Nissan Repair: brakes and sqealing, timing belt tensioner, water pump bearing

Question
first, my passenger side brakes sqeal when i am in stop and go traffic. i have checked the pads and they are good but the hub cap is covered in brake dust. i think it may be that the caliper is bad but i don't know. could it be the rotor? also, i get a sqealing chirping sound around the front of the engine. the belts are relatively new they are tight. i have recently replaced the water pump and the alternator and i am lost with this one. could it be one of the other pulleys have bad bearings? i tried belt dressing and that didn't work. any help would be great. thanks. oh...by the way the car is a 1999 Nissan Altima.

Answer
Hi Eddie -

The dust on the hubcaps are normal. I wish they would invent "dustless" brakes! The noise is caused by vibration of the pads in the caliper. What you need to do is remove the caliper and pads, clean them out with brake cleaner, use "Disc brake quiet" to adhere them to the piston, and grease on the edges of the pads where it contacts the caliper. That should take care of the noise.

As for the squealing, I could be one of the idler pulleys, alternator bearing, or water pump bearing (could be even the timing belt tensioner). You can check this a couple ways. Remove each belt one by one and run the engine. When the noise goes away, you can pinpoint the source. If the noise still exists after all belts are removed, it is probably the timing tensioner. The better way is to get a mechanic's stethoscope (long crewdriver with your ear to one end will do the trick as well). Touch one end to the alternator housing, the center of the idler pulley, and see if you can hear vibration or noise. You are doing this while the engine is running, so be careful -

hope this helps -
aloha
calvin