Sticky brakes during hot days

[TheGuyWithStickyBrakes]

Hello everyone,

First of all, sorry if my English isn't perfect, I'm french :D

I acquired in 2018 an Aveo, the exact spec is 1.3 VCDi 95ch Start&Stop LTZ (5CV) 2012, it had 60 000 km.

I reach to this forum because since I bought it i have been struggling with a braking issue.

Only during hot days (when temp is above 20-25°C or when the sun is hitting hard on the car) I have a recurring issue : the brake pedal is sticking when I press it. I have to manually get it back up with my foot or else it keeps sticking and breaking. It's not a big problem for small trips but I can't risk it on the highway.

It already cost me a few unwanted breakdowns on the highway during family trips, and the mechanics here in France seem to have no ideas what could lead to this issue. As I keep driving on the highway it keeps getting more and more stuck and finally the car vibrates a lot and keeps breaking by itself, the front brakes are completely stuck, smoking, and the pedal does not get up. I have to wait a few hours to let it cool down if I want to unstuck them.

They tried to change the brake pads, the discs, the brake fluid, but nothing worked and I am stuck with a car that I can't use almost half of the year. Good thing I work from home and in Brittany where the weather is not as hot as in Provence :)

I was wondering if maybe there was a known issue on the Aveo regarding this ? Mechanics here have no clue and not very cooperative. They probably don't know a lot about this car (I have also a code 89 when I start, nobody was able to make it disappear, it goes away when I press menu though).

Hopefully someone will be able to help me, my car is otherwise great and only has 95 000 km !

Thanks a lot for anyone that helps me

PS : Also I tried to search for it on some forums but I saw nothing, my fellow french people are not able to help me also :(

[guitardoc64]

That sounds to me to be a bad master cylinder.

[Eg.h2o]

Bad master,or possibly brake booster