First run of the year

[deetes]

Pre-flight checks completed OK. Fueled up. Roof down. Chocks away. Having a great time playing with an M3 till the brake pedal took a liking to the floor. Bye bye beemer. Stopped and checked for leaks, checked front hubs for excessive heat build up. Everthing checked out ok. The pedal would come back with a couple of pumps but would go away again after a short time. Drove home slowly. Jacked it up today and rechecked everything, but I can't see anything and more importantly the pedal's back to normal today.

Any ideas???

[GV]

Sounds like something hydraulic. Have you checked your fluid level in the servo? Any fluid loss there would be a strong indication you have a worn seal somewhere that needs replacing.

[deetes]

Nope. Checked fluid level when it first happened.

I thought maybe sticky pads causing overheating and hence boiling the fluid, but pads are free and the front hubs were cool.

Another thought was master cylinder leaking internally, but that would have shown up today and the pedal's perfect today.

[combine]

You did well to 'play' with an m3 as they are quite serious motors , not as characterful as a big wedge but not boring anyway !

[blaineuk]

have you checked the rear's

[SEvans]

I would have thought the most likely cause is that you have boiled the fluid. How long is it since it's been changed? However, this did happen to me some years ago and I ended up replacing the master cylinder.

[brummiewedge]

Mine did this, i replaced the Master Cylinder.

[blaineuk]

have you had a problem with pedal travel before this, as i have a lot of travel on mine a present and can not sort it. only thing left to do on mine is to change master cylinder. what are they off and how much??

[badredwedge]

blaineuk said:

only thing left to do on mine is to change master cylinder. what are they off and how much??

Richard Thorpe about £59 + Post.

[deetes]

blaineuk said:

have you checked the rear's

Checked that they weren't binding with the car up on stands. Pedals perfect now and all the wheels are rotating freely. Haven't physicaly checked the rear pads are loose, but if they were sticky they would cause resistance to turning and this is not the case.

Anyway cheers for all the help.

[350zwelgje]

Looks like a worn seal in the master cylinder to me.
Worth getting a kit and refurbish it.
Oh no, another to do on my list as well now. No problems with the brakes, but age and use will make that it can go anyday.

Rob

[deetes]

Spoke to SH, on the phone, this morning and he recomended changing the brake fluid to DOT 5.1, plus possibly fitting a new master cylinder. An interesting thing he mentioned regarding the master cylinder was that there were SEVEN!!!! different master cylinders used on the Wedges.

[350zwelgje]

Therefore a seal set can be a first option...

Rob