Gents,

Seems I hadn't visited the site in ages, lost my account, and had to re-register today. I've been searching the forums to see if anyone has had any similar experiences, but wasn't able to find anything.

The issue: Since I purchased my 2005 S-Type 3.0 (for the wife), it has always had an odd brake feel and paltry performance. The day I bought it, with 8900 miles on the odometer, it has:

- The first 1" of brake pedal travel does nothing. Nada. Zilch.
- After the initial brake travel, the brakes "bite" relatively hard.
- In a full-out panic stop, it feels as if there is NO brake power. Full pedal, and it feels like I'm in a 1990s econo-car. The pedal effort seems OK, there's just no power. My Mercury Marauder stopped better.
- Drive in the rain on the highway, and you're in for a real treat -- no braking until 1-2 seconds after the brakes are applied. (This one really caught me off guard.)
- There's always been some semblance of brake shudder when coming to a stop. Applying the brakes at 80 mph is really irritating; the whole car starts to resonate.
- The brakes used to squeal when coming to a stop, but that went away after about 20k additional miles.


What got me looking through the forums is that the rotors are glazed (I assume), resulting in varying degrees of brake shudder, and I was on a quest to see what others were saying about brake pads/rotors.


Has anyone else experienced this type of brake feel on their S-Type? Based on what others are saying in the forums, my experience is much different than most. After driving other cars for a while, and then jumping into the Jag, I always feel nervous with the first brake application.

Thanks!

 

U may need to check ur brake pads see if all is good, car has ABS brake system, could be the culprit, check brake fluid, maybe air in system.

 

Sounds dangerously faulty. Any good mechanic should be able to diagnose and fix it (it's a typical braking system) but you may find most will be too afraid (ignorance=fear) because it's foreign.

Here there are annual car tests (inspections) which would have caught it and required it to be fixed. The tests are a pain but have their very strong plus points. (Like, the guy behind you is likely to have a car whose brakes work.)

 

8900 miles is enough to maul rotors and pads if driven hard or the owner rode the brakes constantly. Or if your car was a dealer loaner or demo car and just got beat on.

Assuming you have not changed pads and rotors yet? If not, I would say it is probably time to do so, it sounds like you have a situation waiting to happen.

Also, you are on the 6 year mark, likely with the factory brake fluid. Definitely time to change it out. This can help the pedal feel for sure.

 

Jag's brake fluid renewal is every 2 years.

 

First step is an inspection of the rotors, calipers and pads. Lack of pedal for an inch or two sounds like at least one seized caliper.

I'll disagree for the time being with the 'blame the fluid' line of thought. Modern cars have 100% sealed systems that are not exposed to air unlike cars of the 60s and prior. No one has yet explained how air and moisture enters such a system if left undisturbed.

I wouldn't drive the car until the brakes are fixed, but that's just me.

 

Thanks for all the feedback, gents.

I bought the car -- a 3.0L Sport -- in Sept 2009 from the local Jag dealer where I lived at that time. (I traded my '04 Mercury Marauder w/65k miles.) The car was turned in after a 4-year lease, with only 8900 miles, and sold at auction. My dealer purchased it at auction, and I came along only a few days later and snapped it up. From what I can tell, the car was probably driven, only occasionally, by a female since there were a few small spots of nail polish on the shifter and steering wheel.

The brake feel has always been funky. The day I bought it, I recall thinking the brakes didn't feel quite right. (I've had a 2010 XF on a few occasions as a loaner; that car has GREAT brakes.) I initially just wrote it off as part of the car's character, but the delay in braking with wet rotors convinced me otherwise.

My inclination, prior to posting on the forum, was to get new rotors, pads, and flush the system with new fluid. You guys confirmed that. I appreciate the feedback that my car's brake feel is not typical for these cars. I've driven two other S-Types, and frankly, I don't remember what the brakes felt like.

 

Don't forget a caliper inspection especially for seized pins.

 

Driver's side rotor tells the story: The rotors are severely glazed. I'm guessing, by the visual check, that only 60% of the pad is contacting a "clean" rotor, with a clear indication that at one point, the pad was overheated and the car fully stopped. (There's a distinct pad imprint on the rotor.) This explains the poor performance and the horrible shudder at highway speeds.

http://www.flickr.com/photos/sheridandrbn/6278000725/http://www.flickr.com/photos/sheridandrbn/6278000725/ by http://www.flickr.com/people/sheridandrbn/, on Flickr

http://www.flickr.com/photos/sheridandrbn/6278521438/http://www.flickr.com/photos/sheridandrbn/6278521438/ by http://www.flickr.com/people/sheridandrbn/, on Flickr

http://www.flickr.com/photos/sheridandrbn/6277999839/http://www.flickr.com/photos/sheridandrbn/6277999839/ by http://www.flickr.com/people/sheridandrbn/, on Flickr





I was surprised to see clean brake fluid and that the car has stainless braided hoses to the calipers. Nice touch.

 

Sorry, I guess I've been off the forums too long. I can't figure out how to get a flickr.com picture to show up on my post. (I'm prohibited from posting attachments or editing my posts.)

 

In Flickr, grab BBCcode option.

Glad to see you got the brakes fixed!

 

It sneaks past the seals on the caliper pistons. I have to bleed the system on my race car a lot or I can end up with the water boiling if driven hard enough.

 

Mikey - It's not fully sealed, is it? Nearly, but not fully. 2 is overkill IMO but is the OE spec.

 

How would water (in the form of airborne moisture) sneak past the seals and not the air itself? Even if there was water in the OP's brake fluid, it would not cause any of the symptoms he's mentioned.

Apologies for the hijack, but this topic is yet another on my pet peeve list.

 

Thanks, joycesjag, for pasting the pictures!

 

Yes. Brake fluid is hygroscopic. Hygroscopic | Define Hygroscopic at Dictionary.com

I have another car that doesn't utilize brake fluid for the braking system and that fluid (LHM) is not hygroscopic. That car doesn't suffer the same issues. I've often wondered why modern cars are still using brake fluid.

Yes I agree that this is probably not his issue but something weird was done to his car's braking system. The changed brake hoses might be a clue that whomever did this was clueless.

 

Yes, I'm aware that DOT 3, 4 and 5.1 brake fluid is hydroscopic. The question is how does water (but not air) get beyond the seals to mix with the fluid, without any fluid leaking out.

No one seems to have a reasonable explanation.

So far the OP's brakes seem typical of one or more calipers with seized pins- very common on front and rear non-Rs.

 

Jeeze, if you leave a container of brake fluid open does it absorb water? Yes.

Does it absorb air turn and into a DOT3 soda? No.

The heat/cool cycling on the caliper pistons might have something to do with it as well?

Or ... maybe the Keebler Elves sneak in at night and **** in everyone's brake system reservoirs. I only know that they never leave any cookies behind for my cars ...

 

I agree about the seized pins.

Who says air can't get past the seals? So long as it gets pushed out again when you apply the brakes how would you know / why would it matter (I guess it wouldn't be a large amount)? But in any case all you need is a tiny amount of water vapour to get through and slowly the brake fluid stops working quite as it should. The typical brake fluid's very keen to absorb it.

 

I would assume the brake fluid reservoir must be vented. When applying brakes the brake fluid is pushed out, and since the reservoirs do not appear to be flexible it must be replaced with air. Hence the moisture gets in and the brake fluid boiling point decreases.