Is250 brake groan

peachy · April 28, 2017

Any is250 owners suffer brake groan when say inching forward at the lights or at a junction? Apparently it's quite normal for an automatic but I find mine to be quite loud.

Is this normal or could there be something more sinister going on?

Verbout · April 28, 2017

It's normal in most automatic cars I've driven, I like the noise, it amuses me and annoys the wife.

Wisty · April 28, 2017

Yep, both of mine have done this. Consequence of a gearbox trying to creep forward and the brakes trying to prevent it. Something's got to give

Rebecca · April 28, 2017

Same with my 250 and previous mercedes and bmw automatics I've owned.

I did point this out to toyota several weeks ago when I took my vehicle in for a service. It's perfectly normal I was told due to the automatic creep.

Obviously you don't get this on a manual as you will have your foot on the clutch.

madasahatter · April 29, 2017

8 hours ago, peachy said:

Any is250 owners suffer brake groan when say inching forward at the lights or at a junction? Apparently it's quite normal for an automatic but I find mine to be quite loud.

Is this normal or could there be something more sinister going on?

Also depends on pads and discs. I always use the foot brake at traffic lights, and any long standing que of traffic.

PCM · April 29, 2017

Calliper pins need re-greasing?

NemesisUK · April 29, 2017

Common with hybrids as the brakes get very little use normally. I've never experienced it in any other automatic I've driven except my AMG.

capese21 · April 29, 2017

My dealer said it was normal & offered no solution.

The pads imho get contaminated & glazed. I tried a few emergency stops but it didn't make any difference.

In desperation I fitted a set of cheap Mintex pads to the rear and the grunt is pretty much gone.

I have a set of more expensive Textar pads for the front. I am fairly certain Lexus OEM are made by Textar.

Ed

Verbout · April 29, 2017

12 minutes ago, capese21 said:

My dealer said it was normal & offered no solution.

The pads imho get contaminated & glazed. I tried a few emergency stops but it didn't make any difference.

In desperation I fitted a set of cheap Mintex pads to the rear and the grunt is pretty much gone.

I have a set of more expensive Textar pads for the front. I am fairly certain Lexus OEM are made by Textar.

Ed

I noticed my front discs were glazed and mottled when I did my pins the other month.

Never noticed it on my other cars.

Verbout · April 29, 2017

57% off at ECP. They show Brembos in stock.

£70 for a pair of front discs. :thinking:

Verbout · April 29, 2017

Just ordered for collection the last two in stock.

Verbout · April 29, 2017

STOP PRESS:

Ignore my last.....cheaper at Carparts4less.

peachy · April 29, 2017

Even with the original lexus pads fitted I still got brake groan but about 5 weeks ago I fitted new front pads and discs. brembo discs and pagid pads. The brake groan is definitely louder with this set up. The pins got well greased so it's not that. I'm guessing it's the pagid pads.

Now don't get me wrong the brakes work absolutely fine but it would be nice to eliminate the groan.

capese21 · April 29, 2017

8 minutes ago, peachy said:

Now don't get me wrong the brakes work absolutely fine but it would be nice to eliminate the groan.

Groan or grunt? Grunt is slow snails pace as the pads release off the disc. I will avoid brembo discs & Pagid pads as original discs with Mintex pads has largely solved it on my GS. I have had loads of automatic cars & none had brake grunt!! I cannot see why the Lexus suffers from it.

Ed

NemesisUK · April 29, 2017

Nothing to do with being automatic but all about being a hybrid?

Verbout · April 29, 2017

28 minutes ago, NemesisUK said:

Nothing to do with being automatic but all about being a hybrid?

My Lexus isn't a hybrid and the brakes groan. Only because I make them.

I think it's quite understandable as mentioned above. The car is trying to move forward and you're not fully on the brake. Friction causes heat and noise.

NemesisUK · April 29, 2017

Mine is a hybrid and I can see why the brakes groan, simply because they get so little use and there is the inevitable transfer of pad material onto the disc, which never gets hot enough to burn off. Stopping from speed simply engages the regenerative braking force. So, unless one requires an emergency stop the pad and disc don't come into play until virtually at rest.

None of my other cars has ever had groaning brakes certainly not just crawling in traffic where there is so little friction and no heat but any pad transfer was burnt off on the next stop from speed. The AMG suffered the same as my hybrid but that's because the brakes were rated for such high speed and repeated stops that pootling around town never got them warm. A couple of mega-stops sorted it out though

johnatg · April 29, 2017

I think all these explanations are too technical. It's simple - if you apply very light pressure to the brakes when there's a bit of drive from the engine/transmission, the pads vibrate and cause the noise. If you apply more brake pressure, the noise stops because the pads no longer vibrate (and the car doesn't move). If you apply less pressure the noise will also stop, again because the pads don't vibrate - but you might move forward more than you want.

Rebecca · April 29, 2017

Switching back to original lexus pads won't stop the brake grunt but will probably make it less audibel. As I've already said my lexus does the same, 2 other auto vehicles I've owned did the same. My mom has a bmw 330i that I often drive around and that also does the same.

I find if I apply light pressure to the brakes in stop start traffic etc etc it eliminates the grunt/groan or what ever you call it.

NemesisUK · April 29, 2017

As our experiences seem to differ even on the same vehicle types, it may well have a lot to do with how each modulates the brakes.

It's certainly not something I'm going to bother trying to eradicate by swapping pads and discs ....

Rebecca · April 29, 2017

It does not bother me to be honest. I've been told by toyota it's only to be expected on an auto vehicle and when I'm driving around with my favourite tunes blasting out the levinson I do not hear it anyway.

NemesisUK · April 29, 2017

Slightly off topic but I only found out recently that Mark Levinson is part of the Harman (as in Harmon Kardon) group. Small world ...

Rebecca · April 29, 2017

1 minute ago, NemesisUK said:

Slightly off topic but I only found out recently that Mark Levinson is part of the Harman (as in Harmon Kardon) group. Small world ...

Today I learn something new ☺

Britprius · April 29, 2017

JBL the premium Toyota sound system is also part of the Harman Kardon group. they also incorporate, Lexicon, AKG Acoustics, Infinity, and Sound Craft.

John.