The Pump should run for 30 - 45 seconds on start up (pressurizing system). On instrument panel, two lights should be on at start up, red Brake light (same one is on when parking brake is up), and yellow ABS light. The red Brake light will go off once the system is pressurized, yellow will stay on until you've driven a short distrance and all wheel sensors have checked out OK. If neither light is on at start up, the system is disabled. Check under driver's seat for a series of relays & fuses. If there was a problem the previous owner may have disabled it instead of fixing. The ABS controller is under the passenger seat. Connector is known to suffer from corrosion, clean & snap it in place a few times to clean terminals.
Parts are very expensive, $1200 for master cylinder/valve block, $800 for pump, $250 for accumulator (new prices)
Take a look here to get an idea of the system design & pitfalls:
http://www.rangerovers.net/repairdetails/abs.html
