Jaguar X-Type Spongy Brakes

I don't know if it's normal for that model or not. What I do know is that a pressure seal failure in a m/c can allow fluid to leak back into the reservoir, which would agree with the symptoms you describe. Might be interesting to see if the fluid level rises as the brake pedal sinks. Mike.

Did you buy from a main dealer? If so, ask to try another one.

If not, go to a main dealer (NOT in your car, obviously!) and ask for a test drive...

Chris

Any servo asssisted car will exhibit the same thing. When you pump the pedal, you use up the stored vacuum for working the servo, so the pedal goes firm. Then as the vacuum builds up again, the servo assistance gradually increases, causing the pedal to sink down.

As for the OP, I'd say it's quite normal. Quite alot of cars (especially bigger ones) have quite a bit of pedal travel. It's just the way they're designed, so that should the servo assistance fail, the driver still stands a chance of stopping the car.

In news:efretk$bjc$ snipped-for-privacy@north.jnrs.ja.net, mlv wittered on forthwith;

I've driven thousands of miles in X-types and never known that. They're not wonderful, but the symptoms you've described sound pretty scary.

I suspect its a fault.

I have tried the brakes on other vehicles (including a Mondeo V6 - the Jag is only a Mondeo wearing a different hat) and I cannot reproduce the 'sinking pedal' effect.

Once past the pre-travel, the brakes on the other vehicles come up firm and solid. The Jag brakes remain soft and spongy. If the Jag brakes were firm and solid, I wouldn't feel the need to pump them.

I am definitely not impressed with the feel of the brakes, although they do seem to stop the vehicle OK.

I actually have much greater issues with the awful gear change and AWD transmission, which is rough, noisy and agricultural. That subject will probably be my next posting :-)

The vehicle is booked into the Jaguar Main Dealer Thursday of this week for investigation. I will be given a loan vehicle, which I hope will be another X-Type so that I can make my own comparison.

Either way, I have asked for a report in writing. My vehicle is still under Jaguar Warranty.

The dealer did say that they had another X-Type in with the same 'sinking pedal' problem. They said that they replaced the whole master cylinder/brake servo assembly and it made no difference.

Hmm. Unless the OP has swopped from a Morris Minor I'd say he must be used to servo brakes. And spongy brakes with long pedal aren't the norm on every 'bigger car' - not that I'd describe an X-Type as a 'bigger car' anyway.

Dave Plowman (News) ( snipped-for-privacy@davenoise.co.uk) gurgled happily, sounding much like they were saying :

I haven't got a single car with a brake servo. I've only ever owned one car with a brake servo.

Try pumping the pedal with the engine stopped, then hold the brake down and start the engine. Any car with a servo, the pedal will sink, and if it doesn't, then something's not working how it should.

Chances are, the jaguar will be running a far bigger servo, so the vacuum takes that bit longer to build up, which also has the effect that the pedal is softer.

There are vehicles with soft pedals as normal. A prime example is an Iveco Daily 65C (that's 6.5tonne worth of lorry), which has an extremely soft pedal, and is quite a scary sensation the first time you drive them.

Well, there you go. They work OK. What else do you want?

Did you expect anything different from a mondeo in disguise?

Is 'soft' a deliberate design feature then? Why would any manufacture deliberately design a braking system that is soft and spongy?

What makes the brakes soft? I would have thought that once the pads were hard against the discs, the pedal would be solid, unless there is a brake fluid or vacuum leak, or air in the brake lines. What part of the braking system allows the continuous compressibility?

Confidence in the braking system. Soft with excessive travel doesn't do it for me.

Well, quite frankly, yes, I did, My previous car was a Mondeo V6 Estate (102,000 miles) that had the nicest gear change of any car I have owned. The new owner commented on how sweet and smooth the gearbox and transmission were. I wish the Jag was as good.

Some are basically designed for left hand drive, and the pedal linked to the master cylinder by mechanical means on RHD versions. This usually results in a springy feel to the brakes.

Apart from the above, there are flexible hoses connecting the discs to the rigid pipework - needed to cope with suspension movement etc. These can sometimes expand slightly under pressure. Other possibilities are slight flexing in the pedal or mounting, etc.

I collected my X-Type Saturday morning.

Rather predictably the brakes are "normal" for this vehicle.

The soft, 'spongy' feel seems to be a consequence of the poor conversion from the 'favoured' LHD design, to RHD. The servo and brake master cylinder remain on the left-hand side, whilst the brake pedal moves to the right-hand side. Presumably whatever mechanism transfers the pedal movement across the bulkhead has too much torsional movement, hence the unpleasant 'spongy' feel.

But it gets worse, much worse. One of my other major gripes is the rough, 'agricultural' gear change. It transpires that the 3.0 X-Type has a CABLE gear change. The Austin Maxi lives! Cables - no wonder the gear change is so poor.

If I had known it had a cable gear change, I would never have purchased it.

Maybe Jaguar like cables. Maybe the connection between the brake pedal and brake master cylinder is another cable. That would explain a lot...

mlv ( snipped-for-privacy@jet.uk) gurgled happily, sounding much like they were saying :

Sorry - let me get this straight...

1. You purchased an X-type with a manual box...?
2. You purchased an X-type without apparently driving an X-type...?

Or did you just not notice the brakes and gearchange on the one you test- drove? In which case, why are you accepting the fobbing off as "normal, Sir"? What about the brakes on the dealer's demo car (which is almost certainly an auto, I presume)?

A car that is regularly praised for its slick, precise gearchange is the Ford Focus. It uses cables...

Chris

And if he thinks an X-type cable change is bad, he needs to try a transaxle Alfa gearchange.

Nothing wrong with a well designed cable change. Even BMC got that right with the Austin 1800. Due to the later poor design of the Maxi one, they also re-engineered later 1800s to have a rod change - which after a very short time was vastly inferior to the old one.

There's no need for a rear gearbox change to be poor - indeed some of the finest changes ever are on this layout.

:-)

I know it's the obvious thing to say, but surely a decent test drive would show these things up?

Before I commit the sort of dosh the OP has, I hire a car as close as possible to what I'm going to buy.

Chris

There's lots of linkages, cables and rods.

They're fine when all set up with new bushes and adjusted properly, but as they wear they become a real PITA.