Master Brake Cylinder Failure

This is new but considering the cost, this sounds like the assembly that holds all of the valves. If you can, perhaps ask for the failed part?

Used parts from warranty work are not always given to the owner but asking is OK. If nothing else, ask for the part number and see if you can make photos of the part.

Bob Wilson

 

Sounds like an awful lot to me (my only BMC failure experience was on my Mom's Saab and that was about US$1K--maybe more complex due to the hybrid features?) Sounds like Bob's advice is good--if they won't give you (access to) the part, you could at least call around to other dealers asking quotes for the exact work completed, and maybe compare w/ same from an independent shop.

At least it was under warranty! Good luck.
~T

 

Given that the car is essentially brand new and the failure is significant
-- not catastrophic in that there was no accident/collision -- I would
expect that Toyota would want to inspect/tear-down the master brake
cylinder for quality control purposes.

So, is there really any chance of getting the part?

 

Close to zero chance. The OP is not paying for the part, so the dealer will either discard it or else return to Toyota (if Toyota cares).

My guess is that the failed part is the brake actuator assembly.

 

Agreed.

Many manufacturers require dealers to keep parts replaced under warranty for a certain period of time, to allow the manufacturer to audit warranty repair work.

 

Toyota will want the part.

 

DOesnt autozone sell one for like $40 bux?

 

The Brake Master Cylinder is the component that turns your pressure on the brake pedal to hydraulic pressure in two pipes. On a conventional car (no Electronic Brake-force Distribution) that pressure then pushes the piston in the wheel cylinder, which presses the pad against the disc/drum, with each brake line handling two wheel cylinders.

In the Prius the lines normally go to a pressure sensor and a 'stroke simulator', a cylinder in which a piston simply pushes against some springs, to provide the feel of braking. There's a unit - the actuator - full of hydraulic valves that control the flow of brake fluid from a high-pressure reservoir (accumulator) to the wheel cylinders, and pressure sensors that measure what's going on.

The third part is the Skid Control ECU which controls the valves according to the pressure sensors measuring the driver's input and the sensors measuring the brake force applied.

Champion ToyotaWorld doesn't yet have parts listings for the 2010 Prius, but for a 2009 Prius the costs are: master cylinder $114.56, actuator (listed as 'modulator valve') $1,412.03, ECU (listed as 'control module' under 'stability control') $1,112.05. Those are discount prices, the MSRP is considerably more.

I don't have a 2010 manual, but for Gen 2 it was necessary to remove the inverter to replace the actuator. TSB BR001-07 (Brake Actuator Noise) gives a time of 4.4 hours to replace the actuator. On the 2010 car the inverter (Power Control Unit) is smaller and further toward the front of the car so it may now be out of the way. You also had to remove the inverter to replace the master cylinder.

 

But the price is in CDN so the $6gs could be on the low side
Parts fault, at times, and it is no one fault, it getting fix , you have loaner so all is good

 

Regardless, that sounds like a ridiculous price for that part, and I have to say this sets up a significant doubt in my mind about the longer term cost efficiency of owning a Prius. Hopefully, this is just one small data point and not part of a larger trend toward the parts manufacturers taking advantage of the complexity of this car to gouge customers.
Here's something else I've been thinking about - if parts are that expensive, what happens when one of these has a fairly serious front end collision? All those cooling radiators and the complex electronics, etc. I can imagine the insurance companies may well be totaling these cars for damage that, in a more common vehicle, would be easily covered within the insurance envelope.
Worrisome, to say the least. We hit a lot of deer down this way, and I can imagine such a collision doing damage to the tune of at least 10-12K, which would pretty much total a Prius that wasn't right out of the showroom...

 

Prius have proven very cost effective over the long term. You shouldn't read too much into a major warranty replacement. In this sort of situation Toyota will often replace an entire assembly to make sure the job is done quickly and without complications. For a non-warranty repair you often can replace or repair only a subsection, or use a rebuilt or salvaged part.

Tom

 

OK, Tom, thanks, that's somewhat reassuring. I will search through here on accident threads to see how Priuses fare in the "totaled out" department. When I put my aftermarket horns in, I could not help but notice that engine compartment has a lot of pricey-looking apparatus up front...

 

That it does. It's one of the paradoxes of high tech electronics: it's not likely to fail, but when it does, it can be expensive. The average cost of ownership is very low, but if you are one of the unlucky ones, a repair can be expensive. It's like being hit with a piece of falling space junk: it's not likely to happen, but if your the one that gets hit, you are totally screwed.

Tom

 

Adding to Tom's comment:

In the USA we lose about 3% of all vehicles per year. A substantial number wind up with a significant number of usable parts that can repair other Prius. For example, AutoBeYours has been in business for years rebuilding salvaged NHW20s. The irony is if someone wanted to buy a plug-in Prius, AutoBeYours has been selling them for at least a year if not longer.

One other aspect are the growing number of 'Do It Yourself' folks whose curiosity leads them to figuring out how these vehicles work. Often we learn more from what fails than from parts that never get 'opened up.'

Bob Wilson

 

That price is totally ridiculous.... $6,000 is a quarter of the cars total new cost. For a brake master cylinder? If the cost of replacements part is that high, who would take a chance on buying such a car with a 3 year, 36,000 mile warranty?

 

I am also concerned about the cost of such a part post warranty, but happy to hear the warning system works- for your sake and all who own a gen III.

 

I JUST had this fixed in my car.

I got the car on the 30th of May, and it was in the shop 6 days later.

It has been there since...until today.

They had a guy fly in to fix it and also 3 guys from Toyota corporate to come and see it.

I didnt have any alarms go off, just a loud creaking sound from the brake pedal when depressed or released.

 

Hopefully everyone has GAP insurance.