Brake pedal to the floor

[HDPete]

I have noticed today that, although the brakes work Ok, the pedal goes to the floor. Is this normal on ceramics on a 2018 Vanquish S or does it need looking at? Fluid levels all seem fine.

[steveatesh]

Be fine, what could possibly go wrong ! 😂

Needs looking at for definite.

[vernierMike]

Sounds hydraulic, not carbon related. But yes, get checked before....

[telum01]

Most likely hydraulic. A huge loss in brake pedal pressure is unrelated to the rotor type.
It could be an open line (look for leaking brake fluid) or a caliper piston seal, or a problem with your master cylinder.

[RichB]

HDPete said:

I have noticed today that, although the brakes work Ok, the pedal goes to the floor...

Pete, the brakes are not working ok if you suddenly need more retardation and the pedal is already on the floor you are stuffed. Get it looked at before you drive it again. Seriously...

[HDPete]

Yep. Thanks - agreed.

It’s being recovered to the dealer. I suspect I boiled the fluid on a recent track day, but if that’s the case I’m surprised that they don’t spec a higher boiling point fluid.

[RichB]

HDPete said:

...I suspect I boiled the fluid on a recent track day, but if that’s the case I’m surprised that they don’t spec a higher boiling point fluid.

Quite possibly. Worth asking the dealer what fluid type they use. I use DOT 5.1 in my Griffith and that get thrashed on track.

[8Tech]

HDPete said:

Yep. Thanks - agreed.

It’s being recovered to the dealer. I suspect I boiled the fluid on a recent track day, but if that’s the case I’m surprised that they don’t spec a higher boiling point fluid.

You should not have boiled the fluid with CC discs, thats the whole idea of them, they cool quickly.

If you did boil the fluid, then there must be a lot of water contamination in the fluid which drastically reduces the boiling point. Can you confirm 100% that brake fluid changes have been done to schedule, whether you have paid for it or not? Its then the water vapour boiling at just 150C (at just 5% contamination) rather than the 230+C or so required to boil pure brake fluid.

A job easily charged for without doing unfortunately.

[HDPete]

It's brand new with 1,500 miles on the clock, so it's never been changed.

The fluid is a very light straw colour and the levels are fine.

[vernierMike]

Any boiled fluid will only be evident at the calliper when you bleed it. Different car, but got total brake failure in the paddock (thank goodness!) where the pedal went straight to the floor, no resistance. After an hour, pedal restored and a bit spongy but not to the floor.... so drove home.

When I bled the system a few days later (great things, Eazibleeds!) the fluid was full of micro-bubbles and white looking for the first 20cc or so then straw clear.

Good point ref life, moisture absorbance and boiling point. I use 5.1 in my racing bikes with 6 month changes.

So could be pre-boiled fluid but I don't think it'd account for such a dramatic pedal action. Defo get them looked at soonest, and let us all know!