[W126 Coupe] ABS

[Jack Emery]

 420 sec/1986.
When I apply the brakes while rolling to a stop, the brake pedal kicks back 
repeatedly & the system groans till the car comes to rest. No big deal, 
except the stopping time increases & passengers ask me what it is. Also, the 
"ABS" graticule on the dash lights up, & stays lit until it decides to 
extinguish itself sometime later.
Is anything amiss here? It has occurred to me that because it is an old car 
with what is probably early ABS technology, I may be better off 
disconnecting the ABS system. Any suggestions, please?
Jack in OZ.