Brake Pedal goes to floor...

[b0rk]

ATE used to, but blue dye was banned about a decade ago.

ATE super blue (now typ 200) is no longer blue, but now colourless changing to yellow as it absorbs water like all other DOT4 fluids.

Edited by b0rk on Tuesday 2nd April 02:39

[E-bmw]

TREMAiNE said:

E-bmw said:

Basically, it sounds like you need to get the brakes looked at from end to end by somebody competent to do so.

Brakes don't really just "stop working" in use.

All calipers need checking out, the discs & pads need to be checked, and the system needs to be bled properly from end to end.

The situation you describe could be a number of related issues & systematically diagnosing them is your only answer.

With all due respect, this is an incredibly patronising comment.
We've had this track car for years, my friend who I do this with has refurbished the brakes on multiple occasions, we've bled the system on multiple occasions over the years.

We are aware that there are a number of issues that could cause the problem, and we have been trying different solutions as to what it might be, hence the reason for this post - asking for some advice of what else we could look at to see if we can sort ourselves.

Your comment is of absolutely no value, relevance or help to the question asked.

YOU may see it as an "incredibly patronising statement", however look at it from my viewpoint.

I do not know you or your abilities mechanically.

You make a statement that the pedal goes to the floor, clearly indicating that there is air in the system or the master is doing nothing and yet you claim to have checked everything and bled repeatedly.

If you have bled & checked the brakes and understood what you were doing you would have found the issue easily, clearly (to me) indicating that you don't understand brakes.

Hence why I said you need to get someone who is competent to look at them as brakes are kind of quite critical.

Don't worry, I won't bother trying to help again for fear of being patronising again.

[MustangGT]

Another maybe, is has the fluid overheated and lost its workability?

[Maxdecel]

MustangGT said:

Another maybe, is has the fluid overheated and lost its workability?

IME The pedal always returns when cooling, besides:-

TREMAiNE said:

Anyway... we replaced the master cylinder and have bled the brakes but the pedal is still going to the floor. Thanks.

[stevieturbo]

TwinKam said:

I think you may have air trapped in the ABS unit. We try our damnedest not to allow this to happen as it can be a bh to get out, but sometimes eg replacing the master cyl it is inevitable.
You can bleed it 'electronically' via the OBD if you have a compatible scan tool, but you could try to manually bleed it at each of the four line-out unions on thd ABS unit, before bleeding the four corners again.

reverse bleeding is ideal for this.

Just change the master, minimal fluid loss in the actual system, and then push fluid back in via each bleed nipple

The pipes and ABS system should never be dry in this process.

[richhead]

i have had a new mastercylinder be faulty before, was scratching my head for ages before i replaced it again and all good, turns out there was a faulty batch, oh and defiantly dont clamp braided hoses.