On my 1998 ML320 with 115,000 miles I am getting a clicking sound when braking at low speed. It seems to be coming from the front portion of the vehicle. It may also be there at higher speeds but if so is be masked by the additional noise.
I thought it was the plastic portion of the brake sensors grabbing. I have replaced the front rotor and pads with no difference in the noise.
You do not hear it with the windows up, but it is very noticable when they are down.
Has anyone else had this noise or have any idea what it might be?

1998 ML320 115,000 miles

Say HELLO to your new sets of torsion bar bushings!

They are worn, dead, and needs to be replaced.....

Thanks for the answer.

I was afraid I was going to get something related to the transmission and big bucks.

I will get them replaced.

Thanks,
Wayne

1998 ML 320 117,000 miles

I forgot what they replaced but when he brought to inspect, they found the problem to be serious, and wouldn't let him drive the car home, and gave him a lift home... You should be very careful, you may have the same problem as my friends, I believe he spent $1,500 to fix it..