Hi there I have recently purchased a 2007 Gen 2 Prius and sometimes it emits a very annoying squeak. It occurs when the car is stationary, with the brake pedal fully depressed. When inside the vehicle it seems to be coming from behind the glove box. When on the outside and facing the car it seems to be coming from below / behind the electric motor. I have made a recording of it with the noise in question being audible for a couple of seconds at 0:13, and then again at 0:22 until the end. It could be nothing I guess, but this is my first hybrid and I am not too sure what is perfectly normal and what is not. Any suggestions?
Do you mean the buzzing noise from brake pressure pump? It’s normal. It pressurizes brake pressure accumulator, where pressure can be taken to apply brakes when needed. You do get used to the sound.
The rattlesnake-like sound is the brake pump but you're probably referring to that rhythmic sound like a squirrel jumping on an old car or something. That's a weird one--I've never heard it. It doesn't sound normal. Is the climate control blower on? If so, there could be something interfering with its rotation? You could try removing the cabin air filter and inspecting. Open the lower front passenger glovebox, squeeze the back of the sides to release the holding pins from the dash, undo the little plastic strut on the R-side and let the glove box lower completely. Then locate the rectangular, white plastic panel with two latches, hold the latches open and pull the panel out toward you. Then you can inspect the blower (and change/clean the cabin filter). Oh, does it stop when you release the brake pedal? If so, it's probably not the blower motor. Maybe someone else knows...
I was referring to the 'squirrel' sound, not the buzzing sound. It sounds like a rotating part that rubs against something once per revolution. As soon as I take the foot off the brake pedal and the car starts to move, the noise goes away. Air con was off when I made the recording, but I think I will still remove the glove box and see if I can get a bit closer to the source of the noise.
I have done a bit of research and others describe it as honking, squeaking even barking ;] Have you clicked on the Vocaroo link in my original post?
Does it make this sound at different fan speeds? The fan never turns off completely. Try a higher fan speed.
Thanks for your responses guys. I could be wrong but what's in the attached TSB sounds very familiar to the problems I am experiencing.
I got lucky I guess as the car came with 3 month warranty, and the brake actuator a.k.a. brake booster actuator pump assembly has been replaced FOC by the dealership.
