Brake “issue” before starting

[Eddie99173]

The Auris requires the brake pedal to be activated otherwise the automatic gear won’t work.

Used to feel rock solid till a few month ago. Instead of only a short stroke I could push pedal to the floor. The 2nd time same action: back to normal. Also while driving all ok.

The Toyota service checked the brake system during maintenance but found nothing.

Now 1/2 year later the problem - which had not been solved but only occurring sometimes - seems to revert more often. Have not checked in detail yet but but only thing I can think of would be the vacuum system leaking?
 

The car is not used all days but days without use don’t seem to have relation (time) to this issue

Not really a problem (yet) but I would very much like to understand it. And whether it is going to be potential dangerous in the future?

Any comments / suggestions appreciated!

[Cyker]

Generally, if it's soft when it shouldn't be, that more points to air in the brake lines. If it's hard when it shouldn't be, that'd more point to a vacuum leak.

[TonyHSD]

On hybrid any issue with the brakes will likely trigger a fault codes as they are electronically controlled. Any vacuum or fluid leaks etc.  Low 12v Battery can also cause issues as the system pressurise and depressurise itself every time drivers door is open or close and on each start up or shutdown of the car. If the car been checked and it’s ok then nothing to worry about. 

[Cyker]

Hah I didn't read the hybrid part  

Then that's trickier - The brake pedal feel is simulated in the hybrids so trying to diagnose it from feel alone is very difficult. I find the pedal in mine is only ever hard to push if it's in fail-safe mode or the vacuum reservoir has no vacuum left in it.

[Eddie99173]

@TonyHSD We don’t feel unsafe, it just amazes me. Bought the Auris in 2019 but the “issue” has only occurred since earlier this year.

And indeed as soon as started / driving everything is normal. And complete brake systems have been checked by dealer.

@Cyker The electronic systems in this car are very speciaal indeed. When we bought it the dealer already told us: don’t try to understand when the Auris switches between conventional, EV of both. Just trust it 🙂

So we do!