Feel of New Brakes...Yikes!

Do what you want with your car..., i disagree with you 100%...

 

Pedal feel in Prius has absolutely nothing to do with condition of your pads or discs. most braking in normal conditions is done via regen, i've 32,000 miles on mine and still have 90% pads remaining.

If you drive carefully and conservatively you are less likely to do an emergency stop. i think that's a better tactic than making sure your pads are "bedded in".

 

I would rather use regen as much as possible. At 12,000+ miles, the factory grooves for the front rotors are still visible and for the rear rotors are as if never touched by the pads.

 

Prius brakes are a bit different to your normal car. The brake pedal is a brake by wire device so the feel has nothing to do with how the pads are (you are not directly connected to them). Most of the Prius braking is done by regen (using the electric generator to slow the car down and generate electricity at the same time). When you hit the brakes, the prius decides which of regen, friction, and engine braking to use.

This is a neat trick to do in a Prius...
Apply the brakes and let the car come to a stop. With your foot still on the brake pedal, push down. The pedal will depress more even though the brakes are full on!! On a normal car this would be bad news. Keep presing down and you will eventually engage hill start assist.

 

I have three Prii (2007, 2009 & 2010) and when all were driven off the dealer lot, the braking was better than any car I had previously owned! This obsession with bedding is truly unbelievable and certainly unnecesary. Perhaps, there is a problem with the brake system if you feel they are inadequate?

 

Last year we had to replace the rotors and pads on the RAV4 (under warranty) and they did work flawlessly at the first stop. Bedding in the brakes is what must be done on performance rotors with special pads but not anymore on cars like the Prius or other mass production cars. When I bought the Prius it had some rust on the rear rotors from sitting at the dealer over the last winter. I did one harder braking and after a little noise the rust was gone.

One thing that that could be possible with brandnew cars is the protection coating that sits on the rotors from production. This gets scraped off during braking when the car is sent to the dealer or the dealer cleans them with special brake cleaner. If this is not done the first brakings feel like there is an oil film on the rotors. A few harder brakings and all is back to normal.

Bedding in the brakes that hard like you described is not what I'd would do on a Prius !

 

Except at low speeds or during emergency stops, the pedal feel has nothing to do with the hydraulic brakes. The stroke simulator sits between the pedal and the master cylinder. That hard pedal was just the stroke simulator pushing back at you. Perhaps there is something in that mechanism that required a break-in. For the vast majority of owners, the hydraulic brakes require no attention over the life of the car. Just brake in neutral once a week to scrape the rust off.

 

Yeah. I wouldn't have done that either. My brakes felt just fine the day I picked the car up. I think all the OP did was put about 20,000 miles of wear on his brakes for pretty much no reason.

REV

 

Any new cars that I have bought in the past was taken on a nice trip through a variety of straight and curving roads in the country just to help break-in the car. Also to learn how it responds with driver input. Very enjoyable!

 

This sounds like how auto reviewers must drive the Prius to get mileage figures stooping to those of a common gas engine

 

No evidence suggests it must be done a Prius, nor would I subject my Prius to anything suggested by GM...

Your biggest worry is going to be keeping rust off your rotors because they aren't used in normal driving. In panic braking you get regen + pads. All you have managed to do is burn off a few thousand miles of brake usage and if they were smoking... yeah that's not good for anything down there. Almost everyone on here (except the mail carriers) will get 100k-150k or more out of their OEM brakes. With stunts like these, I don't think your will make it that far.

Just drive the car normally. It is nothing like your past GMs, this is actually built well. Do what Toyota says to do for your Toyota, and continue to do what GM says for your GM.

 

Aint THAT the truth. GM does pretty much EVERYTHING WRONG. If they suggest something, you can be pretty well assured that it would be unnecessary on a quality, well-built car.

REV

 

The stroke simulator is a piston pushing on a spring. There is no active component changing feedback pressure.

On the other hand, and this is a big other hand, the Gen III Prius is known for weird brake problems relating to feel. Gen III drivers are sometimes presented with hard brake pedal pressure when first starting up, which is a red flag that something is a little funny with the valving or brake controller. Gen II Prius do not exhibit this problem. Your break-in of the brakes may be related to this.

Tom

 

A couple early and inadvertent activations of the Brake Assist convinced me that my Prius stopped damn well without any breakin whatsoever.

 

I think it's fully debatable as to whether following the OP's procedure actually does any appreciable good.

But I'm also pretty convinced it probably does no harm.

In general taking a new vehicle someplace isolated and getting use to brake feel isn't a bad idea whether you believe you are seating brakes pads and rotors or not...

I think personally? I'd just drive like normal. Let time and regular braking to the "break in" for me...I don't believe Toyota would sell vehicles inwhich that involved of a procedure was needed for the average consumer to safely drive it off the lot...I think Toyota is pretty attentive to Brakes on The Prius...if a break in procedure was needed or recommended? It would be in the Owners Manual.

But tangible or placebo affect...the owner has a right to do it if they wish, and those saying he dammaged or pre-maturely wore down his brakes? Even going out and pushing them hard, I doubt is going to make a long term difference.

Now if he did this everyday?...but 1 morning for a few hours...I'm thinking his brakes are fine...

 

I'll test my brakes' ABS function about once a year in an empty rainy or snowy parking lot. Good practice.

 

I suppose the good news is that our cars are capable of tolerating and surviving from some levels of abuse.

 

Keep in mind, and I have a 2004 so the numbers might be different, but something like 75% of the braking is regen, meaning no use of the pads and discs at all. So if you stop slowly usually, you will have very little wear and tear on your pads and discs. Also depending on what car you are coming from you may have less weight transfer, since most of the weight in the Prius is down low, not up high like in a truck/Van/SUV.
Put it this way, I have just over 120,000 miles on mine, and the pads are still the original. While in my wife's Sienna, we had to replace the fronts at 40,000 miles. So really low use of the friction material in the Prius.