My newer brakes suck!
 

Ok guys about a year ago a replaced all my rotors with slotted and drilled and ceramic brakes all around since original were worn and had shake upon hard braking. Now from very replacement it did not brake great I was hoping it would get better but I think it's progressively getting worse. lately I've been noticing more and more wheel shake as I brake hard this shouldn't happen with newer rotors and brakes ,what's going on here any ideas? Bad pads or rotor quality? I bled the entire system after brake replacement. Only put on maybe 8000 miles
rotors are R1 concept , I had them for many years on rear of my e55 and no issues

Low quality rotors.
They are warped.
Some places will still turn them for you.
Or put stock back on, they are good.

This is typical with many rotors, the quality can vary by a large amount.
I was going through the same thing with rotors on my truck from Advance auto, after 3 pairs I ditched them and went with O'reileys and never had a problem.

Could also have glazed spots on the rotors from holding brakes on at stop.....highly heated discs. Ceramics are tend to exchange braking performance for lower dust which may increase heat.

Alex

Why not name and shame the brand you fitted so that others can avoid?

Notice you drag yours, do you think that has compounded the issue?

No probs with my wortec rotors and ebc red combo, but then am a pretty sedate driver :)

Cheap rotors. Start by replacing the fronts w/ good ones. If the car still shakes then replace the rears. Do keep keep the pads. Ceramics are probably not the problem, It's the rotors.

How are you driving it after new brakes?

"r1 concept" is the brand but I never had issues with them for years running on rear of e55 AMG but then again this is on the rear weher load is less. don't think drag racing has much of an effect since I don't brake torque much if at all when I drag race

I would pull the wheel and put a dial indicator on it to see what the run out is. Check to see if there is any material deposits on the rotors. Go from there.

I've commented on R1 in the past, only because I followed them from their first bogus 'V slot' design, and their claims of superiority. (Their R&D department was their buddy running his car in local motorsport events.)
The fact was that they knew nothing about metals or metallurgy, but they did know that no one else knew about it as well.......so they bought a CnC machine, polished up a set of cheap rotors, slammed them through their drill presses and put pretty pictures up on FleaBay for the ricer kiddies to buy.

Sadly, it worked, as pretty pictures and cheap prices kept those unwilling to research rotors, and believe they were getting the performance bargain of a lifetime.

R1 has grown from its questionable beginnings, and maybe they actually bought all the correct equipment to make something reasonable these days. I do recall they now offer known and trusted brands, if for no other reason but to pacify those that actually know something about rotors.

I finally gave up trying to explain to people how I felt about a company with such shady beginnings, because in the end.... regardless of the knowledge that they made an inferior product, the 'pretty pictures and cheap prices' seem to dominate todays buying decisions.

As I said.... Maybe they are different today. Maybe they have learned a bit more over time.... But I personally wont touch them with a ten foot pole.

The standard discs are from ATE and they are of very good quality even if they might look ordinary.

During the life of a set of discs (or should I say rotors here) they are usually subjected to aggressive environments, from heat to corrosion. The faces eventually don't have an even layer of pad material on them, making for uneven braking. Corrosion can lead to hard spots (cementite) that don't want to wear down resulting in high spots, reducing how well the pads contact the disc and create more localized heat which promotes more cementite. Cementite is very hard and has low frictional characteristics. If the disc is looking more uneven, dirty grey rather than shiny silver, and they seem to be less grippy than expected, they are probably past their best and low quality discs seem to "go off" sooner than good ones.

If you have the 5.0 XKR, finding a better road pad than OE (Jurid) is not at all easy. All other OE pads seem to be from ATE (or Galfer, the OE pad wing of Continental) and are also good.

As mentioned above, most ceramic pads are a low-dust trade-off and you have to accept lower performance than the very best normal pads.

My local Jaguar indy shop says to only use Jaguar parts for reasons like this...

Same here. I was discussing this with the indy that I use for service and light maintenance and he was adamant that I used Jag brakes and rotors when I need them. He's not the type of guy to up sell for profit either. He's got 30 years on Jags and he said they were the best, albeit dusty! It's ok with me as I use OEM whenever possible anyway.
YMMV

Thanks for that!!
Very good to know in general that the aftermarket auto accessories industry has these schemes.
It makes sense, if nowadays we have the ability to fake something as big as news, the rest is child's play.

In my industry which also supplies car manufacturers.
The acceptable rejection rate (out of spec) is like 1 in 10,000 or more, in some cases its 1 in 100,000
The same part outside of supplying OEM, tolerance is like 1 in 50

If the manufacturing process naturally produces 10% defects.
For OEM It has to be filtered to get it down to .0001%
This 'eats the lunch'- and OEM manufacture is a zero sum game.
You make it up in the aftermarket.

It sounds like Jaguar has also insisted on very stringent R&D on the rotors.
To end up with rotors that on the whole outperform even performance names.
I assume they outsourced that R&D to the manufacturer of the rotor itself?

This is a safe, and certainly the best avenue for those that don't want to study or understand metallurgy. However, there are many reputable retailers out there that have high quality specifications for rotor manufacturing (most all are made in China now, but reputable names demand certain compounds and QC before carrying their logo).

Having spoken with former staff from Power Slot (prior to being bought by Centric/StopTech), the metallurgy was controlled in-house, as the was heat treatment process. Power Slot also owned the cryo facilities for normalizing a casting, which Centrics/StopTech inherited in the buy out.

Point being, there are companies out there that take their business seriously, and, offer products far superior to Jaguars OEM.
You just need to understand the importance of metallurgy to make the best choice for you.

I strongly agree that OEM is a safe bet, and I highly recommend them. But there most certainly are better choices than what Jaguar has on their shelves if you are truly interested and willing to do some studying beyond fluffy pictures.

Vince

Continental is one of the biggest component suppliers in Europe, so you would hope they have the know-how to produce a good product. It appears that, in general, brakes are sized to suit the weight and performance of the car and a system is put together from available components, where possible, and, I expect, the ABS tuned to suit the actual car. Looking at the pads for the 5.0 S/C cars, that size/fit was also used on many of the more powerful/heavier BMW 5, 6, and 7 Series cars of the same era, also some Rolls Royces. The front calipers also look very, very similar!

I would only buy brake parts from suppliers who supply car manufacturers as an OEM. At least they have good technical knowledge and the size to make a product of the quality they want. One just has to hope that that they haven't set the bar too low for the aftermarket supplies.

There are aftermarket companies that exceed oem standards and are better . On my E55 AMG I went with Disk Italia rotors slotted and drilled for the front ( $500 for the pair) and R1 concept for the rear slotted and drilled, Akebono ceramic brake pads all around. I can tell you guys the car is the best braking car with the setup that I ever had with any cars I owned. 7 years later there is zero wheel shake, they bite hard at any speeds and there is minimal wear on rotors and pads plus on top of this there is very little dust.
I wanted to go with the same pads but could not find them for the XKR. Maybe it's the cheaper pads that are the problem and over time ruined the rotors?

Here are the suppliers to the 2007 Jaguar XK. Brake pads were manufactured by Honeywell. Download the .PDF file and enlarge it to see the details.

http://edit.autonews.com/article/200...2007-jaguar-xk

Honeywell has since sold its automotive braking business to Federal-Mogul who now have the Jurid brand from Honeywell to add to their own Ferodo brand. These were probably the "Honeywell" pads fitted to the early XKs. Some (all?) Jaguar-boxed ones still have Jurid stamped on the, so it looks like Jaguar still buy the same pads.

Here is a great video that shows you what R1 is not....................

Vince