Lexus GS350 F Sport front brake pad squeal

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7,539
Location
Los Gatos, CA
The Lexus GS350 F Sport cars use a Brembo style 4 piston fixed caliper. They are legendary for squealing.
There is a TSB that replaces the 2 part rotor with a single style and revised pad coumpound (I believe).

I took our '13 GS350 (77K, excellent condition) to a good local shop to diagnose a suspension clunk. There is another thread on that; the clunk source is not yet determined.
I do most of my own work; in this case I wanted to "put a little more meat on the bone" for them. So I asked them to service the transmission and check the brakes.
I gave them the Lexus filter strainer and 5 quart jug of Idemitsu WS equivalent ATF.

They replaced the rotors and pads. They used Textar pads, which are the supplier to Lexus. The pads cross reference to the original Lexus part number; not the TSB pads.
They did not squeak at first, but that didn't last long.
I pulled apart the passenger side to investigate. The squeal was clearly louder on the right side.
They used a thick black grease on the back of the pad and shim. Messy. None on the metal-to-metal surfaces.
They did not clean the keeper pin, spring or caliper.

I wiped off and cleaned the pad backing and shim, applied a good synthetic lube (Including the metal-to-metal areas) and reassembled the components.
I took it for a spin; the brakes felt great and the squeal was gone. It did come back after awhile, but was much more hushed.
So today I pulled both sides apart, throughly cleaned and lubed the components and reassembled.
Brakes feel great; no squeal for now. Let's see what happens.

If the noise returns to a level I can't live with, I will go purchase the revised Lexus pads and shims.
Our friend @The Critic recommended the Honda spec M77 paste to lube the pad backing. I will take his advice if I install the Lexus pads.
I should have stopped at the Acura dealer in town and picked some up, but I basically flaked. Sorry Michael...
Wish me luck! By the way, the Makita impact (thanks @Trav ) is flat out awesome-sauce!
 
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1,416
The black grease they used is fine and widely used in shops. I’ve used it, I’ve also used the purple grease, then the green grease. Doesn’t matter all of them work, yet none of them work. I’ve also used an orange paste (that’s supposed to stop brake squeal), that works too, and then it doesn’t.

I‘ve been told by some of these ^^ companies to apply their product to every single moving part of the brake system...back of pads, sides of pads, caliper pins, under the anti-rattle clips, on top of them, on the sides of them, on the caliper piston. By the time your done you’ve used almost the whole darn bottle of synthetic grease - which I suppose is exactly what those guys want - and then most of it washes away in three weeks and the noise is back. And then sometimes that goes away as everything breaks in.

I’ve gone to ”noise” classes too because once our supplier (AcDelco) pads, just couldn’t be quiet. So they taught, trained and explained how/why a brake pads makes noise. They ultimately said it was NOT the pad itself, but the back of the pads and when they rub and scrape against the caliper piston upon stopping movement. And thegrease and the shims manufacturers put on the back of the pads is the difference. Turns out that was BS too...because six months later AcDelco recalled their pads because of a manufacturing defect and apologized to us. But we since stopped using them anyway at that point.

So I guess what I’m trying to say is...it’s probably the pads. Doesn’t matter how “good” they are, they are all capable of manufacturing defects and a “bad batch”. Who really watches these people, aside from DOT specifications, outside of that, is anyone really watching how these brake pad material batches are being mixed/made? What goes into them on every batch, and how much? Maybe, I don’t know, but I’ll tell one thing I do know...noise with brake pads, hardware, rotors...is a problem that seems to be there on maybe 20% of the brake jobs we do. Comebacks because of noise...a little clip just doesn’t fit right, or a pad was just a little too big on the ears and didn’t fit into the bracket properly, or the caliper piston was just a little bit worn, or a pin was just a little bit corroded. And that’s the problem too...you’re replacing pads and rotors on a car with calipers and a hub and wheel bearing assembly that is 5-6 years old, with 70,000 plus miles on it. It could be almost anything.
 
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12,750
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Colorado Springs
That is strange for Textar. Textar is OE supplier for BMW and they are notorious for dusting, but never squealing. On E70 X5 35d they are OE pads, and they provided exceptional performance, a lot of dust, but never any noise. I am wondering if there is something specific to that assembly on Lexus?
 

JeffKeryk

Thread starter
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7,539
Location
Los Gatos, CA
That is strange for Textar. Textar is OE supplier for BMW and they are notorious for dusting, but never squealing. On E70 X5 35d they are OE pads, and they provided exceptional performance, a lot of dust, but never any noise. I am wondering if there is something specific to that assembly on Lexus?
All I can say is, the GS350 F Sport front brakes are notorious for squealing; this is well documented.
The non F Sport brakes do not suffer from this issue.
Owners have tried various brands (Akebono for sure) with poor results. Lexus put out a TSB.
Some have said the revised shims work with other pad brands.
My understanding is, the best solution is to use the revised Lexus components (Textar).
Perhaps the pad compound is similar to the non F Sport? Dunno...

We have all seen tons of brake dust on those beautiful Beemer wheels (a shame, IMO); my car has not had that problem.

Here is the stock pad from Lexus and then the pad the shop installed. Please excuse the mess...
The half shim is similar to the revised Lexus shim, based on what I have read.
You will notice the difference in the pad backing plate's bottom edge. This is also similar to the revised Lexus pad.

Lexus Textar.jpeg
Lexus Textar Scotty.jpeg
 
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3,923
Location
WI.
I'd always go OEM factory pads keeping in mind Toyota labels a 'factory' and 'aftermarket' version with different part numbers, later being ceramic.
 
Messages
12,750
Location
Colorado Springs
All I can say is, the GS350 F Sport front brakes are notorious for squealing; this is well documented.
The non F Sport brakes do not suffer from this issue.
Owners have tried various brands (Akebono for sure) with poor results. Lexus put out a TSB.
Some have said the revised shims work with other pad brands.
My understanding is, the best solution is to use the revised Lexus components (Textar).
Perhaps the pad compound is similar to the non F Sport? Dunno...

We have all seen tons of brake dust on those beautiful Beemer wheels (a shame, IMO); my car has not had that problem.

Here is the stock pad from Lexus and then the pad the shop installed. Please excuse the mess...
The half shim is similar to the revised Lexus shim, based on what I have read.
You will notice the difference in the pad backing plate's bottom edge. This is also similar to the revised Lexus pad.

View attachment 41566 View attachment 41568
No it's not. They outbreak anything similar on the road. BMW moved to ceramic compound on new BMW's, but brakes are more Lexus like.
 
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5,135
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Southeast
I have never had lasting luck with any of the greases. The orange/red goo which becomes like rubber once it cures has been good, if that’s where the issue is. The one thing which has helped every time has been to run the belt sander over the rotor as it spins to clean it up, on both sides.

my GS350 has new pads all around but the rear squeaks with the element3 pads, similarly to with whatever it came with. I didn’t want to pull the rotors at the time. It only squeals in reverse so I’m not particularly bothered enough to deal with it yet.

belt sander.....

m
 

JeffKeryk

Thread starter
Messages
7,539
Location
Los Gatos, CA
I have never had lasting luck with any of the greases. The orange/red goo which becomes like rubber once it cures has been good, if that’s where the issue is. The one thing which has helped every time has been to run the belt sander over the rotor as it spins to clean it up, on both sides.

my GS350 has new pads all around but the rear squeaks with the element3 pads, similarly to with whatever it came with. I didn’t want to pull the rotors at the time. It only squeals in reverse so I’m not particularly bothered enough to deal with it yet.

belt sander.....

m
I am guessing your car is not an F Sport. The non F Sports do not have the squealing issue.
I love those new Element 3 pads; they are not made for my car as far as I know.

Thanks for the grease information. Here is what I used. Blue in color.
PXL_20210115_232533567.jpg
 
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5,135
Location
Southeast
Correct, mine is a standard. The F-sport is another world. The standard brakes are massive as they are... the front rotors outweigh those on my f150. I can’t imagine ... and I think some of the propensity to squeak is because in regular driving, they are underused. Most squealing I know of occurs under light braking. If all of your braking is seen as “light braking” because they are jr. locomotive size, then it starts to make sense.

my father in law golfs and 1/3 of the guys up there drive lexuses. They have very commonly complained about “rotor warp” or pedal pulsation. My Lexus (used) had it, as did my tundra when I bought it. But their comments and repeated go-backs for resurfacing or replacement was common. adding to that, i replaced the front rotors on mine after using the pads for 6 months on the previous rotors. There was a definite change in brake friction with the new rotors. The pedal felt a touch firmer and the friction a touch lighter. I wonder if there’s a unique metallurgy in the oem rotors.

-m
 
Messages
12,750
Location
Colorado Springs
Correct, mine is a standard. The F-sport is another world. The standard brakes are massive as they are... the front rotors outweigh those on my f150. I can’t imagine ... and I think some of the propensity to squeak is because in regular driving, they are underused. Most squealing I know of occurs under light braking. If all of your braking is seen as “light braking” because they are jr. locomotive size, then it starts to make sense.

my father in law golfs and 1/3 of the guys up there drive lexuses. They have very commonly complained about “rotor warp” or pedal pulsation. My Lexus (used) had it, as did my tundra when I bought it. But their comments and repeated go-backs for resurfacing or replacement was common. adding to that, i replaced the front rotors on mine after using the pads for 6 months on the previous rotors. There was a definite change in brake friction with the new rotors. The pedal felt a touch firmer and the friction a touch lighter. I wonder if there’s a unique metallurgy in the oem rotors.

-m
I still think issue is compound in F sport as it is semi-metallic more aggressive one. Regular GS uses ceramic compound.
 

JeffKeryk

Thread starter
Messages
7,539
Location
Los Gatos, CA
I still think issue is compound in F sport as it is semi-metallic more aggressive one. Regular GS uses ceramic compound.
I think you are right. But so far the new pads are not making any noise. They feel great.
The only difference is the cleaning and lubrication that I did.

Time will tell, I guess.
 
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