WILWOOD BRAKES TROUBLESHOOTING GUIDE

LOSE, YOUR PEDAL DURING RACE

Cause: Fluid boiling due to wet fluid or foot drag.
Solution: Flush out entire system with fresh Wilwood Hi-Temp° 570 racing brake fluid. Install dashboard brake light reminder.

Cause: Undersize brake system
Solution: Refer to the caliper web pages to select the correct caliper/rotor combination for your application.

Cause: Wrong size residual pressure valve
Solution: Use no larger than 2 lb residual pressure valve.

Cause: Incorrect or faulty master cylinder
Solution: Repair or replace master cylinder.

Cause: Leak in caliper or hydraulic lines
Solution: Check for leaks in caliper and lines.

Cause: Inadequate ducting
Solution: Reposition air ducts to center of rotor and caliper. (refer to Wilwood air duct technical sheet)

Cause: Pedal linkage failure
Solution: Check pedal assembly.

Cause: Excessive spindle deflection in corners
Solution: Check spindles for warpage. Install 2 lb residual pressure valve.

BRAKE DRAG

Cause: Bad master cylinder
Solution: Switch or replace master cylinder.

Cause: Incorrect residual pressure valve
Solution: Use no larger than 2 lb residual pressure valve.

Cause: Rotors warped
Solution: Replace rotors.

Cause: Calipers not square to rotor
Solution: Re-align brackets or shim calipers.

Cause: Tapered brake pads
Solution: Replace pads, check caliper alignment to rotor.

Cause: M/C has internal residual pressure
Solution: Remove residual pressure valve.

CAR WILL NOT STOP

Cause: Glazed pads and/or rotors
Solution: Grind and/or sand glaze from rotors.

HAVE TO PUSH TOO HARD ON PEDAL

Cause: Too large of a master cylinder
Solution: Refer to the master cylinder web pages to select the correct size unit for your application.

Cause: Not enough pedal ratio
Solution: Increase pedal ratio, see pedal web pages to select the correct pedal for your application.

Cause: Pedal mounted at bad angle
Solution: Master cylinder push rod should not be off more than 5° in any angle.

Cause: Wrong pad material for your applications
Solution: Pads must match rotor operating temperature range. See pad web pages to select the correct pads.

Cause: Frozen pistons in calipers
Solution: Rebuild calipers.

CALIPER LEAKS

Cause: Caliper seal old or dried out
Solution: Replace with new seals.

Cause: Nick or ding on piston or cut seal
Solution: Replace pistons and/or seals as necessary

SPONGY PEDAL OR BOTTOMS OUT

Cause: Air in brake system
Solution: Re-bleed the system.

Cause: Calipers not bled with bleed screws straight up
Solution: Unbolt calipers and hold with bleed screws in the vertical position.

Cause: Wrong size master cylinder (too small)
Solution: Refer to the master cylinder web pages to select the correct size for your application.

Cause: Faulty master cylinder
Solution: Replace master cylinder.

Cause: Calipers not mounted square to the rotor
Solution: Re-align brackets parallel to rotor, or shim caliper.

Cause: Calipers mounted equal to, or higher than master cylinder
Solution: Install 2 pound in-line residual pressure valve.

Cause: Calipers flex excessively
Solution: Check pressure. Do not exceed 1,200 P.S.I.

Cause: Pedal ratio too great
Solution: Reduce pedal ratio.

Cause: Excessive spindle deflection in corners causing piston knock-back
Solution: Install 2 pound in-line residual pressure valve. Check spindles for warpage.

OSCILLATION FEEDBACK IN PEDAL

Cause: Excessive rotor runout
Solution: Shim between rotor and hub/hat.

Cause: Pad material buildup on rotors
Solution: Change pads, clean rotor face.

Cause: Calipers loose
Solution: Tighten caliper mounting bolts.

Cause: Rotor faces not parallel
Solution: Re-grind rotor faces, or replace rotors.

Cause: Cracked rotors
Solution: Replace rotors. Refer to rotor web pages to select the correct rotor for your application.

Cause: Excessive front bearing clearance
Solution: Check for proper bearing size, or tighten the spindle nut.