93 xj40. when i start my car, the abs warning ligt comes on and
flashes 6 times taking aprox 30 seconsds? then will go out. also,
the red brake light comes on and remains on untill the abs light
goes off. as soon as i start to drive less than 100 feet, the abs
light will return, and stay on the entire time i am driving. I
know the abs is not working correctly because when i was trying to
drive in snow, the front brakes were locking with the slightest
pressure on the brakes. any ideas on what it might be, or where to
start looking? brake fluid level is ok.

 

I'm not going to pretend to know a whole lot about XJ40's since I've had mine for a whole 3 weeks but I need an ABS Brake Accumulator on it. Jaggraveyard.com describes the system and testing as follows: "The Teves Anti-Lock Braking System as installed on Model Year 1990 through 1994 Jaguar XJ6s and all XJS with Teves ABS. the System has demonstrated both high reliability and excellent durability. It is considerably more than just an anti-lock braking system; it also provides the power-assisted boost for the master cylinder. It is however, quite non-conventional in comparison to other contemporary ABS designs. Instead of the ubiquitous vacuum assist booster for the master cylinder, it uses a hydraulic boost provided by a small electric motor driven pump. To prevent continuous pump operation... WHICH WILL KILL YOUR $1300.00 PUMP, high-pressure hydraulic fluid is stored within an inert gas filled ACCUMULATOR. Whenever the driver applies the brakes, this stored hydraulic energy is used to boost input pressure to the master cylinder. To Check Your Accumulator : Run car at 2000+ RPM for 30 seconds. Shut motor off and turn key on to activate VCM. Pump pedal slowly, 3 count intervals, check the number of times before the low brake pressure warning light comes on. A fully charged accumulator will go 9 pumps. 4 pumps necessitates system check out, probable accumulator bladder failure."

Is there a black ball attached to your brake master cylinder? That's the accumulator. I only get a brake light and ABS light when applying the brakes firmly but they both go out almost immediately. My mechanic said I would need a new accumulator before I bought the car. Try the test above and see what happens. That would be my guess.....