First of all i apologize for my english but I couldn't find any answers in my country. I guess you've already discussed this issue but i do not know how to describe the symptoms briefly in the search box.
I've got a FEH 07 and every time I use the brakes it feeks like something is pushing the car from behind right before it stops. I can't say it's something critical but i do not know what should i expect of it in future. The brakes are also quite weak. It's easy to get used to it but I do not know if I'd be abje to brake in case of emergency.
Do anyone of you experience smth like that? My wife is now driving the car and I do not want to be worrying each time she gets to the wheel.
BTW it's not my first hybrid. 3+ years of prius NHW20 but i never felt anything like that before.

 

Without knowing how many miles(km) you have on the vehicle or it's history, it really hard to diagnose, however, from what you describe, it sounds like you have air or moisture in the brake system. I would bleed the brake system.

 

Thaks for the help. it's 100k miles now and everytime it happens "slippery road' icon appears. but the road is absolutely dry. what can it be?
thanks in advance

 

Sounds like a cracked/broken tone ring. See this thread for more information.