Just reading the XJ Technical Guide
The front and rear subframe each use two of these as well as two 'rubber void' bushes
Is a hydrabush full of liquid?

Yes they have liquid in them

I disagree--there are no hydraulic filled bushings on the x350 chassis other than the motor mounts. The "hydrabush" uses an internal nylon ball joint and is filled with grease. If they were filled with liquid they would have all failed at 20k miles when the rubber boots cracked.

Front lower control arm bushings are rubber type, as is 1 rear lower control arm and all 4 upper control arms. The "hydrabush" locations are at the bottom of the 4 shocks, 2 each at the rear lower control arms, and at the connection between the two lower front control arms. When a motor mounts fails/collapses, you will see a stream of hydraulic fluid from them (unvulcanised rubber).

People have been debating it for some time but the lower control arms use hydrabushes. Cut one open and you will see. I did just that.

Item 11 in the attached sketch from the jag x350 technical guide is described as a 'Hydrabush' mounting
Item 8 is described as a conventional bush mounting
Two of the rear subframe mounts are similarly described

Which lower control arms? I've seen all the bushings off my vehicle, none were fluid filled.

The subframe mounts may be, I've never had those apart or seen them up close. Would make more sense since the engine/trans mounts are hydraulic type.

Is it just another fancy name for a mundane part, or is it aptly named as is liquid inside????

A hydrobush (I think hydrabush is a trade name) is a bush which contains a viscous dampling liquid which flows around inside as the bush distorts, and they are used in applications which require a soft bush. The idea of the damping fluid is to stop the bush from oscillating rapidly (ie going 'du-du-du-du-duh') after a jolt, which is what a soft bush will otherwise tend to do. By the nature of being i) soft, and ii) having a fluid filled void within, hydrabushes are quite large.

Was just wondering now that someone brought it to mind.

Rubber is often viscous when formed, or so i thought.

Here you go

Those are most definitely not hydraulic fluid filled bushings. They are nylon ball joints with grease in them. The boots on those rip and the grease slowly works its way out. But they joint does not collapse. The large bushings on the rear lower arms are just rubber.

Two of the bushes, the two that lie in-line directly at right angles to the car, certainly are not hydrabushes; they are described as 'firm bushes' in Jaguar's description of the suspension (in '2012 Systems'). However it does say that the third bush is a 'soft bush' and moreover that soft bushes are hydrobushes.

Not sure there's anything left to add. Those are not ball joints. Not even close to a ball joint design. In thread 3, you say there are no hydra bushings in the X350. In thread 6 you acknowledge there are some. Now the part supplier is also wrong? Your argument is with the parts supplier then. I'm satisfied with what I've seen with my own eyes.

OK, here we go, (from my copy of Technical Guide XJ 2003.5.............

Page 5
Front suspension
"Hydrabushes incorporated in the rear mounting of the sub-frame provide added suspension refinement; the front mounting bushes are conventional rubber types"
and
"The lower control arm is a split design, which decouples to allow for improved bush adaption. A hydrabush is fitted to the forward lower control arm where it attaches to the subframe provides vibration damping."

Page 7
Rear Suspension
" The rear suspension is assembled on an isolated sub-frame mounted via four bolts to the vehicle body. Two hydrabushes incorporated in the forward mountings and two void-type bushes in the rear mountings provide optimum suspension refinement.

There is no mention of any other bush being of the hydrabush type.

I beg your pardon? In post 6 I said nothing of the sort. The engine mounts and subframe mounts are hydraulic. No suspension bushings are.

I question how you've seen with your own eyes that these bushings are hydraulic oil filled, because the simple truth is they are not. They are single-axis ball joints (not claiming they are the ball joints used on steering arms). They are solid in design (no deflection), lubricated with grease and provided with dust boots. You can buy a brand new one, unclip the dust boot and see the grease inside. No hydraulic fluid.

To the OP: these bushings (shown below) are described in the manual as "Hydrabush" which is a marketing term only. They are not hydraulic bushings. The failure mode of these is that the dust boots fail, grease mixes with road grime, and the bushing wears out and starts clunking. They are used on the rear lower arms, at the bottom of each strut, and between the two lower front arms.



The front lower arm bushing being described as hydraulic is either an earlier design or a misprint. These bushings are made of plastic and rubber, no oil.



Actual hydraulic bushings are rubber filled with a viscous fluid, and when those fail they will leak oil: