The cause of wobble?! Brakes doomed...

[Rem Zuk]

Good morning/afternoon!

 

I've got GS450h, 2008. Bought it from a dealer half a year ago. All was fine, just noticed at some point brakes started squeaking when backing up... Then the disk most likely overheated and started wobbling while breaking.

End of July I went to my homecountry (yes, Eastern Europe...), and gave my car to a mechanic from local Lexus/Toyota dealership. He's been looking after my family cars for years now, including my mom's RX400h and two PRIUS'es prior that, so kind of trust that guy...

Long story short, about 2000 miles down the road and back Home (here, London. Trip done non- stop pretty much, so enough time to over heat), my breaks are same, if not worse!!! Obviously, gave a call to mechanic, as my first idea was seized break caliper piston. He claimed they checked both sides and calipers were moving freely, so shouldn't be the cause. 

Could someone please advise what could possibly be the problem? I was told it could be the hub that is bent a bit that is causing that (pre-history of the car has nothing, but it clearly has had some accidents, as both rear and front bumpers are resprayed, and quite poorly, I must add...).

 

Any advise is very helpful!!!!

[Ben01]

First question, one wheel? all of them? rear? front?

Second, if your guy has checked cold callipers, maybe it was fine, but hot calliper could seize piston or pins or even pads only. I have seen this before. Maybe it is worth to check hot brakes for seized parts, before other (and expensive) moves.

[Rem Zuk]

Sorry, forgot some details...

One wheel (same as before), front right (driver's side)

Hmm, never actually thought of that...  Thank you, Ben01! Got a longer trip planned for Saturday to Boston, so will try and see weather it get's worse when I get there!

Fingers crossed it would be that, otherwise it will be a very hard month on a wallet...

[Ben01]

If one front wheel it is probable seized anything (piston, pin(s), pads itself even), hot only, or cold and hot, very common problems on elder toyota/lexus. I struggle with same in both previous (but elder and worn) GSes.

If it will be two or four wheels, you could be really sorry for your wallet funeral, as this marks up the brake valve unit/pump, etc. and that is I call expensive break down.

[Rem Zuk]

5 minutes ago, Ben01 said:

If one front wheel it is probable seized anything (piston, pin(s), pads itself even), hot only, or cold and hot, very common problems on elder toyota/lexus. I struggle with same in both previous (but elder and worn) GSes.

If it will be two or four wheels, you could be really sorry for your wallet funeral, as this marks up the brake valve unit/pump, etc. and that is I call expensive break down.

Yeah, sounds like I got myself in a bit of a trouble then... Well, on Tuesday will try and see a mechanic and will have it checked there... Thanks, Ben! Great GS-history of yours, by the way!!!

[C.B]

Is it not just the discs warped? I had this recently on my wifes honda, very noticeable when braking from speed on the motorway initially but eventually could sense it most of the time.

Got the discs checked and they were only ever so slightly warped (and 6 months old) but combined with the heat of a long drive was driving me nuts.

New discs..problem solved.

[Rem Zuk]

3 minutes ago, C.B said:

Is it not just the discs warped? I had this recently on my wifes honda, very noticeable when braking from speed on the motorway initially but eventually could sense it most of the time.

Got the discs checked and they were only ever so slightly warped (and 6 months old) but combined with the heat of a long drive was driving me nuts.

New discs..problem solved.

Morning, C.B.! 

Well, you're right about the first part- I am 99% sure it is a warped disc! The issue is, the disc got warped, I got both of them (including pads) changed, and after mere 2000 miles the new one is warped again! Changing it is solving the consequence in my case, but not the cause...  

[C.B]

I had a similar fear, sourced the first discs myself and got fitted by a friend. In the end I have had zero come back the supplier will not accept the discs back.

New set fitted by national where the manager assured me if they warp that quickly they will replace them FOC and send them back to the supplier. Return power of one consumer versus a major purchaser. Lesson learnt since I have had to but them twice in 2k miles 😞

[Rem Zuk]

3 hours ago, C.B said:

I had a similar fear, sourced the first discs myself and got fitted by a friend. In the end I have had zero come back the supplier will not accept the discs back.

New set fitted by national where the manager assured me if they warp that quickly they will replace them FOC and send them back to the supplier. Return power of one consumer versus a major purchaser. Lesson learnt since I have had to but them twice in 2k miles 😞

Yeah... Cheap person always pays twice... Same mistake as mine, by the looks of it! Well, I am hoping soon it will be just a bad memory and once again I will be able to enjoy the ride!

All troubles aside (not that I had a lot, they are just quite expensive...), love the GS to the bits!

[Rem Zuk]

Right, so not to leave the topic open, wanted to share the outcome...

So, decided to try one last thing before going to proper dealer (yes, I know... Had this lesson loads of times- you cannot be cheap for these cars...). As it was getting worse and worse, I got it to a mechanic to be checked out (he said all was ok). He forwarded me to another garage that does skimming. After all was done, the owner told me something that bugged me for a long time- he was overlooking the process, and it did not look like they were warped... But as I left the garage, the car was braking beautifuly! Till my next few longer trips... And then it started coming back again! Imagine my dissapointment...

As it was getting worse yet again, I started thinking of causes- and already made up my mind to get it all done in the expensive way. Was about to, but managed to get myself into a motorcycle accident (amazing black cab drivers think that side mirrors are just for image purposes...). Either way, had other expenses, so had to put vibrations lower on priority list. Till one day read somehwere here on a forum possible cause!

I noticed, that jugle would become a bit stronger after every longer trip on motorway. Apparently, when I would brake after long trip (a bit warmed disc and pad), the would be dust residue that would get stuck on a disc and would cause all the issue above! Few hard brake checks (not coming to a full stop though) from about 40mph have reduced the problem by a good 95%! Might change my pads to a better quality ones (not sure what is it there now...), but that seems to be the end for this issue!!!