Hi - I've posted on here many times recommending R1 Concepts drilled and slotted rotors which I have on my 2010 Jaguar XF 5.0 supercharged. However I'm having some serious issues and looking for guidance

I first put them on about 3 years ago - part of a kit with the R1 Concepts rotors and centric semi-metallic pads. After about 18 months (5000 miles) I got very bad pulsation in the brake pedal when braking.

So I bought replacement R1 Concepts Eline drilled slotted for the front and EBC redstuff pads and carefully installed myself, cleaning the hubs etc. Still pulsation so replaced the rears too and all was perfect

However 10 months on I suddenly have pulsation back again when braking. I had the whole braking system checked carefully by my jag dealer and they told me all was working fine. And that there were 'hot spots' on the rotors that were causing uneven wear and vibration. But they couldn't explain why that would happen in normal driving (no track racing etc).

R1 to their credit sent me replacement rotors free under warranty no questions asked. So I fitted them today. But how can I be sure this won't happen again? Wondering if I should go back to stock rotors...

Attached some photos. Fronts looked worse. Eg front left rotor in photos below you can see a black mottled patch on the outer face of the rotor, and a strip around nearly half the rear face where it looks like it wasn't making full contact. I also noticed when I jacked it up and span the front wheel that it span freely around about half a rotation then rubbed the brake pad for about 1/4 of the rotation with a grinding noise. Same on both front wheels. So presumably that patch is rubbing every rotation of the wheel and must be getting very hot...

Anyway - guidance and input welcome. Is it warped? Uneven wear? Pad deposit? And most importantly why - and does it point to a poor rotor or a brake system issue?

 

I fitted a set of slotted and drilled rotors to my old XFR about four years ago, not R1 Concepts but they look absolutely identical to those in your pics and I would bet they are in fact identical. I also got them as part of a package deal with new pads that were falsely advertised as ceramic when they were in fact Centric PosiQuiet semi-metallic.
Never had a single problem with them over two years and around 16,000 km other than annoying amounts of brake dust and still some graunch just as you come to a stop. About half as bad as the stock pads.
When I sold the XFR I took those rotors off and put the stockers back on, and I swapped the front rotors over to the F-Type. I couldn't swap the rears straight away as my F-Type came with the puny 326 mm rear brakes instead of the much better 376 mm ones. But about 15 months ago I upgraded the rear brakes to the 376 mm ones and then put the rear slotted and drilled rotors on. At the same time I also swapped out all the brake pads for Porterfield "carbon/kevlar" R4S.
Not a single problem with either the rotors or the pads all this time, in fact the rotors are wearing amazingly well and evenly, with only the faintest hint of any lips after some 36,000 km across both the XFR and F-Type, I am very happy with the quality of those rotors.
Moral of the story - before you chuck the rotors get them skimmed/machined, get some Porterfield R4S pads, then bed the rotors and pads in properly.
What has always worked for me with bedding in new rotors and/or pads is eight or ten hard brake applications one after the other, from around 60 mph down to around 10 mph (don't stop!) until you can smell the pads getting nice and hot. Then, without stopping, cruise on home doing a "cool down lap". Never failed me yet and I have never had a problem with brake pad deposition, imprinting, hot spots etc across several sets of rotors.
Only two downsides to this - finding a reasonably long and quiet piece of road with no popo around, and at least for an old fart like me it makes me quite nauseous!

 

Thanks Oz. Yes - I remember I bought that same pack as you initially with the centric semi Metallics

It's good to hear that you've had more luck than me with these. I did do the full bedding in and for a while they worked very well. Not sure if I should re bed every 6 months or so. But the car is used almost daily with regular fast highway runs and braking so I'd have thought they should be 'cleaned' regularly
I wondered if they weren't quite mounted square so I very thoroughly cleaned the hubs, took off all corrosion etc. interestingly the front left rotor was pretty welded to the hub and had to use a mallet and quite some bashing to get it off. Others were ok. That rotor was the one that seemed most damaged so perhaps an issue on that wheel. But I relubed the caliper pins and checked the calipers which seem to move fine, so I don't see anything wrong. And dealer thoroughly checked the brakes too and thought they were working fine

Any other ideas welcome. Else I'll be testing and seeing what happens

Any chance the vibration from a bent wheel can cause it within a few weeks

 

Ok - I've replaced all four rotors with the new ones R1 sent me and the pulsation is gone. But the braking is still not very smooth. I had noticed with the old rotors that when I free spun the front wheels while jacked up, there was a grinding noise for about 1/3 of the wheel once per revolution. I assumed that was due to the old rotors but wanted to test.

So I just jacked up the front left of the car and spun the front left wheel by hand (it's a rear wheel drive so I would expect it to spin very freely). No foot on the brake pedal, parking brake wasn't engaged etc. it makes a grinding noise for about a third of each revolution and only spins once or maybe twice before it stops. And there is resistance to turning during that area

Did the front right and the same issue - for over half the wheel and significantly more resistance. Of course can't do rear due to transmission

So - what's going on? Surely if it rubs the same spot every revolution the disc will get roasting hot there, unevenly deposit pad or warp. Given I've lost 2x sets of rotors in a row is that my problem?

I thought of carpet sticking but wouldn't that rub all the way around? I thoroughly cleaned the surface of the hub to remove any rust and debris before mounting so am pretty sure they are mounted square. Could my hub be off center? The caliper bracket bent or misaligned??

Am going to try to attach a video to next post if that's possible.

 

Here is video of the front left wheel when jacked up. Notice grinding noise between the red tape markers

 

And here is the front right

 

Definitely something wrong there but I don't know what it is as I have never had that issue.
But it doesn't sound at all like the rotor rubbing on the brake pad to me, it sounds much more like metal on metal.
It could be the rotor scraping on the rotor splash guard but then again I can't remember what those splash guards look like on the XF, but I suspect they are like those on my F-Type (identical front brakes) - tiny little things covering a couple of inches at the bottoms of the rotors. The rear splash guards are much more substantial and go pretty much all the way around. Best to have a close look at those front splash guards, one or both may be bent outwards a little. Also I have read of little bits of gravel getting stuck between the splash guard and the rotor.
You can test the rears as well, they will rotate.
You need to start the car and put it in N, then turn it off.
It will then stay in N for 10 minutes before it automatically goes back into P.
Obviously do not apply the parking brake!
To give you enough time best to get the rear end up off the ground first on axle stands before you start the car and put it in N, but it only needs to be a cm or so off the ground.

 

Just a thought but could wheel bearings be the culprit?

 

Definitely sounds like brake rubbing, especially on the right hand side, rather than the wheel bearing that's actually making the noise, although I guess the wheel bearing could be responsible for the brake rubbing. Have you tried giving the wheels a good shake while off the ground to check for any untoward (esp. lateral) movement or noises? I have to say though, I think if the wheel bearing had enough play to make the brake disk scrape it would surely be noticeable as a hum while driving.

It does sound like something to do with the brakes. I don't think caliper alignment could cause an intermittent noise like this, it sounds like either the disks are warped or it's not mounted flat, but you said you've cleaned any rust etc.

If you've checked for excessive wheel movement, as well as taken the wheel off and made sure all caliper, brake brake disk, and wheel bolts are tightened correctly, then really the only option as far as I can tell is to run a on it to check for straightness. Not sure how well the works with slotted disks but you could probably get a good idea.

EDIT: Another thought - take the wheel off and see if it still makes a noise or if the brake disk rubs on pads etc - you should be able to rotate the disk by hand, but you won't have the weight of the wheel pulling on the bearing.

 

Assuming the rotors are true straight, the grinding could mean they are not seating flat against the hub? Or the wheel nuts are not getting torqued down evenly causing the rotor to tilt. At this point it maybe time to try going back to stock just to have proper working brakes.

 

Thanks everyone for the helpful responses and ideas. The hub is a good thought - I did have the dealer check during annual service last month given the vibration when driving and they said all was fine but that noise was around then and they didn't comment...

Will take off caliper and spin to see if it's hub or brakes. If brakes I'll do some more detection to see what is actually rubbing

It's hard to believe it's 4x bad rotors twice in a row a year apart so not sure replacing with stock will help. But let me work out if it's hub or brakes first

Will post back!

 

+1, that's the splash guard rubbing the rotor on both issues. They are very easily bent during wheel removal, just bent them back. As far as R1, used thier products many times over the years and NEVER an issue, but I will say one reason I stopped doing slotted is because I could always feel the slots as feedback (Vibration) in the brake pedal.

 

Hi BritCars,

I followed you from my X351 thread. I would highly recommend getting ChassisEars (~$100 on amazon). It made my hub issue really obvious. I just got the regular wired kind.

If you want to PM me I'll ship you my set to borrow; just mail them back to me when you are done.

Best of luck,

Nick

 

 

Thanks everyone for all the replies and Nedoeer for the kind offer

So I took it back to the dealer today and they thoroughly checked the brakes. Spun the front wheels and said it all checked out perfectly. I was skeptical as I jacked up front left to check last night and still got the grinding noise. So they took me into the shop and showed me with the car on the lift. They let me spin the wheels and all seemed perfect - they freewheel spin a half dozen times with no sound and gradually stop.

So - not quite sure what to make of it. The best I can think is that jacking up one corner is twisting the car in some way causing the rubbing?. Whereas level on the lift was ok. But I can't picture geometrically how that would happen.

Anyway I'll keep a close eye on it and will check again in a few weeks. And fingers crossed that all is great!

 

https://ebcbrakes.com/articles/pro-cut-lathe/


May help. Good luck.

 

Sorry to revive an old thread, but was there ever any resolution on this? I'm also dealing with bad vibration when braking with my R1 slotted rotors and EBC Red pads. When I installed them, I was meticulous about everything, so was extremely surprised. I took it to multiple places to shave the rotors, high-speed balance, etc. and they never really found anything causing it. I suspect it could be the control arm bushings (which are definitely bad), or, as others have mentioned, possibly the hubs (which I haven't diagnosed as bad, but could be, I guess). Anyway, I just wanted to check up on this in case I need to get some new rotors while I'm at it.

 

Very timely Reaxions - sadly not resolved. The replacement set that I put on in 2019 is now pulsating on braking just like the others. We've not done a lot of miles on that car due to covid and remote working, so it prob only has 7000 miles. And there is heavy pulsation when braking from highway speeds

I bought a runoff gauge a couple of wks ago and when I get a chance will check all four rotors to see which (or all?) are uneven. And will also test the hub faces too. But overall very frustrating

There is no play in the wheel when car is raised. Suspension and all joints and linkages look fine. Dealer checked it all out and no issues. So I don't understand what's causing it. Maybe I go back to oem rotors and pads (dealers advice) but I like the drilled slotted and the ceramics for low dust.

I'm guessing it must be a hub but dealer felt all four were fine. Car is at ~70k miles so not high mileage. Or something bent somewhere?

Feels like guesswork at this point...

 

I assume you've already had the rotors turned?

 

I have not had them turned. This is the third set that are pulsating so it's clearly not the rotors themselves. There must be an underlying issue causing it which I'd like to track down