Rear brake discs warped? 2017 Camry RZ

[Novicebutnice]

Hi,

I was wondering if anyone else has experienced this, where the rear brake discs are warped, but not the fronts.

I understand that on my car that the rear discs are solid and that the fronts are ventilated, but usually 80% of braking is done by the front brakes on most cars.

So if anything I would be expecting the fronts to become warped first (also based on my experience when I was a car mechanic).

The symptom is when braking at a higher speed, especially when going down a Hill like Mt Ousley I feel a very noticeable shudder being transmitted through the Pedal and I feel the rear of the car also shuddering very noticeably as well,

But the steering wheel has no vibration at all.

I have just shy of 40,000 km and I have owned it since new (I've had it about 2.5 years)

Thoughts?

Edited August 2, 2020 by Novicebutnice

[campbeam]

You may be interested to read these article about uneven brake rotor wear. 

https://www.mechanic.com.au/news/solved-the-mystery-of-warped-brake-rotors 

https://alconkits.com/support/brake-pad-info/110-the-real-truth-about-warped-brake-rotors

 

[Tony Prodigy]

I suspect the writer is getting a kick back from DBA don't you think ? 

Manufacturing can have a lot to do with it and I'm not sure how to gauge Toyota's quality control for their disc rotors. I have replaced my fronts not because of warpage but for being scored and didn't want to machine them. My rears are still original and are fine.

I think that over torquing wheels nuts can have a detrimental effect as is wetting the wheels when they're hot. You don't want to spray the hot disc with water. I would also say you probably had one or the other or a combination of both.

I never wash my car after it's been driven for this very reason. I'd allow it to cool down or just wait till the morning to do it.  

Disc rotors are pretty cheap so It may be a good time to just replace them and if you don't have a torque wrench, I'd get one. Don't let the tyre people rattle gun the wheels nuts to buggery either. One of my biggest bug bears. Have you ever tried to get a wheel nut loose after the Apes have had a go at it ? I nearly popped a vein in my head ! 

 

[Novicebutnice]

On 8/2/2020 at 5:39 PM, campbeam said:

You may be interested to read these article about uneven brake rotor wear. 

https://www.mechanic.com.au/news/solved-the-mystery-of-warped-brake-rotors 

https://alconkits.com/support/brake-pad-info/110-the-real-truth-about-warped-brake-rotors

 

I remember hearing that the hot pads keeping in static contact with the rotor once the vehicle comes to stop is one of the main causes,

I'm taking it in to Toyota on Friday for a supplementary oil change, and (because I'm a sucker) to update the SatNav maps (I figure I'l do it every couple of years)

I'll mention it and see what Toyota say 

Edited August 5, 2020 by Novicebutnice

[Novicebutnice]

13 hours ago, Tony Prodigy said:

I suspect the writer is getting a kick back from DBA don't you think ? 

Manufacturing can have a lot to do with it and I'm not sure how to gauge Toyota's quality control for their disc rotors. I have replaced my fronts not because of warpage but for being scored and didn't want to machine them. My rears are still original and are fine.

I think that over torquing wheels nuts can have a detrimental effect as is wetting the wheels when they're hot. You don't want to spray the hot disc with water. I would also say you probably had one or the other or a combination of both.

I never wash my car after it's been driven for this very reason. I'd allow it to cool down or just wait till the morning to do it.  

Disc rotors are pretty cheap so It may be a good time to just replace them and if you don't have a torque wrench, I'd get one. Don't let the tyre people rattle gun the wheels nuts to buggery either. One of my biggest bug bears. Have you ever tried to get a wheel nut loose after the Apes have had a go at it ? I nearly popped a vein in my head ! 

 

I don't have a torque wrench anymore, but I do have a breaker bar that is about half a meter long that I keep in the car.

I'm thinking about going to DBA rear rotors when it's time for new pads (depending what Toyota say when I take it in for a supplementary service)

What are your thoughts on RDA Rotors? 

[Tony Prodigy]

9 hours ago, Novicebutnice said:

What are your thoughts on RDA Rotors? 

I have no objection to RDA either. I don't remember why I chose DBA rotors for mine. On a price for price basis, they're much of a muchness.

RDA seem to have the same quality control as everybody else. If it's Australian made, that's good enough for me.

Forget Toyota, they're a rip off. Sorry Toyota, it is what it is.

I'd also invest in a torque wrench Stephen. They're pretty cheap these days and you don't need a fancy schmancy one either.

Trade Tools have great sales occasionally. You might want to keep an eye out for these

https://www.tradetools.com/

[Tony Prodigy]

10 hours ago, Novicebutnice said:

I remember hearing that the hot pads keeping in static contact with the rotor once the vehicle comes to stop is one of the main causes,

I'm not sure about that, but it's plausible although there would be some minute clearance between the disc and the pad, but if the sliders are getting sticky then the pad may not release correctly and remain in contact, somewhat, with the disc surface and create that hot spot.

I wonder though, if the pad can actually get hotter than the disc itself. I'm thinking not.

[campbeam]

On 8/2/2020 at 12:39 PM, Novicebutnice said:

The symptom is when braking at a higher speed, especially when going down a Hill like Mt Ousley I feel a very noticeable shudder being transmitted through the Pedal and I feel the rear of the car also shuddering very noticeably as well,

But the steering wheel has no vibration at all.

Last night when gently braking to a stop at the traffic lights, I noticed a bit of a pulse through the brake pedal which I am putting down to a high spot on the rotor. I recall that this pulse was a lot more noticeable a few years ago. After an interstate highway trip, braking was a lot smoother in that there was no noticeable pulse.

Looks like I am going on a highway trip next week so will be able to see whether there is any brake pulse difference when back home.

[ZZT86]

An experienced Toyota tech I know did say to me some months ago that Aurions do suffer from DTV or Disc Thickness Variation. After I get my tyres fitted, I'll remove the fronts discs to make sure the hub is squeaky clean & the disc mount surface is same before getting mine machined cos they're buggered. I'll change out the pads also if there's too much variation there. I can't say I've ever experienced a problem like this on all the Toyotas I've owned & driven over the years.

[Novicebutnice]

On 8/8/2020 at 12:14 AM, ZZT86 said:

An experienced Toyota tech I know did say to me some months ago that Aurions do suffer from DTV or Disc Thickness Variation. After I get my tyres fitted, I'll remove the fronts discs to make sure the hub is squeaky clean & the disc mount surface is same before getting mine machined cos they're buggered. I'll change out the pads also if there's too much variation there. I can't say I've ever experienced a problem like this on all the Toyotas I've owned & driven over the years.

I took my car in for a service back in December.

I mentioned the issue, as well as what it was that I was feeling.

And though the problem is now fixed I am still as confused as ever.

I'm a former car mechanic, I can feel what the car is doing etc.

I have felt vibrations caused by front rotor issues through the steering wheel etc.

With my car, as in my OP the vibration was coming through the pedal (little to nothing through the steering wheel), and as the temps increased (going down a long downhill, or even if braking at speed),

a noticeable and disturbing shudder from the rear.

Yet after the front rotors were machined the problem is now gone.

They removed all 4 rotors and checked for run out, and only the front had any run out.

The only other possibility is that the rear rotors were not seated properly, and when they removed and refitted, they re-seated flush to the hub.



Did you end up doing your brakes?

Edited February 8, 2021 by Novicebutnice

[ZZT86]

Sorry to all, I've been really lazy on the forums of late.

Yes I did get me tyres fitted & then got my mate mechanic machine the front discs using his on car gadget. It did the trick with no more issues & I'm hoping it stays that way. There was run out in the front discs as I suspected, I watched the machine grind it all out on both sides of the disc & front of the car.

We left the OEM pads on as they were like new.

Edited February 9, 2021 by ZZT86