So i just installed new rotors and pads on my volvo 940 on the rear. Now they squeal worse than the old rotors and pads. its such painful high pitched squeal everytime i brake. whats wrong here? im confused.

 

What brand/type rotors and pads did you install? Did you use anti-squeal shims?

 

Keep in mind that 70% of your braking is done by the front brakes. It might be possible that your front brake pads are worn. And if this is true, you need to replace those ASAP, because they will damage your rotors. But if you're sure it's the back brakes that are squealing, you need to be sure that you sanded down the surface in a"cross-thatched" style, to prevent the squealing and apply brake cleaning solvent to the contact surfaces. If you feel a pulsation or "wobble" when you slow down, that is an indication that your rotors were not trimmed along the contact surface before they were manufactured. Some manufacturers do that for you, but in other cases, you need to do that yourself or take it to a car shop and have it done.

 

some commin reasions brakes squeal. if the edges on the leading and trailing edge of the pad arent cut at an angle, you have no shims behind the pads and no lube on the area of the pad that contacts the caliper. i know this since im ASE cert. in brakes and i see it all the time, just some comin mistakes. If it is the back for sure and you have new rotors and pads, make sure the pad edges on the leading and trailing edge are filed down to a 45degree angle so that there isnt a sharp edge 90degrees to the rotor surface ( i know its hard to explain). make sure you have shims between the back of the pad and the caliper, and make sure there is lube in there as well, not alot but engough that everything can slide around without binding. also when you put the new rotors on did you spray the rotor with brake clean? if not, there is a chem. that they use when packing the rotors so they dont rust, you need to wash that off.

 

woops. thanks for the advice! well i didnt see any shims in the pad packet, and i didn't put any grease on the back of the pad. il have to check the rotors and see if there filed down already, where do you take them for that? i got pads and rotors from VIP auto parts...not sure of the brand im just a college student so i couldn't really get the high test brake parts... i got some brembos off ebay but they were for the wrong volvo model il post a pic....im sure someone else could use them.