Volvo Repair: groaning noise from brakes, v70 glt, sligh

Question
Got some moaning/groaning sounds from the brakes on my 98 V70 GLT.  The sounds only happen after using the brakes for awhile (city driving with 4 to 5 stops).  It goes away if you do not use the brakes for awhile like driving on the freeway, but it will come back once I am using the brakes several times.  The sound comes just right before the car comes to a complete stop.  It last for about 2 seconds.  It almost feels like the wheels are slipping pass the brakes, but there is no pulsating like the ABS activation.  Any help in diagnosis would be appreciated.  

Answer
if it is a loud rumbling sound it could be due to the type of rear pads and shims i has on them.the new replacement pads need a different shim.if it is a sligh moan sounding like the front brakes some noise like this is normal just as you come to a stop.