Squeak / Bark Noise After Shut Down

[OldSkoO1]

I've noticed my gen 3 prius makes a very strange bark / squeak type sound around 1 maybe 2 minutes after the engine has stopped or been switched off. I naturally though it was a pump or actuator working. I didn't think much of it until today.

I was turning into a blind side road only to see a garbage collection truck coming towards me, being a 1 lane street I brake quite hard and noticed this strange noise again the first time it happened when power was on and then I reversed.

Has anyone heard of this and what it might be? I've braked harder before during power on and not noticed it. In general everything else seems fine with the car apart from this really strange noise after shut down which has now happened as I braked.

People have commented on the noise so it isn't me being hypersensitive

[kithmo]

I used to get this, very occasionally, with my + but only on start up. It sounded like the noise you get when you release the brakes very slightly when sat in traffic, the groaning of the pads. I thought it might be something to do with the brake system pressurizing and maybe moving the pads slightly. I was going to mention it when it went in for the major service last month, but I thought because it only happened on start up first thing after being stood and I couldn't reproduce it, I'd wait for it to happen more frequently. Funny thing is, it hasn't done it since the service, so maybe they did something that moved the pads to a different position.

[Ten Ninety]

My Prius and my wife's Auris HSD both make a wide range of noises after shutdown. Clunks, shunts, buzzes, whirs and everything in between. All normal. Sometimes I've heard similar noises when stopped in traffic (in Ready mode) but I can't recall hearing similar when braking.

What I do often hear when braking in the Prius is a loud creaking noise when pulling up to a stop; it's a typical disk/pad noise and occurs just before stopping at the point where the disks take over from the re-gen. It's done it since I got it; it stops for a while after a service and then comes back. I put it down to lack of use of the traditional brakes as I stay in the re-gen zone almost all the time, emergencies excepted. The Auris doesn't make the same noise, but then that gets driven by my wife who tends to brake a lot later and a lot harder than I do.

[Grumpy Cabbie]

Wonder if you braked so sharply the emergency brake assist took over? That will really, and I mean really brake hard for you in emergency situations with or without engaging abs. I've only had it engage about 3 times and you'll know about it. I think it might have make that weird noise after.

If there are no warning lights on and the car stops ok and doesn't make weird noises every time you brake, then chances are it's fine.

[IanIanIanIan]

My PiP blows a rich raspberry sometimes some 3-4 minutes after parking. I have been told it is the brake pressurisation system venting through a relief valve and totally normal if embarrassing.

I can't see how a hydraulic system depressurising can release gas but I understand the fuel system is pressurised whilst in use. It makes more sense that it is that relaxing and venting. Who knows?

[Grumpy Cabbie]

They all do it. Known as the Prius !Removed! or burp.

Scares the hell out of you if you forget and start washing the car or even hours later when you've washed the car and start to polish it.

It is something to do with it releasing pressure in the brakes, it's an electric compressor pump which you'll hear charge up when you first get into it in the morning. I wonder if it's not healthy to store the pressure long term? Or at least cause extra wear and tear.

Dunno, but it's normal.

[OldSkoO1]

Yes I think that's it.... A !Removed! once the car has been switched off. It seems to do it every time I stop and park up after a minute or 2.

It through me because it happened after breaking quite suddenly.

However I did break harder the other day which was much more ferocious and it didn't make the sound then.

When I did brake and the noise came I'm pretty sure I was on ev. And yes I do hear it make a whine type noise once I unlock it and open the drivers door but I figured this was normal.

[Alan1572]

Mine makes a weird noise when I apply brake pressure

[OldSkoO1]

Ok it certainly isn't a squeak

It certainly is a !Removed! noise. Very odd indeed!!!

[Mkuk0]

Mine makes a weird noise when I apply brake pressure

Sounds like squeaky chickens to me that does!

[Parts-King]

They all do it. Known as the Prius !Removed! or burp.

Excuse you :D: