Dave- the 500E had ASR and ABS, as such, it has a different ABS pump than yours, unless you have ASR as well.

Pure ABS W124's don't have a bleed-procedure other than a high-pressure bleed.

ASR equipped W124's have a bleed-nipple on the rear back of the combo ABS/ASR pump.

:-) neil

1st picture: 400E without ABS (lower right corner)
2nd picture: 500E with ABS/ASR lower right corner)