When the pump wears out from excessive run time, or it can't keep up with the worsening leak even running continuously, I'd bet your brakes will not function---at least not properly.
My 2012 Prius was doing this and the brake booster assembly eventually failed. Got about 4 warning lights and regenerative braking stopped working completely. The friction brakes did still work. Drove it to the nearby Toyota dealer and they covered the repair 100%, even with just over 100K miles on the car. Most impressive.
Is it really that "simple"? Or does it require a lot more pressure, while providing significantly reduced braking effect? And is the required pressure really natural for everyone, or just some? From my experience, it seems that some people who never experienced non-power-assist brakes will give up, believing the brakes have totally failed, without applying their full body weight to the pedal as is needed with some manual brakes.
Amazing it has a big leak constantly pumping and not throwing CEL or a RTOD on the dash with the accompanied BEEP. I would recommend if you feel any kind of wonky pedal feel/pressure like a stiff pedal with poor braking response be very careful there as the next step may be no brakes.
When it went out on me, I immediately felt the loss of regen braking and just compensated with the brake pedal. The car stopped fine. The dash lighting up like a Christmas tree was a good indicator something was wrong too.
Typically Prius braking forces are very strong and require minimal operator force. It can be dangerous because you lose power brakes and the additional braking provided by the regen system. So panic stops that would have been safe can become collisions. However there is usually no surprise because the warning lights normally go off prior to a given emergency braking situation. The warning requires several minutes of brake pumping operation before it goes to the limited failsafe mode. If your car is over ten years old or 150,000 miles, Toyota won't cover them at all. Before those limits it is covered.
There can be lots of reasons for the brake ECU to give up on regen braking. It will do so any time it's aware of a trouble code being set in the power management control ECU (because regen requires coordinating with that ECU). When that happens, the brake system itself still has its full capabilities, including an accumulator pumped to 2000-ish psi with brake fluid to assist you with. You notice when you're braking without regen, but it's not a big difference. Going into fail-safe mode where you only have the front brakes and no stash of 2000 psi fluid complementing your foot pressure, now that's a different ball of wax. You will notice that difference, and will have to work to stop the car.
If yours is below 10 years/150k miles, you may be still eligible to get a free replacement. https://static.nhtsa.gov/odi/tsbs/2019/MC-10164923-9999.pdf
I have scangauges This is a good point, which makes me think the car may have thrown the code triggering all the warning lights before the accumulator was completely gone, which is even better if true. I definitely didn’t feel a total hydraulic pressure loss.
You can get loss of regenerative braking, a dash full of warning lights, and manual braking without ABS caused by an intermittent OBD2 connection. Stop the car, refit the OBD2 and it clears right up. Probably not what you have though, if you are hearing the pump working intermittently and frequently.
Braking system, tires, and suspension are vitals. We must fix it or don't drive it. It is considered to be a criminal acts if we drive cars with problematic brakes, tires, or suspension that can endanger others. We can ignored catalytic converter code p0420, Just keep resetting it every 100 miles. But not for brake.
No, I’m at 15 years and 235,000 miles. I was planning on doing the $3k repair but my nephew was visiting and he noticed some other sound indicating the engine may not be long for this world. It’s been such a great car I don’t want to part with it! But being unable to do repairs myself I probably should move on. The Toyota salesman recommended not getting a 2023 due to massive changes that should be allowed to work out for 2-3 years, so pondering a 2022 if I can find one. They don’t seem to make the basic $25k model. Gotta get upgrades driving the price to $30-32k. I was out test driving other brands today but nothing has there visibility I’ve grown accustomed to in my 2007…. If it’s just the $3k brakes I’d repair, but if the engine is facing major repairs I think it’s a better car for the mechanically inclined. Wish I had a Chrystal ball…..
I would not worry about a 2023 Prius. The hybrid system, engines and brake boosters have been solid since 2016 models. The new one has better mpg and power. Battery guaranteed to 150,000 miles or ten years, the rest of the hybrid system is 100,000 miles or eight years. The real issue is getting one.
If you want cheaper alternative, just get corolla hybrid and it has 5th gen also with 1.8L but beefed up 135 HP instead of 122HP in 2019 corolla hybrid. The corolla has better safety sense 2 or 3 than 2016 Prius. Or you can buy Camry instead.
