hi,
i am french and forums are very poors in france for infiniti cars.
i have vibrations in brakes at high speed.
i want to know if it is a current problem on QX70 or others infiniti cars.
can you help me
Dany

Welcome. You probably have warped rotors if it only happens under braking. Either have them re-surfaced or change the rotors (and pads). In the US, you can get a set of 4 rotors and 4 sets of pads for under $200 USD for a Q70.

Also, moving this to the correct forum.

j'ai du mal a y croire car je ne freine jamais tres fort.

I agree withe Ilya, This is a symptom of warped rotors, or inconsistent thickness of rotors. Your rotors must have worn irregularly, somehow. Perhaps the steel was softer in places, and a bit harder in others? It happens. You can resurface them to make them uniform again, or else just replace the rotors with new ones. They're pretty inexpensive in USA, so we usually just replace them, which fixes the problem instantly.

Driving through puddles with hot brake rotors can easily warp the rotors as well. Hard braking is not the only cause. I would have the rotors resurfaced or replaced. It's not a difficult procedure if you have any mechanical skills you could do it yourself.

petites indications:
1ere chose: j'ai fait remplacer le liquide de frein récemment parce qu'il était ancien.
2eme chose : pendant le confinement du covid, le véhicule n'a pas roulé pendant 2 mois et les disques ont rouillé.
je ne sais pas si cela a pu avoir un impact

Shouldn't impact anything but good to keep up with fluids. I'd focus on brake rotors. Let us know how it goes.

Hello,

Is it akabono brakes? If it is this is how to solve it. Change, discs, pads, shims and spiders. and ALSO change lock sprints and bolts to the calipers.
Get out and drive and enjoy! The akebono lock pins for the pads through the calipers have poor quality. The surface rust and crack and dont let the pads flex in the way they should so the discs get warped and You get vibrations.

i dont understand very well, can you explain ?

i have changed rotors and problem is the same.............

Something new: it vibrates also when I brake with the foot brake (manual), which, if I am not mistaken, is on the rear wheels, which pushes the front discs apart, the rear discs have already been changed as a preventive measure. it would therefore be more of a transmission problem. What do you think ?

Driveshaft maybe, check your U-joints. They change inertia when you transition from throttle to brake.

yes, it's a good idea. is it possible to have plans/pictures of mecanic implantation ?

seen with my mechanic this morning: abnormally large play on the central support bearing of the transmission shaft. FYI, it vibrates by activating only the rear brake, so I have a doubt that it is the front discs, as you say. and the rear discs are new.