Just bought a 2007 gen 2 from a dealership. Car was well maintained by its previous owner and taken to dealerships for its entire service life. Interior is very nice, though it's at 144k miles. I had both the combo meter and an alignment issue fixed within its complementary month warranty window. I will eventually need a new battery as the old one is getting long in the tooth. My question is: I occasionally can hear the sound of the brake booster's actuator = pump refilling vacuum. It sounds like someone is drilling something in the engine bay. It's not loud but I can certainly hear it. I don't have any codes and the pump doesn't run continuously. Only after braking do I hear it. My question is, is being able to hear it with the radio off imply that it is going bad? Should I be able to hear the thing run? I honestly don't remember hearing this before on my previous gen 2, but then it's been at least 6 years and my memory may indeed be faulty. Car runs well otherwise. Figure if it goes, i'll just be ready to slam down super hard on the brake and use B to get to the side of the road.
It does, after all, have to run now and then, to replenish the brake fluid pressure (the Prius does not use vacuum in the braking system). If you hear it run every few or every several times you use the brake (depending on things like how hard you brake), and you don't hear it running repeatedly by itself when you're not braking, then it's just doing what it's there for.
That's what I thought. It doesn't seem to be running often or every time I use the brakes but the noise with the radio off was definitely noticeable. Glad that I can relax and just drive the dang car. Cheers mate.
