300E 124 noisy brakes

[cumined]

Dear Readers
While braking--usually on a downhill at low speed we occasionally get a very loud scream sound from front wheel areas--has to be worn disc-pads we think. But on checking these they have plenty of meat and the car goes perfectly.

Can discpads do this from time to time? Humidity is almost zero here in South Africa. Just wondered if there is another explanation--or some way of stopping or minimising this noise.

Thank you

eddie