Brake pedal going to the floor?

[bluetyre24]

I have a 2008 Seat Ibiza, and the brake pedal sometimes maybe once every couple of days goes to the floor and then brakes hard, so they dont fail or brake sluggish, ive had the discs and pads checked and rear shoes taken apart and checked I've had the brake master cylinder replaced, the brake servo checked, and all the system bled, and it still does it, any ideas on what it could be? thanks

[E36Dan]

bluetyre24 said:

any ideas on what it could be?

Dangerous, by the sounds of things.

Possible ABS fault? Any codes? My Volvo gets a funny pedal sometimes when the ABS has a moment. Never goes to the floor though. That would indicate a hydraulic problem to me.

Frayed rubber brake hoses perhaps?

Brakes are serious, it sounds like you've already had it in at a garage, maybe it's time to try another...

[Gary29]

Sounds like you've checked everything it could be.

I'd say you need to check more thoroughly or let someone else who is an expert take a look. Guessing SEAT is a car where the master cylinder is on the nearside and connected via a series of rods like a lot of Euro boxes designed to be LHD

[mcdjl]

Might be a dodgy seal somewhere.

[trickywoo]

E36Dan said:

Frayed rubber brake hoses perhaps?

Brakes are serious, it sounds like you've already had it in at a garage, maybe it's time to try another...

I was going to guess at failed hoses too. Perhaps internally so not obvious on a visual inspection.

Also agree on going to another mechanic.

[Pdelamare]

Replace your master cylinder, 99% probability of it being that if you're sure there's no air in the system.

[trickywoo]

Pdelamare said:

Replace your master cylinder, 99% probability of it being that if you're sure there's no air in the system.

bluetyre24 said:

I've had the brake master cylinder replaced

Either not done right or its something in your other 1%.

[Mr2Mike]

Could be pad knock off caused by a duff wheel bearing. Does it have discs or drums at the back?

[GreenV8S]

bluetyre24 said:

sometimes maybe once every couple of days goes to the floor and then brakes hard

I guess you mean the pedal has to be pumped once or twice before you get an resistance.

Any pattern to when this happens i.e. is it when you haven't used the brakes for a long time while driving, or first application when the vehicle has been parked for a long time, etc?

If the problem happens quickly (brakes fine for one corner and the pedal goes to the floor for the next) that would make me think you have a serious problem which could lead to total brake failure at any time. But if it comes in gradually (pedal feels a bit long the first time after you have thrown the car round a roundabout) it might be a less serious problem like pad knockback.