XJS ABS

[cml]

I've a '94 XJS, the first heavy properly powerful car I've ever owned. I am finding that the ABS is kicking in quite a lot. This means that either I am driving beyond sensible limits (quite possible ) or it is cutting in rather early. I don't go for manic braking as a rule. I know it is very heavy, which can't help. Both front tyres are nearly new before you ask.

Is the system adjustable?

Is it known for being very 'helpful'?

What is the general opinon of XJS brakes?

[Trooper2]

Have you changed tire/wheel sizes or installed tires from a different manufacturer or are you still running OEM size and brand?

If you've made any changes there the ABS module may need to be reprogrammed. Even tire pressure differences can cause ABS missfires (unwarranted ABS activation).

[cml]

Nope, I've made no changes to the standard kit.
I'll check the tyre pressures. I've been going for 30psi all round.

[Trooper2]

cml, here is a generic list of concerns that might cause ABS misfires/over sensitivity:
ABS- a wheel speed sensor may be out of sync due to....a damaged wheel speed sensor reluctor ring, a loosely mounted wheel speed sensor, an intermittent short, open or high resistance in a wheel speed sensor circuit, a damaged or faulty wheel speed sensor, uneven road surfaces.

Base brakes- ( we've covered tires), loose wheel bearings, glazed brake shoes or pads, grease or brake fluid on the shoes or pads, a faulty brake pressure control valve, or mis-adjustment of the rear brakes.

I can't answer your other questions regarding the XJS as I have know experience with the model yet.

Maybe if I keep the thread alive an XJS ABS guru will make an appearance.

[Bobfrance]

I find mine can kick in quite readily, though normally only at slow speeds when approaching junctions in the wet (where you find petrol and diesel deposits).

You could try asking on the J.E.C. Bulletin Board
www.jec-xjs-forum.org.uk/xjsbb2/index.php
(You may need to be a club member though, I can't remember - give it a try)

At least the ABS on the Jag is incredibly smooth - I just get a soft clicking noise when mine is working


Bob.

[xjs_man]

Mine (1992) did exactly the same thing.

(At least) one of your sensors is on the way out, to be followed closely by the master cyl, if my experience is anything to go by ;-)

Don't panic though - neither is hugely expensive (though I don't remember precisely how much they were)