Rotor run-out.
Le Mans Master
Joined: Apr 2005
Posts: 6,349
Likes: 419
From: Seattle Area WA
Usually the brake fluid gets pumped full of air from the pistons moving in and out rapidly and sucking air into the system past the seals, therefore a soft pedal possible a pulsating pedal as well.
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
If the brake pedal on a C3 pulsates the 2 rotor surfaces are not parallel. A rotor that is parallel but has run out will wobble back and forth between the pistons and cause them to suck air in at the pistons, creating a low brake pedal.
Sometimes you even notice the fluid in the master is overfull due to air displacing some of the fluid.
Sometimes you even notice the fluid in the master is overfull due to air displacing some of the fluid.
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
Thread Starter
Drifting
Joined: May 2002
Posts: 1,546
Likes: 282
From: Back in Nebraska
I finally got my internet back on. Sometimes I think two cans and a string would work better. Thanks for the input. Maybe I don’t have a run out problem after all. I have a smooth brake pedal, no wobble, or pulsating. The brakes are strong and steady. Problem seems to be a constant worrling notice, goes away when I apply the brakes. Oh well, back to the drawing board.
