2010 Prius II Question Brake Test

how many miles on her?

is this a prius service manual test, or just a generic brake test? the reason i ask is that prius brakes are a bit different than normal.

 

Conventional cars with power brakes get their power assist from a big old chamber with the air sucked out, and you can usually use up that assist within two or three pedal strokes, the "pedal getting harder" effect you're thinking of.

Prius doesn't do it that way, but with a gas-filled canister kept pumped up with brake fluid to a very high pressure. You can use that up too, it just takes more like twenty to forty pedal strokes, not two or three.

You're not really going to feel a gradual increase in pedal effort; you'll get your twenty or thirty strokes that feel about the same, and the next one's like you stomped on a rock.

That's all if you prevent the pump from just coming on and replacing the pressure you're using up. If you hear the pump start (a little buzzy noise under the hood), you might not reach the pressure-depleted point as soon as you expect.

You can stroke the pedal fast enough to beat the pump at its own game, and so still eventually use up the assist even with the pump running. You will get brake warning lights on the dash and a high-pitched alarm if you do this.

I'm not sure how much interesting information you really get from a test like this.

 

i would change the fluid based on your maintenance schedule. go by years or miles, whichever comes first.

also not the rough duty service, or whatever terminology they use. the intervals are shorter if your driving in severe conditions.

 

Toyota USA has not recommendation for brake fluid change. Toyota Canada recommends tri-yearly or 48K kms (30K miles approx), whichever comes first.

I think it's a good idea to change it periodically regardless which side of the 49th parallel you're on. I wouldn't bother with testing, just pick an interval and do it.

I've had the dealership do it once, and did it myself a couple of times now. If you're interested in DIY'ing it, watch @NutzAboutBolts video on the subject: there's a thread pinned in third gen maintenance forum (at the top). Also, I've attached some Repair Manual info, the method without Techstream (Toyota proprietary software).

If the dealership's offering to do it, and that's your preference, I would go for it. How much are they asking? It should only be around $100; if it's much more than that I would shop around, to other dealerships. There is a very specific method to doing, so I'd be careful about lietting other shops just hop in.

In particular, the car needs to be in "invalid mode". This not hard to do, but if the shop doesn't know about it, you can end up with problems.

FWIW, I did this a few weeks back, takes about an hour, and my wife helped, pushing the brake pedal. I used very rudimentary tools, nothing fancy.

 

Try pumping the brakes more than ten times, it will build up and check your brake reservoir level right afterwards.