Hi,
I've had my '97 XK8, which I love, for almost a year. I was driving home this evening and had to stop in a hurry. The thing is, my brakes suck. I'm always amazed at how awful they are. The pedal is soft and I always have the feeling that there is a film of oil on the rotor. There isn't, I know, but that's how they feel. I've had several mechanics from different shops try them and shrug and say that that's normal and it's how they all feel.
The brakes on my old '86 Mercedes 300E are way better and have much better stopping power.
Why do my Jag brakes feel so crappy? Is there a way around this? Any fix? Right now the Jag is equipped with Jaguar stock rotors and pads.
Thanks.

 

An improvement is to fit stainless steel braided hoses, which improves braking performance & eliminates the spongy feel of rubber hoses.

 

When was the brake fluid last flushed?

Air and moisture are two big contributors to a soft or spongy pedal.

Graham

 

Your brakes are not up to manufacturer's spec. Possibly the pads/rotors are glazed with pad material. I'd consider having the rotors gone over with an abrasive pad and replacing the pads with new.

Bleed and flush the fluid as a first step as recommended by Graham.

 

Thanks, guys.
I did have the brakes flushed and all the fluid replaced. At least, I was told that this work was done but the British Sports Car place I went to proved a bit iffy on some other things they did, so who knows??
I will take your advice and replace the brake lines with braided ones.
As for the brake pads, the ones on the car are fairly new and are the factory ones. I've always used Brembo pads, rotors and calipers on my Merc. Is there a better choice for the Jag than stock Jaguar stuff?

 

You can get the Brembos for the jaguar as well. The XKRs came with them stock.

 

That's a pricey upgrade. In the $2200.00 range? Just asking.

Bruce

 

My XKR has the optional brembo brakes. When I bought the car the front brakes caused pretty bad vibration above 50mph speeds. I ended up ordering new pads and rotors. Since I don't have airtools (yet) I was not able to replace the rotors so I ended up doing just the pads for now. What I noticed while doing the job was that the inner pads on both sides did not move freely inside the brake assembly. It was a bit of a fight to get them out. Also the inside of the rotors were not as much worn as the outside. I started thinking this is probably the main reason for the vibration as most of the brake force was applied only on the outside. The more you push the pedal, the more the pads would bend the rotor causing the vibrations. What was even bigger surprise to me was that the new pads (can't remember the make) were even tighter fit (even after cleaning everything properly). I actually had to remove quite a bit of material (the metal, not the pad material) lenght wise from the pads to make them fit and to be sure they would move freely. After completing the job the brakes work about seven trillion percent better than before. As a bonus the vibration is almost completely gone. I still have to replace the rotors the next time I'm working in that area... Just thought I'd share this as it had a huge impact on the braking performance...

 

I have a set for sale for less

https://www.jaguarforums.com/forum/p...xkr-xk8-54781/

 

Hi,
Normally the brakes on XK8 should perform well, and the pedal should not be soft.
A soft or spongy pedal can be caused by different things.
However, the most common cause is "swollen" hoses or small air bubbles in the brake fluid (after master cylinder). Sometimes the seals in the master cylinder gets worn and can then "suck in" a small amount of air every time the pedal is released. This can be diagnosed by bleeding the system using a clear plastic tube on the bleeding nipple. It will then be small air bubbles visible in the tube when bleeding, that will not disappear when continuing bleeding the system.
The "soft" pedal in tease cases is caused by compression of the "bubbles" in the system when braking. (fluid without bubbles cannot be compressed)
A bad "swollen" hose will also expand when applying brake pressure. This can be seen looking at the hoses when pressing the pedal hard. The hose will look "pregnant" (expand) if this is the case.

Good luck solving your problem!

 

Just an FYI.
Not the same as you problem, but I had a car that pulled to right when braking. I tried everything. In the end the left front brake line had swollen internally and cut off flow to left brake.

 

Not just air or swollen hoses. I drive lots of differant same model Jags and see one thing over and over. people(women mostly) that brake lightly and often glaze the crap out of the pads and rotors and once they are they never brake like normal again. Im talking not enough brake grip to activate the ABS and this is NOT normal for a Jag that IMO has pretty good stock brakes. You can clean somewhat and restore better braking by warming pads with light braking, then cleaning with a few panic stops, does even better if doing a panic stop in reverse, you can feel them improve on grip after a couple times. Ive used alot of after markets and until I used a set of EBS reds I felt the stock braked the best. I changed mine to reds and where I used to get brake fade on high speed stops trying to time a set of lights on the way to work. I never did again with the reds. Theyre low dustin and very controlled even braking. I switch to them on every vehicle I own because I like them so much more. Just a thought

 

T-6,

I do think the peddal is a bit soft and over boosted, but with the XKR's Brembos (and an aftermarket set of drilled discs), my car has unbelieveable stopping power. I have to think that there is something amiss in your system. The XK8's standard stopping power shouldn't be "that" much less than mine.

 

I can't really comment on any of these brake problems, but I can say that I have been greatly impressed and pleased with the braking power of my 2005 XK8. For braking, my XK8 is better than any other car I've driven.

 

I am upgrading my XKR to brembos, so have the original xkr brakes for sale, they work well. I'd sell the entire package, pads, rotors, calipers, caliper mounts and the flexible brake lines for $450 if you are looking to go that route.

 

I had mine for over 10 years now, it's a '97 also. Odometer shows 81k km now and It's in top shape. I do my own maintenance (I mean everything), it's a hobby for me. It's my 11th Jaguar in 35 years. They are great cars to work on. My wife has a VW EOS and a Sorento for winter. My other car is a '07 Cayman. Brakes have alway been soft but acceptable and over the years, I tried many things to fixt it without much luck. Rotors are perfect no glaze and I installed ceramic pads last year (same as the other 3 cars). Last December I purchased Goodman SS braded lines and installed them last month. Situation is WORSE now. The feel has changed yes but pedal travels all the way now to get decent braking. I bleeded the brakes first with a vacuum tool, then went to pumping engine running and not, traction aid on or off. There is no more air coming out of the nipples and I went through at least a quart of fluid. If I give it one pump before braking, I feel an improvement. I'm thinking of changing the master cylinder, always thought it might be the culprit. But I don't read much about them failing. And why was-it acceptable BEFORE I changed the flexible lines, I say? When I switch from the Porsche to the XK8, I feel like I have no brakes. Bleeding the other cars is like a walk in the park...

Changing brake lines or switching to Brembo to fix the soft pedal WONT work in all cases. Not in mine for sure.

 

You may be onto something there.

There was a post in the last couple of days where a member installed EBC Reds and had to file the ends of the brake pad backing plate as you describe.

It would not be surprising if many of the plates are being supplied from a single source and they got it wrong ... or the addition of that nice red paint is enough to bring out the problem.

If you combine that with people who just knock them in with a bigger hammer rather than figuring out what the problem is ... then you have a problem.

 

I brake like a woman

I am also pretty sure that I glaze the rotors on this car even being careful to roll out of hard stops so that the rotors cool a bit before coming to a full stop.

The problem is that in moving from a Supra Turbo, my braking habits have not changed. Yet, the Supra never had this problem through three sets of pads. Never turned the rotors, just did pad slaps. I guess I'll have to go after the suggestion made by JagTheRipper and pull the calipers off to check the pad clearance.

The actual braking performance is just as good as on the Supra, if not better. Aside from the vibration. The feel however is different ... more progressive and cushiony as perhaps desired by Jaguar engineers. But, I have no doubt that they will stop the car.

I hate getting into the ABS ... the feel and noise are annoying, and it means I've made a mistake.

 

I now have the rotors replaced too and the braking power is just awesome now No more vibrations too

 

Do you have a source for stainless steel brake lines for an XK8? AFAIK they are only available for XKRs.