gs350lex

I have a 2015 Lexus Gs350 F sport AWD Canadian vehicle. I bought this vehicle 1 year ago at 28,000kms had original brake pads and brake rotors on it which would cause the car to squeal/squeak and I would occasionally get a small pop sound upon braking. I decided to replace the brake pads at 38,000kms with Akebonos PROACT Ceramic Pads and the car stopped squealing but would continue to exhibit a pop and the pop was much louder and would sound like a loud slap/clack occasionally. At 40,000kms i took it to the lexus dealership telling my whole situation and they recommend that first I replace the rotors since they were on their way out so I did with the OEM rotors. I continued to drive and the pop was still evident so I brought the car back to the dealership at 41,000kms and after several inspections they told me a small pop is normal (as it used to occur with my oem pads anyways but it was much quieter) their explanation was that in these spring loaded brakes it is normal. However i told them the pop is more frequent and sounds like a clack/slap(like the pads are popping loudly into place sometimes and they responded that having these aftermarket pads was the culprit to a louder pop which i guess makes sense because they said it moves around a lot more. Many others on the lexus forum have replaced their pads with Akebonos without issues so im wondering why I am having issues. Upon doing further research someone said that the culprit may be the 2 piece rotors the lexus member said "There are actually quite a few posts on this topic here. There was a known issue with the two piece brake rotors that would create popping and clicking sounds from the brakes. New rotors seemed to solve the problem which tells me the rivets between the rotor carrier and rotor itself are susceptible to excess freeplay". I have looked into this but there doesn't seem to be anywhere to get good rotors especially since i live in Toronto (Canada) and second im not sure if replacing the rotors would solve the problem. Second i have read that there are fitting kits that sometimes solve this issue but upon asking a trusted mechanic friend of mine he said with these pads there are no fitting kits you could possible put on. I really don't want to go to oem pads since they are horrible for noise and many other GS members have replaced with Akebono pads and have extremely satisfied. I need help i want to know what is going on with my brakes. What is this loud pop/clack (sometimes sounding even like a metal clunk upon hitting the brakes)? Sometimes I'll hear it a lot in a day and sometimes I won't hear it for a while. Please help me out I bought this car to enjoy it and love it but having this pop/loud clunk makes me want to trade it in for a toyota prius (not even kidding......). The car currently has 44,000kms and I feel like i made a big mistake purchasing it. Please any and all help would be appreciated. Thank you Lexus Community.

SpicedRum

Scroll back through this forum on the 4th Gen GS page (where we are now) and read about this more. This is pretty much the only known issue with this car. The two piece rotors tend to pop a bit over time. Mine don't but it's still almost brand new and this seemed to be a problem with the earlier gen 4 models.

Have you swapped out the rotors with OEM yet? That seems to be the ticket to resolving the problem. Also there are aftermarket rotors available...again, scroll through and read the brake posts and you'll learn how to get this corrected once and for all.

My OEM pads are as quiet as a mouse. I wouldn't blame them for the noise--then again your 2015 may have different pads, or they are contaminated and creating a lot of noise.

gs350lex

Rotors are OEM and new (only have 2000kms on them) just the pads are aftermarket (Akebono)(pads have about 4000kms) thank you for your help will do appreciate your reply thats the only thing that bothers me about this car .

SpicedRum

OK--I didn't glean that the rotors were replaced. I admit it was hard to read everything in one paragraph (my eyes are getting old!) so probably just missed it. I see it now..sorry about the confusion.

Does the sound increase, decrease or stay the same when braking DURING a sharp turn? If it increases, I'm willing to bet the new rotors also exhibit the looseness issue between the rotor and it's carrier. Just because the rotor is new doesn't mean it also doesn't have the same problem as the original one did. It might also be some wear on the caliper brackets (haven't ready any complaints about that) or perhaps a component of the suspension is sticking. The pop sound may not be the rotors but the suspension. I doubt it though.

One of the recent (last 2 months) braking thread had a vendor that was offering solid rotors. I would look into that before anything else.

Don't do anything drastic with a prius purchase. This can be fixed! You'll hate the prius compared to the GS.

gs350lex

The sound stays the same when braking during a sharp turn. Ill give u an example I drove for about minutes to a nearby grocery store without a single pop. On the way home in my neighborhood (there are about 5 stop signs before i get to my house) it made a loud pop upon stopping at each one of those stop signs. Another instance would be yesterday I was driving in traffic (about 30minutes) and every other stop it would pop upon braking in a straight line at slow speeds/fast speeds. Sometimes it won't pop at all other times it will pop for more frequently. Sometimes the pop will be extremely loud sometimes it will be a quieter pop. Weirdest thing in the world and definitely the first time im experiencing something like this on any lexus / toyota vehicle.

I doubt its the suspension the car only has 44,000 kms (also had the suspension looked at several times thought this may be the issue as well but it wasn't) that would be extremely embarrassing for a Lexus. Got to a point i went to many other LEXUS dealerships to see if anyone had a clue one dealership told me to do the rotors and replace to oem pads (definitely not going to do that especially since the rotors are new and oem and pads are fairly new but aftermarket). I do agree with you on the " the new rotors also exhibit the looseness issue between the rotor and it's carrier" and i am hoping to God that this is the issue and can be fixed by replacing the rotor just really sucks that the rotor is brand new basically and will have to be replaced. Looking into putting on some EBC rotors. I definitely don't want a Prius but I also don't want a popping Lexus. My 12 year old Camry doesn't pop or make any noises this is killing me on a car that is twice the price and supposed to be much better. Rotor seems to be my only last solution. Also the pop seems to only come from the front driver side (well thats where it sounds like it's coming from) . Thought i had a seized caliper had lexus inspect that with no solution (all calipers seem nice according to Lexus (had 2 dealerships look at it)).



Thank you for your help I appreciate it more than you know. This pop is killing me and annoying me like mad. Lexus just tells me to live with it (trust me if they drove this car they wouldn't want to live with it)

er34

Good to see a fellow Canadian on the board. Mind telling me which dealerships you went to? Hopefully its not DVNL or RH.

I have the AWD with Akebono as well and I have no issues whatsoever. Usually clunks come from suspension components but if you insist its the brakes, I would check the brake pad retention pins on the front calipers since that is the only part that seems unchanged. Also make sure the edges and back of the pad are lubed up real well. The Akebonos come with a small packet of molydenum lube which is really good stuff.

er34

OP has AWD model. It doesn't come with 2 piece rotors in any case.

gs350lex

Hi the dealership i have gone to are Lexus of Oakville (where i originally bought this car) & Lexus of downtown(this dealership tried to make me to do another rotor job and tried to make me switch back to oem pads). I insist that it is the brakes because this loud pop only got worse when i changed from the OEM pads to the Akebono pads. When i purchased the akebono pads i had an independent mechanic install them but I've never had any issues with him and he always done a good on my other cars. He lubed up the pads and everything seemed fine but than over time i had these loud pops upon braking. The pops were evident before with oem pads (but the oem pads squeaked too so i had to change them). The pops are much louder now and they occasionally make a loud pop almost sounding like a slap/clack. The only thing i can attribute this to is the brakes because it seems as if these pads are moving around a lot which seems to be causing my problem.

These are the pads i bought from tire rack : (Akebono Proact)

https://www.tirerack.com/brakes/brakes.jsp?make=Akebono&model=ProACT+Ceramic+Pads&group=ProACT+Ceramic+Pads&partNum=ACT1118&autoMake=Lexus&autoModel=GS+350+F+Sport&autoYear=2015&autoModClar=AWD


I've complained to lexus so many times to check out the suspension/calipers/brakes and whatever else they just tell me nothing is wrong. I don't know what else to do

Also i was under the impression that we had the 2 piece rotors as well ? Thanks again must've been misinformed

Thank you both for responding !

er34

As I wrote, I suggest checking the pad retention pins on your front calipers, and possibly replacing them - should not be too expensive. These could be bent during install or rust over time in our winters, that may cause prevent the pad from retracting smoothly causing the pop.

Pads and rotors shouldn't cause pops or clunks.

gs350lex

Ok i will give it a shot (and sorry for mentioning clunk it is more like slap/clack noise rather than clunking its just really annoying) . Have you heard of anyone else experiencing similar symptoms ?

Thanks again fellow Canadian

er34

Not for the GS, but for this type of caliper, I've seen this happen. Here is one example:
https://www.scoobynet.com/suspension...g-forward.html

Also, check all the caliper bolts are tightened properly(though I assume the dealer already checked this.)

SpicedRum

OP==I apologize, I honestly did not realize our AWD models do not have the 2 piece rotors. Guess I better stop opening my trap before knowing all the facts. Sorry about that.

The pin or perhaps oversized or elongated holes on the pads and brake carrier tightness would be worth a look. I have to believe the stealerships checked but I"m thinking trust and verify here.

Another totally off the wall idea is anything related to the brake pedal assembly or the brake line retainers. Any obstructions, loose joints, etc. Hope you can get this sorted out.

Sybaritic

Hey fellow Torontonian, this pop sound, does it also happen when you release the brakes and accelerate? I sometimes get a sound sort of like two billiard ***** hitting each other. The service manager at Lexus of Oakville (where I go to as well; love the front staff, not the warranty guy who wouldn't warranty my Nav screen when it keeps resetting, so I won't ever spend any more service dollars there) told me it's the brake pads springing back when the brakes are released and the rotors turn with the wheels upon acceleration.

I say try two things: Make sure you have brake pad shims. The OEM set up I recall has 3 shims per side. If you don't have any shims, or they're aftermarket shims, try taking out the pads, put a thin layer of silicone on the backing of the pads, and see if that helps. The silicone will create a cushioning effect that might eliminate noises. I used to do this on my other cars when I used aftermarket pads that didn't come with brake pad shims. (I always prefer OEM pads and shims for the nice, solid fit personally). Our brakes are pretty easy to do. I did my front pads and rotors on my own after Lexus of Oakville quoted me like $700 (LoL).

Sybaritic

Is this the white 2015 F-Sport you bought from that dealer a year ago? If so, I test drove it.

er34

Wow we should do a Toronto 4GS meet. I definitely don't see many 4GS around(I'm in Mississauga). I only recently started seeing a 2015 Nebula Grey driving around in my neighborhood. I always keep an eye on AutoTrader for nice GS samples too, there's never that many of them listed.

My recommended dealership in the GTA is Ken Shaw, their sales and service department are both top notch in my experience. The absolute worst are DVNL and RH. Erin Park is pretty shady too. Never dealt with Oakville. It's too bad there are so many poor Lexus dealerships but at least there's many to choose from within 100km.