Hi guys,

10,000km ago (5,000 of which are highway) I installed new front rotors and pads.

The braking was really rough and the wear on the rotors seemed off.
I took the brakes apart again and realized that the pins were dried/seized.
Once I cleaned and lubricated them the braking became much better and smoother however it is still rough.

The symptoms:
1. Totally smooth below about 45km/h
2. Smooth when applied very gently at all speeds
3. Somewhat rough between 110km/h to 70km/h when applied firmly
4. Really rough between 65-55km/h when applied firmly

The roughness is felt throughout the car, including pedal and steering wheel.
They do not really feel warped as the roughness is not a pulsating feeling, rather like a humming resonance through the car (similar to that of say an engine at high rpm).

The rotors are new RDA OEM replacement parts and pads are Ferodo ThermoQuiet.
I drive the car gently, and only ever applied brakes quite hard when they just were not getting smoother and the crosshatch pattern was on the rotors.

I have visually inspected them and everything looks fine, as has Pedders taken them apart and said everything is fine.

What should I check, and what could this be?

the series 2 were afflicted with uneven wear on the rotors, while they weren't warped they did need a skim to remove the high points, RDA and Ferodo are good brands but maybe they aren't playing nice? and getting the same results. You'd only know this if you get the rotors independently skimmed, I would not put any faith in Pedders they are an iconic brand that is focused on making money with the least customer service possible (yep twice burned zero return for me)

In my experience a warped disc is felt as a pulsating, not through the pedal so much as a pulsing change in the amount of braking force, more prominent at lower speeds. In your case it sounds more like a shudder, possibly you're missing the rubber-backed shims or they are worn out?

The shims on the back side of the pad?
The new pads did not come with these and hence none were installed.
The old pads did have them though.

Is there anywhere I can get a set from?

Some pads come with new shims, others don't. Price doesn't seem to come into it.

The shims are not a wear item and should be reused. Yet a lot of people just chuck them, I don't know why.
(actually, I do . . . )

You can always use the orange goop to stop pads from chattering.

Copper grease you mean Max?

I had the exact same symptoms you're describing, then had my rotors machined and it fixed the problem. Everything was fine during light/medium braking, but when braking hard I felt the noise/vibration. Kind of a grinding metallic noise.

Only thing is my rotors aren't brand new like yours. They've never been changed in the 4 years I've owned the car.

I feel it might be warped rotors. I bought a dial indicator to measure run-out so I'll know soon enough

Copper grease you mean Max?

No, it is more a silastic type stuff, basically it glues the pad to the piston. Stops pad chatter. Which is what those shims were for.

Personally, I hate anyone touching my brakes or the wheel nuts. My TL was fine, smooth brakes, no strange noises, etc.
Then my daughter got new tyres put on, first chance I got I backed off the wheel nuts and retorqued them they were all over the place. Too late, it now has wobbly brakes. Yep, it has new tyres, but it now needs a disc skim. Some people amongst the tyre fitting crowd are too thick for their own good.

Wheel nuts : Rattle gun bad, wheelbrace better, torque wrench best. ok?

Thanks Max,

What happened was I fitted the rotors and pads myself, however I did not grease the slide pin.
Anyway, the brakes were really rough and after some research I decided the first step would be to check the grease pin, which I found was essentially seized.
After cleaning/greasing it, the brakes became much smoother but still they are rough.

I am suspecting that possibly the rotors were warped from only one pad applying pressure and heating up the rotor unevenly etc, is this a common occurrence?

I don't know how common but it's exactly what warped my front passenger side rotor, so it's happened at least once before ;). In my case it was obvious the disc was warped when crawling (eg. in heavy traffic) and applying the brakes. The brake force would rhythmically increase and decrease with each revolution of the wheel. There was no pulsating feeling through the pedal and it was less apparent at higher speeds, though there was some moderate vibration that increased in intensity as the car slowed. This is quite different to what you describe in the first post, there was no noise associated with the problem. The 'humming resonance' sounds much more like pad chattering (missing shims or 'goop').

I feel an ever so faint pulsating at low speeds (say 30 and under).
The pad manual said not to use neither shims nor "goop". They are the Ferodo thermoquiet, and to be honest they truly are very very quiet and no dust.
eg, any other car I've driven, if you let it crawl a tiny bit at traffic lights the brakes always make noise, with these there is absolutely no noise.

Their feel is not great, but adequate for daily driving.
But yeah, this issue is getting annoying. I might have to swap rotors/pads again which will be annoying and such a waste of money

I feel an ever so faint pulsating at low speeds (say 30 and under).
The pad manual said not to use neither shims nor "goop".

Interesting! Did these pads have a thick gasket like material on the back of them? If so, that substitutes for shims or goop at the back of the pads.

Anyhow, you said you have a dial gauge - should be able to tell if the rotor is still unwarped.

While you are doing that, have a good look at the disc surface itself. You may detect shiny patches and dull/rough patches on the face, this comes from different grain sizes created by uneven cooling during metal casting, and can give you an uneven feeling at low speeds due to the different friction at those points.

Nothing you can do about that if that is the case, maybe photograph the differences and complain bitterly to the person who sold them to you. lol

Yup, once I get some spare time I'll check for run out.

The rotor surface looks even. It still has cross-hatch markings on it from when they were new and I've put 10,000+ km on them. The pads must be very easy on the rotor.

No gasket as such, this is how they looked (google image used):
https://e-a.d-cd.net/59d859cs-960.jpg

Simple matter of improper fitment, you must always clean and grease the pins with the proper grease

Machine the rotors as they are warped

Not sure what this series 2 thing is, certainly nothing I have ever heard of