Hi,
I've always been unhappy with the brake pedal feeling. System is all good but never got the accurate consistency.
Braking system is in good condition. I just think it is normal for a 25 year old conception car.
Lastly, I fit a Brembo R perfo system : all new Brembo calipers, new rotors and pads, new braided hoses.
Pedal feeling is still the same.
I would think it may be imoroved by upgrading servo or master cylinder or flexion somewhere between the pedal and master cylinder.

Don't know if someone experienced an upgrade for that?

 

Hi jeje,

You may want to have a look at john's youtube channel about the XK8/R : https://www.youtube.com/channel/UCT2...vbQNEdQ/videos

He has just done a series of videos about upgrading his brakes, very interesting. I also agree with you about the pedal feel, same "problem" here on my 99 XKR i find the pedal throw to be way too long and you really have to push strongly to make it brake consistently.

Compared to my other cars where a slight push of the brakes has immediate effect, i find it to be less confortable to use.

Cheers,
Ryan

 

I suspect they were not like that when new and thus something is perished/worn/...

 

Yeo!
I have thought about worn servo, booster and so on but looking on forums, it is a common reported default.
I would think this feeling is an engineer choice or a default in the design somewhere from the pedal box to the master cylinder...???

 

They were like that from new, and it is either hated or an acquired taste. They are very "Ford Like" as some other Ford/Lincoln vehicles I have driven have the same type of throw, but if you drive something from the Japanese market like a Honda, etc., the brakes are so touchy they feel gradual push will lock them up instantly.

I'm a taller guy, etc., so I almost prefer the way they are, but understand how some would prefer the tighter feel.

 

Long throw brakes are actually a plus over the overly twitchy passenger car feel.

With a long throw you can more easily modulated braking when you are feeling a little racy.

 

Agree with you, the possibility of many degrees of subtlety as opposed to the car always tending to instant panic.

Rental car last week was a Passat, DC beltway. Unpleasantly overreactive in high speed dense traffic. Should have driven up in the Jag.

 

Long throw brake on X100 is OK when you think that X100 is a comfortable 90's GT, dedicated first to US market. That not means brake power is not there too and is not efficient. That's a totally different thing.
No problem with that.

My concern is just that this setting looks like wrong with my perception of the car. So, just trying to to change this feeling and get something more accurate from my point of view.

 

There are several things, including
1. The amount of pedal force/throw required to reach a given braking level relative to car mass.
2. How much the brakes/rotors grip at a given braking condition. This depends on many things.
3. The ABS braking logic The distance to lockup/ABS depends substantially on the road, tires, suspension too.

Given a properly operating brake booster/system, if you can push down enough to get to lockup/ABS (3), then nothing is particularly wrong with 1. As noted above, 1 is quite different between the xk8 and the Passat, for example. However, standard stopping distance 60-0 was measured by Motor Trend at 118 ft for the stock XK8, not Porsche 911 levels of earth shattering jarring of teeth, but not especially bad. That said, I doubt that I could do this on any road around here with my new tires/at regular weight, having played with the ABS system.

You can change 2 with brake pads/rotors/calipers/suspension/wheels/tires, but it seems unlikely you will get Passat levels of response without modifications to the rotors/pads/calipers and probably wheels/tires/suspension/downforce. Suspension and downforce seem like things you more easily modify by buying a different car. Also best to take everything out of the car, including the passenger and rear seats, and have the tank be on E since the Passat weights about 300 kg less. Even then, I don't think you could ever get to Porsche 911 levels of teeth jarring stopping deceleration. Maybe a deployable parachute...

You can change 3, by removing it, but you likely cannot (or should not) modify it.

 

Long post...
I too have the same view. I too have a Ford from the era..'the wheelbarrow' a trusted '01 F150XLT, 160k, NAPA service center fresh power brake booster 600 mi on. Its' feel has always been superior to my XK8 stock system at 70k. Just not a fan of asymmetric calipers.

Contemplating the 4x Brembo conversion. It will included vented, slotted-not drilled-StopTech rotors perhaps. maybe NRS pads rear and street performance fronts, brand TBD: braided lines as you. I will add solid caliper attachment, comprehensive front-susp rebuild, and sub-frame mounts. while retaining the present 69k master and booster. Current system is strong, performing indeed... 'entirely adequate'. I'm dismayed to hear "it's still the same over-servoed feel". Ugh

Recent experience-high relevancy
Twelve months ago, my 1-series NA too was 4x asymmetric Ate' (say ahtay) oem 62/38 proportioning valve, it too entirely adequate. The intercooled twin t-bo 135i/335i... my 'Brembo donor'...uses 63/37 balance and 6-pot (996-era) front Brembo, 4-pot rear. As 135i power is more mighty, the weight advantage of the NA car is near 100 kilos. While I'd not expect the XK8 to be like my 1er result (greatest torque-reducing, stomach thrusting decel those having experienced it, never to forget...) it would not be rewarding if 'it felt just as before' the $$$ transplant. Say it ain't so

Keep us informed when a solution is plausible, please.

 

Gee! jeje...Until you told me that my Brakes were no good....I thought I had the best Brakes in the World....I've been using Brembo Brakes since my 2003 XKR and just love'em….Now tomorrow I will not know what to do since my Brakes have gotten so slow to react...Hope I don't have a problem on the way to work!

Billy Clyde

 

Careful in The Wild...

 

You have the best brakes in the world
Maybe not the best servo or master cylinder or fixing system, in my mind

 

JeJe,

Aren't you cute?

I made it to work and back just fine without any problems...The Brakes? They worked great and seemed to be more efficient as the day went on! Thanks for bringing this to my attention!

Billy Clyde in Houston

 

,JeJe,

Not trying to be a smarty pants at all.....but after all, the XKR with the Brembo Package is more than sufficient for what the XKR is made for! It is not a race car by any means but makes for a great little Road Car with plenty of go power and with the Brembo's, plenty of Stopping Power...If you want to use it as a Race Car, you really need to do much more to the Suspension, Engine and Brakes. If I was using the Car on the Track, I wouldn't have bought the Coupe in the first place.....So, I have driven my XKR over 100,000 Miles with a smile on my face and Happiness in my Heart.....and will continue to be a happy ole boy doing so!

Thanks for your help and take care of yourself young man!

Billy Clyde