. I will bring the car in on Monday since Thanksgiving is keeping me out of town. I will get more input next week.

AxelBerlin · #4 (**permalink**) 12-01-2009, 03:08 PM

Ok, it's official: I got a new one. Also the last was leaking...let's see how long this one will last....

juan carlos · #5 (**permalink**) 12-02-2009, 08:59 AM

Le respondo en Castellano (Español) a mi me paso lo mismo,puse 3 bombas y todas "defectuosas",pero el problema era que monte las pinzas de freno mal

LA DERECHA en el lado izquierdo
LA IZQUIERDA en el lado derecho

Compruebe que el purgador de de la pinza de freno este en la parte alta de la pinza de freno.

SALUDOS
Juan Carlos

PD-Siento responderle en Castellano

AxelBerlin · #6 (**permalink**) 12-02-2009, 06:53 PM

You will not believe it but I picked up the car today and barely made back to work and the Brake light came back on. The reservoir went from full to empty in less than 5 miles so MC number 4 is on it's way tomorrow. I can not believe it, it is the third MC broken, it's the third manufacturer and still the same thing. I start to think that there is more to it.

BTW, I can not understand Spanish, what is Juan message?!

**Geoman** · #7 (**permalink**) 12-02-2009, 07:08 PM

The brake fluid has to be going somewhere. With a new MC I assume the internal seals are fine and therefore fluid is not going into the booster. So, where do you see wet areas on the car? Following the brake lines from the MC to the front wheels and to the back wheels via the compensator and line splitters. Any leaks there? Remove the wheels and see if one of the calipers or connections is wet. Rubber hoses intact? Maybe put the car up on jacks, fill the reservoir and have someone pump the brakes while you investigate all these areas?