Brake hold engaging clunk noise?

[Serban]

Hello hello,

I use hold function all the time and I'm wondering if anyone else gets a clunk noise when you come to full stop and release the foot off the brakes?

If I release slowly, it's not as bad and really slowly the sound goes away, so maybe it's nothing to worry about?

Sound is not there without the hold button function ON, as in, braking hard or using brake pedal as usual doesn't create this sound.

[Primus1]

Just starting to notice this on my cross, I’m sure it’s just started , it’s not a loud clunk but I’m sure it wasn’t there before…

[TonyHSD]

Can you record the clunky noise? 
Any clunking, squeaky noises from brakes may point toward brake service needed or suspension bushes cleaning. Can occur on recent cars too depending on driving conditions. Perhaps nothing to worry about. 
Check brake discs for rust or scoring., if any of the discs shows signs of that likely clunk comes from that corner. Usual suspects are slider pins on brake callipers. 

[Serban]

8 hours ago, TonyHSD said:

Can you record the clunky noise? 
Any clunking, squeaky noises from brakes may point toward brake service needed or suspension bushes cleaning. Can occur on recent cars too depending on driving conditions. Perhaps nothing to worry about. 
Check brake discs for rust or scoring., if any of the discs shows signs of that likely clunk comes from that corner. Usual suspects are slider pins on brake callipers. 

No squeaky noises. There could be rust that's not visible(car sat in dealership for a month or couple before purchasing?), the visible rust is on the edge of the discs, whatever rust develops on the surface it's cleaned by the pads and normal braking whilst driving. There is scoring, I've checked online what that means and apparently I've got that unfortunately. Perhaps in the rear, the outer edge is rusty both discs where pad does touch, but sound comes from the front anyway. I'd suspect nothing to worry at least until servicing in months time. Fingers crossed. 

[Cyker]

Weird; That shouldn't be possible as the brake hold just holds the brakes hydraulics - When you let go of the brake pedal, normally it releases hydraulic pressure, but when brake hold is active all it does is prevent that pressure being released - It doesn't engage anything.

The brake pedal isn't even connected to the brakes in the new cars unless it goes into fail-safe mode - It's brake-by-wire and all computer controlled with a hydraulic pump and vacuum booster!

I sometimes get a clunk when I press the accelerator to release the brake hold, but never when using it!

Can you record the sound?

The closest thing I've had to this is when I'm braking very very lightly or on a decline - MG2 tries to push against the brakes for a moment and it can 'give' a little when the brake hold activates under very light braking.

[Serban]

You've also got to keep in mind that my memory can fail me and improperly diagnose the issue. Maybe it's the actual braking system, hmmm. I'll try and record something the upcoming days if time allows.

[Derek.w]

Serban I was just wundering if the time before you used the brakes in reverse then next time going forward it gives a bang sound as the brakes are sticking in the sliders.

[Serban]

2 hours ago, Derek.w said:

Serban I was just wundering if the time before you used the brakes in reverse then next time going forward it gives a bang sound as the brakes are sticking in the sliders.

I don't think so. I'm not 100% sure what you're saying. Do you mean "reverse, stop, then drive forward"? And if that gives a bang sound? I don't think it does, but I'll check again.

[Serban]

13 hours ago, Derek.w said:

 

I don't know how to delete this.. anyway, see next reply 

[Serban]

So basically I've tried to drive a mile or 2, excuse my possible incoherent language as I'm driving, I can't multitask lol.

At the end, I'm pressing and releasing the brake pedal on and off to recreate the clunky noise I'm talking about as the "hold" function is engaged.

Also here pictures of before driving and after to get AN IDEA of right side(left side similar) discs condition..

Anything else that could be there, I'm not worried about, I'm also sensitive of hearing so you may not catch it yourself, I was just wondering if that clunk noise is something to be concerned about really..

It won't let me upload before driving R rear disc, but u can see after, it's 3rd photo.

[Serban]

Alsooo... I've changed my rear pads like a month ago because rear discs didn't look that well and when I've changed my tyres(rear) the mechanic said I should change pads ASAP or disc gets worse as they don't make full contact. I did, and mechanic who changed them said the same thing and they will be fine now and indeed they are, disc cleaned itself you can see in the picture or at least this is my understanding. The mechanic who changed the pads also mentioned that the factory pads were not fitted properly and that's why it didn't make good contact? Hopefully it's not the same case for front pads, I wouldn't be surprised if it was, BUT braking ability is strong and responsive, I can't see any issues whilst driving. 

[anchorman]

You could try resetting the maintenance mode.  This is a Lexus but I believe it’s the same…..

 

 

[Serban]

9 minutes ago, anchorman said:

You could try resetting the maintenance mode.  This is a Lexus but I believe it’s the same…..

 

 

What is this supposed to achieve? 

[anchorman]

6 hours ago, Serban said:

What is this supposed to achieve? 

What do you think…..

[Serban]

17 hours ago, anchorman said:

What do you think…..

Turns it into a lexus

[Cyker]

Can't really tell from the video TBH; Pulled-out-of-my-butt theory: Maybe it's just the sound of the pedal releasing with less damping? As I said it's brake by wire, so maybe when the brake hold is active, the piston doesn't follow the pedal when you release it, so it isn't damped as much when it hits the stops??

It's subtle and hard to hear enough I don't think it's anything to worry about tho'.

I use the brake hold all the time because the EPB is really slow compared to a normal handbrake, N is not recommended for hybrids, and I don't like using P unless I'm going to e stopped for a significant time. I've had the car for nearly 3 years now doing that with no issue, so I'm sure it's fine!

[anchorman]

9 hours ago, Serban said:

Turns it into a lexus

Sounds like you don’t need any help with your brake noise.

[Serban]

2 hours ago, anchorman said:

Sounds like you don’t need any help with your brake noise.

I've reset it, thank you.