Pedal goes to floor after changing pads ???

[Bellingerp]

Hi - I've changed the front and rear pads and disks today ... I just wound the pistons back but did not disconnect anything ... Now the pedal is soft but goes to the floor after a while

Any ideas ...

Gonna bleed it but confused as to why I need to do this ?

Cheers

Pete

[Bellingerp]

Now well confused !!! Have bleed the brake .. Pedal is hard when not started but goes to floor when the engine is running ...

Is there anything I could of missed - could be a leaking seal but the brake were very good before I changed the pads just worn (about half) but the discs were shot

Any ideas ???

[3bars]

Sounds like air still in the system, or master cylinder seals damaged. Did you loosen the bleed valves on the callipers when pushing the pistons back?

[Bellingerp]

No ... I do regret not releasing the bleed nipple when pushing the pistons back ... I have to say the rear piston dust cover on one side was shot ... So gonna take it off and have a look tomorrow

Gonna invest in a pressurised bleeder too ... Will come in handy in the future

[JohnnyC]

Don't release the bleed nipple when pushing (or for the rears, winding) the pistons back.
Never understood why people do this.
Just take the cap off the brake fluid reservoir and make sure that isn't too full that it'd overflow.

[Bellingerp]

So - Checked the calipers - no fluid leaking...

My logical thought is that it is the master cylinder but on a 30,000 mile 2007 mini ?

Could it be the ABS unit ?

[Bellingerp]

Ok ... Maybe a little light...

The BMW MINI Manual (TIS) says the ABS unit needs to be placed in bleed mode ?

So off to the dealer

[JohnnyC]

What year & generation is your car?

[Bellingerp]

Its a 2007 R56 Mini Cooper S

[__kyle__]

Sounds to me like you just need to get it bled properly

[Bellingerp]

I have booked it into the BMW Mini dealer tomorrow

I explained to the service desk and they said it sounds odd ..????