I recently had my front rotors and brake pads replaced from OEM to R1Concepts for my 2014 GS350 RWD F-Sport.

I am having this obnoxious loud noise which you can listen to
I have no idea what's causing the issue. It happens all the time, regardless of the weather or if the car has been sitting for a while. If I come to a sudden stop the noise isn't there as much, but if I am coming to a stop at a light or stop sign gradually, it is extremely loud to where it is heard by everyone around me and is somewhat embarrassing. The video I made was with my windows up, that gives you an idea of how it loud it would be if I had my windows down.

The set up I have currently are:

• silver eLINE Series Drilled and Slotted Rotor 2014 LEXUS GS350 Rear Wheel Drive F Sport Package; 1-Piece Full Cast Front Rotors
  • Brake Rotor SKU(S): 631-75035D,631-75034D
• R1concepts Brake Pads Optimum OEp 2014 LEXUS GS350 Rear Wheel Drive F Sport Package; 1-Piece Full Cast Front Rotors
  • Brake Pads SKU(S): 2551-1118-00
• R1concepts Hardware Kits Hardware Kits 2014 LEXUS GS350 Rear Wheel Drive F Sport Package; 1-Piece Full Cast Front Rotors
  • Brake Hardware SKU(S): 340-75006

Everything was installed professionally by a mechanic I've been going to for years. I haven't had the chance to take the car back to him, as I am not in the area currently and wont be for another month. I've put about maybe 500-600 miles since installation. I've also gone through the How to Break in New Brakes process. Although, this isn't my first set I've gone through on other vehicles. Never had this issue with OEM or EBC Brakes. This is my first time using R1Concepts.

Any guidance will help. Thank you!

 

Few years ago I installed an R1 set the pads sucked material was way too hard I chucked them after a few hundred miles and put in Akebono Pro-ACT. If that's not your problem then maybe needs grease between the pads and calipers (and shims if equipped). FYI many mechanics make the mistake of putting grease where the edge of the pads contact the hardware this is no good all it does is gunk up and cause problems.

I won't use any pad that needs a specific break in procedure.

 

There are 2 to 3 substantial threads on here regarding rotors, pads and brake noise. Lots of different solutions were attempted... some failed and some didn't. Do a search and be prepared for some heavy reading...!

 

The squealing noise you are having is a common problem with the front F-sport calipers. You will see when you search the threads. The noise is most likely from vibration between the caliper and brake pad shim. Try brake grease between the caliper piston and shim. If it doesn't work try using a rubberized shim. My Lexus OEM brake pads had 2 shims per pad. One silver stainless inside and a black rubber coated shim outside. They sandwiched together behind the pad. My Lexus pads had no noise but were grabbing and not smooth when slowly moving so I tried EBC green stuff pad and got loud brake squeal like you have (still had grabby brakes at low speed). Switched to Power Stop Evolution Z23 pads that come with rubberized shims. No noise and smooth braking so far after 2 months.

 

Perhaps you answered your own question. No brake squeal. Installed R1 brake components. Loud brake squeal.

As others have said, this is a well known, well documented F Sport issue.
I tried everything after having Textar pads and rotors installed. Textar makes the F Sport pads for Lexus.
The work was done by a local, excellent shop. I should have done the brake service myself, but I wanted to give them a little more work.
I highly suggested they use Lexus dealer parts, but they assured me they had done many of these cars.
Brakes were quiet for a month.
I installed new Lexus shims with proper brake component luberication; worked for 1 month.

I bought the TSB pads from Lexus and installed then a couple of months back with good results.
This was the third time I had the car apart.
They will squeal a little when cold.

The Textar pads had incredible bite, better than the TSB pads.
Good luck.

 

This is why I went OEM all round (brake pads, rotors, shims etc..) 3 weeks ago on my F-Sport based on all the feedback and input from this forum. Zero squeaks, zero issues, zero anything, just great braking and stop.

 

I got the TSB pads from Lexus of Stevens Creek in San Jose. About $100. Get new shims too.
Easy to install. I THINK your rotors will be OK.

Good luck.

 

Sorry to say, but oem rotors and shims are a must, while using akebono pads with zero noise.