A little background info:

1. When I bought the car CPO, front brakes were squeaking so dealership replaced front discs and pads. Rear discs/pads have about 30k on them.
2. I have a V6S and I mostly drive it like a manual.
3. I've had it since last fall, and my first 'spirited' drive this spring resulted in brake vibrations.

I think my driving style plus the drastic "on/off" nature of the brakes led to this issue. Since I am often engine braking, I tend to apply light brake pressure. I also really like braking SMOOTHLY, so I'm rarely very stabby on the pedal. I think braking this way on the highway from speed repeatedly led to some glazing, and now I have 'warped' discs, or at least discs with high/low spots due to pad transfer. At one point I could see the shape of the brake pad on the disc, imprinted, probably from coming to a full stop on overheated brakes.

Anyway, the brakes still operate well, and while the vibrations come and go, they don't go away for good, and they make the car unstable.

I'm a bit cash strapped at the moment so want to start small. Based on research I think my options are:I'm looking for experience, opinions, or other options. I am thinking of starting at the top of the list and working my way down. But, I also don't want a repeat of the problem, so am considering starting at step B, and am considering Porterfield RS pads.

Thoughts? As always, I appreciate the help.

 

I'm not sure your driving style = glazing = your symptoms. But, as you noted, the car has prior history, so lots can be left to the imagination.
Personally, I'd suggest getting having the disc's inspected for warping/wear and hope their OK for now. At 30k, they "should" be good through another set of pads.
If so, go with the Porterfield R4-S pads. From what you've written, I think you'll like their feel. They're a little less "grabby" than the OEM's and, the brake dust is much better. In all likelihood, your JLR dealer won't be interested in doing this repair (non-OEM pads and no discs), so you'll need to use an independent.

 

This thread made me remember I have a similar issue, so I thought I'd hop on (hope you don't mind OP):

My rears have been squeaky lately, my local independent jag shop figures it's from the new rear pads that the dealer installed a while back (I guess they weren't bedded in).

He mentioned a "procedure" that he often uses in such cases:

- put in in reverse
- give it some gas
- hit the brakes while continuing to apply throttle
- brakes will chatter and re-bed (I guess?)

This was relayed to me over the phone so I might be forgetting/missing something. Could anyone elaborate or clarify this procedure?

 

Might check this out:

https://centricparts.com/getmedia/bd...c-8-2018_1.pdf

 

I have read the same in other areas of the web, but this is a very nice description of what I've learned. This is why I tend to think I should be able to get away with turning the discs and replacing the pads, especially since the front discs only have a few thousand miles on them.

That said, now I'm considering just getting new discs to be done with it and avoid any future issues.

 

You can try to do some hard stops to get the brakes really hot, like a bed in procedure. This might help to even out the deposits and create a more uniform layer of deposits on the disc surface. One thing to avoid when the brakes get really hot is the use of the parking brake. You don't want to use that if you've been doing spirited braking since it will leave a melted layer of pad on the disc. A disc with a high friction surface to clean the discs (like EBC Yellow Stuff) could help, or just having yours turned as you suggest.

New high-quality Brembo discs aren't too expensive. I just ordered a new set of 4 for $327 incl. tax and shipping.

 

I'm interested in this, can you share the part numbers and retailer? I only see the rear rotors on their website, and they seem to be close to 200/per

 

If you are wanting value for money I would go with option B with Porterfield R4-S pads (not R4 which are race pads) and then bed the new pads in properly as per the linked PDF, ie "....Typically, a series of ten increasingly hard stops from 60mph to 5 mph with normal acceleration in between should get the job done for a high performance street pad."

 

Glad to help.
I purchased from eeuroparts.com and received them a few days later. Here are the Brembo part numbers:
380mm front discs: T2R5940 Brembo 09D43311 09.D433.11
325mm rear discs: T2R5941 - Brembo 09D06111 09.D061.11

Total was $327 including tax and shipping.

 

The V6S came stock with the 325 mm rear brakes but it was fairly common for the brakes to be optioned up to the R-spec "super performance" ones with the 376 mm rear brakes so the OP should check if he has 325 or 376 mm rear brakes before ordering discs or pads.

 

Thanks!

I'll double check but pretty sure they were not optioned up, thanks for the tip!

 

Before trying anything else try taking the car through a car wash. First of all, a car wash is relatively inexpensive and is expedient. What I’ve found is the pressure wash removes unseen grime from the rotors that a wash with a hose in the driveway doesn’t seem to remove. If that doesn’t help, try the other suggestions.

 

I'm assuming the vibration only occurs during braking?

 

Yes the vibes are during braking.

For anyone who reads this thread, I only found one vendor who includes shipping for the Porterfield R4-S brake pads, and it just so happens they are the lowest priced options at 233.90 shipped.

https://www.lpiracing.com/

 

Yep, the same mob I bought my R4-S from some four years ago now. They were the cheapest then and it seems they still are.

 

I also got my porterfields from them.

 

Ref the comments on bedding in, note that Porterfield explicitly say not to do the bedding procedure for the R4-S. They say that their street pads are pre bedded and just drive gently for the first 100 miles and avoid hard braking down to zero if you can

On the rotors I'm skeptical of skimming them. You need to be sure the shop does it to a very tight tolerance. And you'll prob find you spend nearly as much as replacing with some quality rotors. Biggest $ saving is doing the work yourself. It's pretty straightforward.

Would ensure the hub is clean and rust free so the new rotors are definitely square and tight to the hub

I have the R4S on my XF after two sets of pads/rotors ended up pulsing (with drilled slotted). So I replaced with traditional rotors and the R4S and it has been perfect since.

 

Interesting.
When I fitted the Porterfields (R4-S) some four years ago now I didn't see or read of any advice from them or anyone else saying not to bed them in, so I bedded them in as I normally do - accelerate up to around 60 mph, brake hard down to around 10 mph (hard but not hard enough to invoke ABS), repeat 8 or 10 times until I can smell hot brakes and see some fumes, then do a "cool down lap" before coming to a complete stop or applying the EPB. Thing is after doing this I have had zero problems with the pads or the brakes, and zero brake shudder.
Maybe their advice not to bed them in came after I bought mine and maybe it was because of a change in pad material and/or pre-bedding?

 

I was surprised by the advice. So I checked with them directly. Also read on several other review sites that said the same thing - if you google you can see articles on an Aston forum, BMW etc and many others dating back 10 years

It was somewhere on their website although I can't seem to find that now

I'd suggest the OP clarifies with them directly what they recommend now. I did not bed them in given the direction I received and I've had no problems either. I don't see that bedding them can do any harm - just that they say it's not needed

 

That would be a good thing for me if they no longer need bedding in, I am dreading the next time I try to bed new pads in (long way off yet) as last time it made me nauseous just like sea sickness! From the repeated acceleration and braking that is, not the fumes.