My barking brakes

Any constant beeping when you're breaking like the thing beeping at you the whole time you're going down the road until something happens and it's not the accumulator coming to pressures what's happening.? Yeah it's time for an actuator there's no way around that or you just keep driving I drove for a year almost like this with the brakes of an old '60s Dodge truck with no booster and four-wheel drums lol car drove fine gas mileage was good breaking was terrible breaking is the least of my issues.

 

Iirc, changing the fluid can sometimes help, but it’s no guarantee

 

The usual way "air" bubbles get into a brake system is from somebody opening it up and doing work. If nobody has been doing that, then the bubbles you're hearing are probably nitrogen bubbles, escaped from a leaky accumulator. That causes all the same mischief as unbled air in a brake system, plus also causing the pump to run more often because of the loss of nitrogen from the accumulator (the same way the well pump runs more often in a house with a water well, if there's too little air in the house's pressure tank).

Going through the full bleed procedure will get the bubbles out and probably make your brakes quieter and safer for a time, but will not stop the problem coming back and the pump runs getting more and more frequent. Sooner or later you gotta replace that thing.

Regrettably, there is no old school brake bleeding of a gen 2. There are passages in the actuator closed off by valves that have to be opened to get all the air out; the bleed procedure using the ECU is what does that.

If you have trouble getting Techstream to work, there are other scan tools able to trigger the brake bleed procedures. There is a thread reviewing some choices; some strong recommendations emerged if you join it about here.

The "why worry? it'll just always brake like an old truck without power assist" line is an ok description of the way the system's fail-safe mode is designed to work—but there's a big unless involved, when you have enough unbled bubbles in the system.

With enough bubbles in there, if it goes into fail-safe it's going to stop just like an old truck with unbled brakes—meaning it keeps going.

So if it is barking like there are big bubbles in there, and you're not going to replace it right away, then definitely I would at least bleed the system ASAP, using Techstream or another scan tool that can do that.

 

Know when we had our loud continuous beep we had breaks I don't know about any barking never heard that and I have four of these things and three of them have had break actuators right here on the property replaced You don't do anything with the five lines if they cut them off at the factory or at the junkyard no matter you're just going to undo those lines that they cut off and throw them in the trash and you're going to unscrew yours in your car because you're not going to cut them because you want to use your car again they cut them at the junkyard so all the fluid stays in is the thinking. We've never had any barking we've had some funny business where the front brakes don't seem to be working in the backs do all the work when the thing is beeping like crazy and all that but it feels more like a Dodge truck without a brake booster on the firewall in four-wheel drum brakes If you know what that's about that'd be like 1964 you know I don't know we've never not had breaks and boy have we tried let me tell you I drove around with a broken actuator for about a year I'm very uneventful beeping all the time sometimes the beep would go away because the pressure would come up he'd be driving down the road smoking a cigarette and the beep would just come back on and you hadn't touch the brakes in 5 minutes and it would be the whole way oh well so this is interesting You replaced the brake actuator and 3 years later you're doing it again We haven't seen that either we've got a couple that are two two and a half years in so I guess we'll be looking to see what happens there I think the cars will hit 600k and maybe they'll be ready to retire I don't know

 

In gen 2 the master cylinder is an inexpensive, simple, separate part I'm not sure I've heard of anyone needing to change.

 

Which is kind of funny because that's what I call that thing that's mounted on the firewall that the brake pedal is connected to that moves fluid through a bore with a piston with a rubber seal around it like all master cylinders have moved brake fluid to squeeze the calipers and wheel cylinders at the wheel in. And the generation 2 it just moves the fluid from the master cylinder over to the business end of the deal which is the accumulator actuator and it does with computers and feedback the brake work other than your foot moving the pedal somewhat everything else is done by servo motor and pressure I guess. But in older Corollas and other Toyotas those master cylinders would wear out at about 100,000 150,000 a lot of times you'd pull the master cylinder and see fluid leaking out the back of it and that and the clutch master cylinder were a big problem back in the days you come out in your clutch would be empty It's the same thing as the brake master cylinder essentially It's just only running one circuit instead of two I have installed new seals and master cylinders board out master cylinders that couldn't be dealt with and put in larger pistons and seals like going from 3/4 to 7/8 or 1 in real common back in the day because back then those master cylinders might have cost a couple hundred bucks fast forward a few years in those master cylinders were like $39. Generally on the Prius you won't be touching the thing your pedals connected to on our model to generation two you'll be dealing with the business end behind the inverter with the five lines going to it and it looks like it's the business end of the brakes You couldn't mistake it for anything else. It's the thing that's humming and whirring all the time because it can't maintain pressure in that little black accumulator If you're good with a wrench sockets and tools you can change this part out and have it bled in about 2.2 hours so with that going on you can afford to put on a used one and have it not work and do it again or put on a used one and have it work for 3 years and do it again if you still have the car. The car is showing you that it's a worthy car if it's still with you after 3 years and the used part fails again who cares 2.2 hours and off you go maybe in that time you'll have the $1,400 for a real new one maybe not. But the car be that as it may like a Corolla is still one of the most reliable in the world.

 

You will easily manage this replacement at home and generally speaking your break should work like the old truck until you get them fixed but I guess I got to say if they don't they don't I haven't had one yet that's four of them to date that has ever put me in a position to go running through a stop sign longer stopping distances is discussed yes but nothing that's breathtaking pretty run of the mill and if you know it as in you've had the beeps and all this kind of thing going on then you will make the necessary adjustments now some people won't and those people shouldn't be doing anything out of the ordinary but then again there are some of us that can't help ourselves that doesn't mean you're going to go off the road and cause an accident I mean what are you kidding me You're slowing down so any accident you have is going to be real slow by somebody coming through and not seeing whatever the case may be It's going to be a sleeper whatever but some people you know they worried about everything in life that they possibly can because that's their nature. You have to respect everybody.