Brakes Pulsing?

[B/STOCK]

I have a 2000 with 26,000 very easy miles on it. Last year I put on the chrome wheel drum covers and a new wheel and tire package from Tire Rack. The tires and wheels are perfect and role true to 150MPH the top speed I tested the package on. I put the wheels and tires on and torqued them (with a quality wrench) properly at 100ft lbs. The only thing I did not do myself is loosen the rear rotor to slip the covers under. I told the mechanic (a Corvette guy) to torque the main rotor bolt to 175 ft. lbs. which it calls for. After about a 1000 miles I am getting a slight pulsing when I brake. I am extremely easy on brakes so I know a @25K they rotors and pads should be fine. I did the same thing on my C6 about two years ago and it has been fine for 4k miles. The only difference is the rear rotor on the C6 did not have to be loosened. Any other reasons for this pulsing? Thanks Mike

 

[Clive]

Other Cause?

If everything was done correctly, a warped rotor can cause pulsation of a brake pedal. Have the rotor run out checked.

 

[B/STOCK]

If everything was done correctly, a warped rotor can cause pulsation of a brake pedal. Have the rotor run out checked.

I really don't feel a Vette with 25k very gentle miles should have a warped rotor. Whats a rotor out? Thanks

 

[Clive]

Rotor Run Out

Hi B/Stock;

Brake rotors take a lot of heat in just general driving alone. It is possible, probably slim, one could have warped, but in my experience, it's usually happens on the front as they take most of the braking power.

Run out is where an object like a rotor or a wheel assembly has a slight "bend" in it and instead of rolling true the side deviates a little. To simplify things, imagine a flat piece of aluminum like a pie plate. Bend it slightly. Instead of it being flat it now has a slight deviation from being flat. If it was rolled, the slight bend would be the run out. It can be measured with a special gauge that is set to zero and the rotor turned by hand on the car. The gauge can measure the deviation or run out.

My apologies if this explanation was too simple, it's just that I do not know how in depth your mechanical skills/knowledge goes. It is certainly not an attempt to make you seem foolish as I do not know everything myself.

 

[SANOLS1]

I replaced my rotors at 15K miles and installed the BAER Eradispeed two piece Rotors that are drilled and slotted. Once I hit 40K miles on the car (25K since I installed the Baer brakes) I noticed a slight pulse as well. I checked the runout on both front rotors and found they had .0015 and .002. runout. I figured it was better to turn them now and take off minimal material than wait until they got worse and the possibility of being too far gone to turn. I pulled all four and had them turned for $65 bucks. Added new pads and all is well once again. It doesn’t take much to notice a pulse. Good luck!