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Author Topic:   Brake Lock Up
Dirt Newbie

Total posts: 1
posted July 22, 2003 11:43 PM  
Has anyone encountered a problem with total brake lock-up after about 20 laps. The car is a 2003 J&J with titanium rotors on the left front, right rear, and inboard. We use wilwood calipers and a wilwood 1" master cylinder. What occurs, and it has happened twice while leading main events is a total lockup of all brakes which stops the car dead in its tracks.

After the first incident, we replaced the master cylinder, two-pound residual valve, checked all rotors for run -out and replaced all calipers and pads. We returned to our original set up some 15 races ago.

The perplexing problem is we had no problems during the first 15 races and it started out of the blue. We thought it could be brake pedal geometry but that has not changed.

Has anyone got any ideas?



Dirt Freak

Total posts: 376
posted July 23, 2003 09:44 AM  
Perhaps your floating inboard rotor on the LR is swelling up due to heat and locking itself to the axle. We had to add a shim to the 2-piece rotor hub to keep it free to travel on the splined axle.

You might change your brake fluid as some types will boil causing pressure within the system. This actuates the brakes as pressure builds...just like stepping on the pedal. Maybe even look at another brand of brake pads.

Hope this helps...


Dirt Freak

Total posts: 205
posted August 02, 2003 03:30 AM  
I have heard of this happening, and even witnessed it once or twice. I would also suggest a complete brake fluid replacement with total new fluid. personally, I have always had good results with motul , or wilwoods exp 600 (i think its called). The other possibility is the fact that TI. rotors are capable of so much heat, they actually seem more trouble that they are worth at times. I run alum. on left front and right rear and a 3/8 steel inboard, I have plenty of brakes ( I think ) and with the exception of goin thru the small pads fast, no real problems. I have also heard of the pistons sometimes seizing in the caliper, but that is rare.
When they lock up, can you identify where they lock up, or is it total system lock throughout the braking system. the other suggestion is free the car up so ya dont need the brakes...j/k

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