I've got a 99 EM1, and when I push on the breaks there's a constant pulsing feeling. When I bought the car, the previous owner had installed slotted and drilled rotors. After I bought the car, my mechanic replaced the rear two rotors and all the pads because he said they were bad. I still have the slotted and drilled rotors on the front, but normal disks in the back. The pulsing became slightly less prominent after replacing the rear rotors, but it's still there. Any ideas?

 

Replace the front rotors. Forget that slotted and drilled **** - get proper blanks.

 

Why is it happening? I thought those brakes were good.

 

Brakes, not breaks. No, slotted and drilled **** is generally exactly that - ****. Different types of rotors have different applications. Your street-driven car does not need slotted or drilled rotors, and even if it did, the $40 eBay specials that are probably on there are absolute garbage.

It's happening because the rotors are warped. That's brake systems 101. Warped rotors = pulsating brake pedal.

 

I'm only 16 and wasn't the one who put the brakes on. But thanks for the input.

 

Okay since you are a young kid I'll play nice. As posted above, the rotors are warped and pulsating. The best thing to do is to get new rotors, preferably of good quality. If you can swing for OEM units, please do.

While there, replace the pads and inspect the calipers to make sure they are in good shape. Another thing to inspect while doing the brakes is the condition of the fluid and hoses. Make sure the fluid has a light caramel color and flex the hoses and check for over stiffness. If the hoses feel extra hard, might as well replace them.

 

Just had all the pads and lines replaced. It's all brand New other than the front rotors and calipers I believe.

 

^^
okay...?

So did u replace the front rotors too?

Im using wear-ever rotors and lasted me 4-5 years. 27.00ea

 

Yep, parts store rotors work for a normal DD. Brembo blanks are better, no denying that, but they aren't strictly necessary unless you're running real power adders (no, a CAI and exhaust aren't real power adders) or throwing it around a track.