Troubleshooting
Even armed with the mathematical formulae above, performance braking is often a trial-and-error science. However, the theoretical background should narrow the possibilities, and many of the Web sites listed here contain Troubleshooting or FAQ sections to further zero in on what you need to make your disc-converted 4x4 stop on a half dollar without you owing any additional change.
So, math can help you match non-OE brake-system components and illuminate why your rig stops worse following a disc conversion. After all, the only thing that's worse than a 4x4 that won't start is one that won't stop.
A tubing bender is needed for most custom brake jobs. Even OE-replica replacement lines will likely need some fine-tuning to compensate for differences in component location between stock drums and disc conversions. | 
Adding valves to the system usually requires either custom making lines or splicing into existing ones. Hardware-store tubing cutters will work. | 
Most enthusiasts know that automotive brake systems use double-flared tubing ends instead of household-plumbing-style single flares. Double-flaring kits can often be borrowed or rented from a parts store. This high-zoot kit uses hydraulic assist. |
The double-flare seals in two places-on the outer lip and on the inner 45-degree bevel. Flaring is a three-stage process, using a female die for the "mushroom," a male die for the flare, and a third die to create the inner bevel. Remember to put the fittings on the tubing before flaring it. | 
Residual pressure valves prevent fluid from siphoning back into frame-mounted master cylinders, especially on hills. These valves typically have pipe threads and require adapter fittings to plumb into flared brake lines. | 
Before installing new lines, blow them out with compressed air. Clean any threaded distribution blocks that will be reused with solvent, a small brush, and compressed air. Then, reinstall the shipping caps (on mail-ordered lines) during routing to keep dirt out, and finger-tighten fittings and clamps. Carefully fine-tune any lines that don't line up, ideally with a bending tool. |
An adjustable proportioning valve regulates rear brakes' rise rate. Mounted in an accessible spot, the proportioning valve allows the system to be tuned to control weight-transfer-eliminating nose diving-during stopping. This SSBC kit includes a pressure gauge and fitting for more precise biasing. | 
Bleeding is a tedious-yet critical-part of performance braking. Brake troubleshooting should always begin by checking for fluid leaks and bleeding all four corners. This Phoenix Systems pressure bleeder quickens the job by forcing any air in the lines back into the master cylinder. If the bleeder isn't positioned at the top of the caliper, consider removing it from the vehicle, putting a wood block between the shoes, rotating the caliper to put the bleeder at the highest point, and then bleeding. | |