Brake Question Please Come In.
Thread Starter
TECH Fanatic
iTrader: (27)
Joined: Mar 2002
Posts: 1,167
Likes: 0
From: Huntersville, NC near Charlotte
Brake Question Please Come In. I did a GP on some crossdrilled/slotted rotors with hawk hps pads and have about 4k miles on them. Ever since I had the put on my pedel seemed to have some rebound to it if I hit the brakes a lil harder than normal driving. I did break them in btw. They've seemed to have gotten worse and I thought it was cause they needed to be bled. Can the rotors get put on backwards(pic below)? If so would that have anything to do with them pulsating at al(if mine are backwards)l? No ses lights on at all either. Thanks for any help.
Teching In
Joined: Sep 2009
Posts: 15
Likes: 0
Some cross drilled/slotted rotor mfg's have "handed" rotors. If you put the left side on the right side (& vice versa), you could minimize the cooling capability and cause the rotor to warp from too much heat. Warping will result in pedal pulsation.
Also, always use a torque wrench to tighten the lugnuts. An impact wrench will cause uneven loading on the rotor which can also lead to runout issues (warping).
On a regular rotor, the best thing to do is get a dial indicator and check the runout of the rotor while it is still on the car but it is tougher with a cross drilled/slotted rotor. When I used to "cut" rotors years ago, I could put a rotor on a brake lathe and visually tell if a rotor was warped.
One last thing...you could just have a cheap rotor. I have seen new rotors with way to much runout out of the box which will get worse as you put miles on it.
Also, always use a torque wrench to tighten the lugnuts. An impact wrench will cause uneven loading on the rotor which can also lead to runout issues (warping).
On a regular rotor, the best thing to do is get a dial indicator and check the runout of the rotor while it is still on the car but it is tougher with a cross drilled/slotted rotor. When I used to "cut" rotors years ago, I could put a rotor on a brake lathe and visually tell if a rotor was warped.
One last thing...you could just have a cheap rotor. I have seen new rotors with way to much runout out of the box which will get worse as you put miles on it.
Staging Lane
Joined: Mar 2009
Posts: 71
Likes: 0
From: Ohio
If the rotors are not warped check the caliper. If you compressed the piston when you did your rotor swap(if you did pads too) you may have wedged a piston against the seal or knocked the dust boot off of its guide. The dust boot can either get wedged or cause moisture and dust to get into the brakes. If so you may not have the right amount of force to stop your car. As the pads wear down, it will feel like it could be loosing braking power.
Most Aftermarket Cross Drilled rotors could be directional by the brand. Check your suppliers website or give them a call to make sure you have them in the right direction. If your autoX or doing long trips might be why you have brake fade too.
Most Aftermarket Cross Drilled rotors could be directional by the brand. Check your suppliers website or give them a call to make sure you have them in the right direction. If your autoX or doing long trips might be why you have brake fade too.
