Intermittent Brake Failure

[Series9]

I was presented this evening with a 986 which may have an IMS failure, but this new customer came to me because she had 'broken up' (her words) with her last Porsche mechanic over a brake issue on the same car.

Apparently it's happened twice. The pedal goes to the floor, she swerves to miss traffic, uses the parking brake to stop and then, after a few minutes, the brakes return to normal.

The master cylinder was replaced before it happened a second time. The two events were weeks apart and the computer can find no faults or stored codes in the ABS computer.

Anyone seen this?

[ABQautoxer]

The pedal going to the floor is the weird part. That suggests air in the lines. I would have guessed ABS ice mode if she said the pedal was firm but no matter how hard she pushed it only partially slowed down.

[Markus Vancouver 01]

Good Evening,
Markus here - new member.
Did you ever resolve this issue?
Is a little bit of pedal travel normal in the Boxster / Cayman?
My mechanic just replaced my master brake cylinder - oem.
Bled 5 litres of top quality fluid.
He's not happy with the pedal travel.
Any thoughts?
What is everyones experience?
Thx