be aware that by disabling your ABS system, should you get into an accident, and should it be discovered that your ABS is not functioning, you could land yourself in a great deal of trouble.
At the very least, you're going to have to go through a great deal of time and money proving how the non functioning ABS was not the cause.
I'd be a little more of a hard-ass with your dealer and say that the trial and error approach is not acceptable if you have to keep replacing parts that are not the cause.
They should be diagnosing the problem...not guessing and making you buy parts ad nauseum without solving the problem. if they want to go the route otf trial and error, fine, but on THEIR time. THEY try it out and see if the problem is resolved. if it's not, put the original parts back in and proceed to the next possible cause.
Find another car, like yours, and see if you can swap out the ABS computer. See what the result is. if the car behaves normally, it's the computer. if it exhibits the same symptopms, it's something in the braking system. you have new front sensors and cleaned splines. all that's left are 1) rear sensor or 2) wiring.
'94 W124.036 249/040 leder; 8.25x17 EvoIIs
'93 W124.036 199/040 leder; 8.25x17 EvoIIs, up in flames...LITERALLY!
'93 W124.036 481/040 leder; euro delivery; 8.25x17 EvoIIs
'88 R107.048 441/409 leder; Euro lights
'87 W201.034 199/040 leder; Euro lights; EvoII brakes; 8x16 EvoIs - soon: 500E rear brakes
'70 R113.044 050/526; factory alloys; Euro lights