Do All 4GS Models Use The Exact Same Front Caliper? We may finally have the answer...

There seems to be confusion about the front calipers for the various GS 350 models, including the GS 450h. The confusion is whether the F-Sport RWD uses a different caliper than the other 4GS RWD models. Also, whether the Lexus marketing literature and website is correct that only the F-Sport RWD model uses 4-piston front calipers. The following information has been gathered in order to answer those questions!

Here is an ADVICS #47750-22460 OE Left Front 4-Piston Caliper off a GS 350 for reference


From what I can determine from ADVICS (brand name) Original Equipment Lexus Front Brake Calipers - these two (Left & Right) caliper part numbers are for all 4GS RWD models:

ADVICS A5L079 Lexus 47750-22460 Front Axle Left Caliper for: LEXUS GS (2011-) _L1_ - 3.5 350 GRL10_, GWL10_ [01.2012 - present]

ADVICS A5R079 Lexus 47730-22460 Front Axle Right Caliper for: LEXUS GS (2011-) _L1_ - 3.5 350 GRL10_, GWL10_ [01.2012 - present]

Note also that the 4GS front calipers are 4-piston calipers, not 2-piston calipers that we have seen on official Lexus literature, including the Lexus website.

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The above front calipers are exactly the same for all RWD GS models. (Note: I believe the AWD models use a different front brake caliper that is required by the all-wheel drive system, but I am focusing more on the F-Sport RWD using 14 inch rotors versus the other RWD models using 13.1 inch rotors.)

The following five different GS models were used to obtain information about calipers for 4GS RWD models. (Note: VIN numbers are for salvaged vehicles or vehicles currently for sale):

VIN# JTHBE1BL9E5029285 - 2014 Lexus GS 350 F-Sport Pkg RWD

VIN# JTHCE1BL4E5021003 - 2014 Lexus GS 350 F-Sport Pkg AWD (I believe AWD models use a different front brake caliper that is required by the all-wheel drive system.)

VIN# JTHBE1BL0E5036318 - 2014 Lexus GS 350 Premium Pkg RWD

VIN# JTHCE1BL4E5020157 - 2014 Lexus GS 350 Premium Pkg AWD (I believe AWD models use a different front brake caliper that is required by the all-wheel drive system.)

VIN# JTHBS1BL8HA002129 - 2017 Lexus GS 450h F-Sport Pkg RWD
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While the 4-piston front brake calipers are the same for all 4GS models with RWD the F-Sport RWD model appears to use a different Toyota brand brake pad that has a slightly different dimension of the composition material to accommodate the 0.45" larger surface area of the 14 inch rotor as compared to the 13.1 inch rotor.

Note: When looking at the Akebono and EBC application recommendation both company's websites list the same brake pad for all 4GS RWD models with no distinction for the F-Sport RWD with the larger 14 inch rotor. It remains to be seen whether this is accurate, or not.

 

So... if the calipers are the same for GS350 F Sport and GS350 ‘standard’, then the only difference is the rotor and the caliper mounting bracket? Assuming this is true, one could ‘downgrade’ the brakes and utilize standard GS350 rotors by simply changing caliper mounting brackets? If the F Sport Brake Rotor is not truly advantageous without tracking the car, this seems a logical concept (assuming cost of caliper brackets is not outrageous).

thoughts??? Has anyone tried this? Seems to be reasonable.

 

Well, the Steering Spindle Knuckle (that the brake caliper mounts to) is the same for all GS RWD models. The AWD models take a different Steering Spindle Knuckle due to the front axle drive of the AWD models. So, even though the F-Sport RWD has larger front rotors the brake calipers and steering spindle knuckles are all the same. That means what you want to do ("simply changing caliper mounting brackets") cannot be done. (I originally presumed, like most people, that the brake calipers on the F-Sport was different to accommodate working with the larger brake rotor, but that is not the case. Then, after learning that the brake calipers are exactly the same for all GS RWD models, I thought maybe the F-Sport's steering spindle knuckle might be different, where the brake caliper is mounted at a slightly different angle to orient the brake pads on the larger rotor's surface so the pads cover a larger surface area, but that's not the case either. It appears that the brake pads for the larger 14 inch rotor have a slightly different composition material dimension, but use the same caliper...)

From what I can determine the only difference in the F-Sport's RWD brakes is the larger 14 inch front rotors (compared to 13.1 inch for all other models) that use a slightly different composition material size brake pad, and that the F-Sport RWD comes with 2-piece front rotors - some owners have elected to replace the 2-piece rotors under a TSB due to a clicking noise complaint with a one-piece 14 inch rotor... So, to answer your question about what is needed to replace the F-Sport RWD 14 inch brakes to the non-F-Sport 13.1 inch brakes - it would appear the change can be accomplished easily by just replacing the 14 inch rotors with 13.1 inch rotors and changing the brake pads to the non-F-Sport RWD pads ...and that's all that's needed! Note: Please let us know if anyone determines this is not correct...

► Toyota/Lexus #43201-30030 Right Side Steering Spindle Knuckle for RWD (that the brake caliper mounts to)
► Toyota/Lexus #43202-30040 Left Side Steering Spindle Knuckle for RWD (that the brake caliper mounts to)
► Toyota/Lexus #43201-30040 Right Side Steering Spindle Knuckle for AWD (that the brake caliper mounts to)
► Toyota/Lexus #43202-30050 Left Side Steering Spindle Knuckle for AWD (that the brake caliper mounts to)



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This is a used Toyota/Lexus #43202-30040 Left Side Steering Spindle Knuckle with Hub and Bearing, Shroud and ABS Sensor still attached for GS RWD models

 

So - if the ONLY difference in all braking components is the rotor size (13.1 v 14.0) and rotor composition (2 piece v 1 piece) it appears that all the issues with f sport brake squeaking is brought on by the rotor. Changing this component would appear to take you back to standard gs350 brakes from top to bottom.

someone needs to try this. It may be me as I’m nearing time for new pads and likely rotors on my 15 f sport!!!

 

That appears to be the case...change the rotors from 14 inch to the 13.1 inch, and change the brake pads to accommodate the 13.1 inch rotors and you've converted them.

What is amusing to me is the ruse that Lexus used when touting the brakes on the F-Sport model by using the 0.9 inch larger diameter rotor (less than ½" greater brake pad contact area), but using the exact same caliper as all the other GS models with RWD use and somehow they're able to have this setup accommodate two different diameter rotors. This can't possibly add any meaningful advantage over the non-F-Sport RWD brakes. The only real advantage of the F-Sport brakes in my view is the 2-piece rotor to reduce weight and keep heat away from the hub bearing during repeated braking in track use.

Maybe I'm missing something, but I don't see much to get excited about with the F-Sport RWD front brakes.

 

No interest in this subject?

No comments?

Lots of views, but no responses!

 

I'm interested and have been enjoying reading your thoughts! Keep 'em coming. I find all of it confusing too

 

I find this fascinating... And I have developed the infamous squeals.
The .9" increase in rotor diameter increases leverage over the smaller 13" rotor.
How much difference? I am not that well versed.
Does it make difference in real world driving? Maybe not; dunno.

But I do find this fascinating; thanks BC.
Gonna do the TSB "fix" soon...

 

Thanks! I'm learning about this topic as I try to research it...

What first stumped me was that all 4GS RWD models used the same front brake caliper - I thought the F-Sport RWD would have used a different caliper to accommodate larger brake pads for the larger 14 inch rotor. Nope! Then, I thought maybe the steering spindle knuckle might be different for the F-Sport RWD so the caliper could be mounted at a slightly different angle so the brake pads could cover the slightly larger surface area (0.45") of the 14 inch rotor. Nope! Then, I tried to find the exact dimensions for the brake pad's composition material to see if the same caliper could handle two slightly different size brake pads (a slightly larger pad for the F-Sport RWD and slightly smaller pad for all the other 4GS models), but I never could find definite information for both brake pads. I deduced that the one caliper for all 4GS models must be able to fit either size pad because that is the only way for the brake pad to cover the 0.45" larger brake pad surface area of the 14 inch rotor. I still would like to have confirmation that the F-Sport RWD pad's composition material is a slightly different dimension than the regular brake pad dimension.

(Note: I believe the AWD models use a different front brake caliper that is required by the all-wheel drive system, but I am focusing more on the F-Sport RWD using 14 inch rotors versus the other RWD models using 13.1 inch rotors.)

The bottom line is - I really don't see much to get excited about with the F-Sport RWD front brakes. If the TSB For Brake Squeal: L-SB-0001-20 'fix' from Lexus that kennyD has provided us doesn't take care of the constant brake squealing many most are dealing with on their F-Sport RWD I suspect some owners may just convert their fronts brakes to the non-F-Sport front brakes by changing the front rotors and the brake pads - two brake parts that are oftentimes replaced anyway on the F-Sport RWD when the front brakes need replacing.

 

Well, I'm having difficulty figuring out Akebono and EBC's application recommendations for the front brake pads for the 4GS and whether the F-Sport RWD model takes a different brake pad from all the other 4GS models. The official company websites list the same front brake pad for all 4GS models with no distinction for the F-Sport RWD. On the other hand, Toyota/Lexus recommends a different brake pad for the F-Sport RWD.

I'm confused again!

 

The real question is why did Lexus LIE in all it's past/current marketing material and website about the number of pistons on the non-f sport front calipers?

Makes you wonder what else are they lying about?

 

Now I’m curious, will the 2-piece rotor fit an AWD F-Sport?

 

You guys are getting deep, lol.

A little off topic, but if not for this forum, I'd have probably sold my last 3 Lexus' much earlier than I did. They're nice cars, but not perfect by any means. I've had various issues with each one of my Lexus that were not major, but annoying personally. With the info on this forum, I was able to "fix" most of them and live with it.

 

Did my own pads 2 summers ago and found 4 piston calipers on my AWD - won't complain that the marketing material told me they were supposed to be "2-piston".

 

I love this topic. I would like to get a hold of a castoff set of F-Sport rotors in good shape and see if they start squeaking or clicking in an otherwise known-good base model car. One would also have to get new F-Sport spec pads which aren't too expensive. I wonder if a dealership would let me go through the scrap bin and find some F-Sport rotors.

If anyone wants to do the TSB on a newer F-Sport and try to get the dealership to let them keep the old rotors, I'd be willing to buy them and install them on a base model, for science. We could see if they fit and then whether or not they squeal.