recently the brake pads on my 1989 300 E were replaced by a talented friend who has a number of older (than mine) mb's that he keeps in top shape. now sometimes the brakes make a grinding sound at the very end of braking to a stop and fell like they are letting go. also the braking sometimes has a pumping feeling and the abs light will come on for no apparent reason.

any suggestions for repairs would be greatly appreciated. thank you.

Somewhat common on many pre-1990 MB's, as faulty ABS sensors in the front will cause this problem.
Sometimes cleaning the debris from the sensors will help as they attract metal particles.

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Thank you, M.B.DOC for the tip to clean the abs censors. However, that didn't do the whole trick. At least not yet. Might it take a little while for the fix to work or is there another adjustment that would alleviate the grinding and slipping?
your advice is very much appreciated.

It may be just coincidence, but more likely your friend did something wrong. This is quite different from a braking system 'failure', so would be hard to diagnose by remote. Ask him to take another look at it.

Steve

Not quite the same car as yours, but the advise within this URL holds true in many cases anyway:

89 300ce ABS

any chance the caliper mounting bolts were not tightened to factory torque specifications? offer this thought in view of the fact that the abs speed sensors are a little on the expensive side so to speak. additionally, was the rotating disc under the abs speed sensor also cleaned?