GR Yaris Highway braking problem

[MarkoS]

I've been driving on the highway at around 140km/h with 0c temp and rain.
At first braking after some minutes, for a second or two there was almost no deceleration, then car started braking unevenly, pulling to the left.
Few repeats and the issue was gone, braking was back to normal.
In the city at low speeds all is good.
I have recently had fluid changed to some Motul racing one, running Ti shims, Goodridge braided lines, RS3 vents with drilled anchor plates.
Could I have "overcooled" the brakes for winter time?

 

[Onehp]

Usually this is the recipe for 'salt goo' making a film on the disks, assuming your roads are being salted a lot like here. Happens to me maybe once every two years when it's bad. Maybe your mods help the 'salt goo application?'

What to do? Another application for my beloved left foot braking

However if the problem remains in other weather circumstances, you definitely need to check your brakes!

Edit: otherwise no such thing as overcooling brakes, unless your pads really don't work without heat in them...

 

[Goffy]

I have had the same problem in heavy rain, while making "good progress" on a long bypassed former A road here in Devon.
No actual flooding but plenty of rivulets and puddles, as I braked on approach to one of the junctions where the old and new roads intersect, I was rewarded by NOTHING for a second or two!

No question of salt or grit being involved, just rain water. It's happened much more mildly since too!

I now make a practise of a little left foot braking in these conditions to keep things dry for when I need to stop!

 

[Dan_D]

I have this every time I've washed the car. Go a drive straight after and it takes a few times before the brakes bite properly again. I'd put it down to water sitting in the grooves on the front discs. Never had the same issue driving in wet weather though.