Hello all,
I believe I have a problem with my '04 XJ6 brakes. I would say serious, although other people that drove it might disagree.
First of all, after I've bought it 2000 km ago, I've checked all the fluids, and the brake one looked totally awkward, with what it looked to me like some water and brake fluid mix-up.
But the car drives fine, and if I drive normal, the car acts normal, brakes as expected. Many things on my head, and I totally forgot about this until about a week ago, when the outside temperature got higher (it's summer in southern hemisphere), and requiring to brake harder than before the pedal seemed to sink badly, so I've pumped it once and grabbed properly. Getting home, I've checked the fluid in the reservoir, and it was obvious this time that the liquid was dark with transparent spots in it. Grabbed my $10 one man bleed kit with a transparent pipe and a small container and pulled out about 250ml of fluid. For half of it was obviously there were transparent spots being pulled out.
At the end, the fluid was just a little bit under the low marker. Took the car for a short drive to the closest petrol station, and while in a ramp, the low brake fluid message appeared on the dashboard, showing that the sensor at least is doing it's job. It disappeared as soon as the ramp ended.
Refilled to max with some DOT4 Castrol. Afterwards, there are still some of this water droplets spots, but much less, and the fluid is not that dark anymore.
Having it refilled, I've started some tests:
1) Normal brake, normal speed, car brakes normally.
2) Full emergency brake, car seemed to brake faster, but not as fast as you would expect. Pump it twice, doesn't change the outcome.
3) Depressing the pedal very slowly it sinks without almost any change in vehicle dynamics. Like the brake wouldn't be depressed at all. -> so here I start believing I have some air in the system
4) Depressing the pedal very slowly, and about at the middle of the distance, pressing harder as a normal brake, the car starts braking normally. -> I'm not sure about the air in the system anymore...maybe just water?

Now, the question is: what are the most common parts that fail in the X350 brake wise? I know for a fact that the rear brakes squeak like a pig when braking slowly. But is, for example, the master brake cylinder, a common failing part?

I know I must replace the whole fluid, but I'm not keen on doing it yet, as I'm trying to find a method of removing all of it without actually circulating all that water through the whole system. I know water and air affects the brake system badly, and I don't want any of that near my callipers, although it might be too late anyway. Currently searching ebay and aliexpress for a vacuum brake fluid replacement tool of some sorts. Any pointers are appreciated.

Regards from the sunny side!

 

A common place for brake fluid to leak (slowly and can cause air in the system) is the brake caliper seals. If you look at the brake caliper then if it is covered in a greasy wet substance then your seals are leaking brake fluid onto the caliper and the assembly. Other placed to check is obviously the brake lines themselves up to the brake servo. I'd just check all the lines for leaks right to the calipers. If your seals in the calipers are leaking then there are rebuild kits so that you do not have to buy new calipers.

 

Hello LittleMan,

My ¢2 is to avoid from "over engaging", save or take a chance of...
Check immediately your brake disc, (C2C8354 - for non supercharged vehicles) , all wheels brake pads (C2C23786),
to keep on sleep safe and comfort, replace all necessary brake fluid, (2 x tanks/bottles C2D34402), you can use this
Car Hydraulic Brake Bleeder Clutch (https://www.aliexpress.com/item/3290...27424c4dX8Osh4)
and read/youtube.com about the accurate process to do it...

Update for P/Ns at: https://parts.jaguarlandroverclassic.../brand/jaguar/

Keep driving safe.

 

Oh, thanks guys!
I’ll have a look in the following days.
Thinking of using this time ATE SuperBlu DOT4 fluid, as I’ve used it successfully in the past, and it’s an obvious change from the old fluid to the new fluid, when is coming down the lines.
Anyone had any experience with the blue ATE in the XJ?

 

I really think any DOT 4 is better than water contaminated fluid. What I do is;
1.Vacuum out reservoir with the mighty Miteyvac.Refll with fresh fluid.
2. Power flush with power flush tool. Cap fits right on fluid tank. Start on passenger rear, driver rear, passenger front, and finally driver front. Flush a liter at first wheel and a 1/2 liter at each wheel after. Use a catch can and watch displaced fluid. All bubbles and water should be long gone before moving to the next wheel.
3. Overfill reservoir and use Miteyvac to suck out to full mark on the tank.

This technique should get any crap out of the ABS pump too. The ABS system contributes to spongy pedal. Also the inconsistent feel. You can flush until NAPA runs out of fluid and still have softness with ABS brakes.