Q: |
Does Wilwood have a kit for my muscle car, hot rod, or street rod? |
A: |
With over 250 bolt-on kits, Wilwood manufactures brakes for most front and rear applications, and we're constantly adding to the list. |
Q: |
What is the basic difference between a drag kit and a pro street kit? |
A: |
Drag kits use solid steel rotors
(or optional drilled rotors) and yield high brake torque, yet are
very lightweight. They are engineered to the absolute minimum in
rotating and unsprung weight, where a single stop at the end of
a drag run is what's required. They should not be used for multiple
stop applications. |
Q: |
Do bolt-on kits require any alteration to the spindles or rear axles? |
A: |
Usually not. In a few cases, minor modification may be necessary. |
Q: |
Do installation instructions come with Wilwood kits? |
A: |
Yes. With the exception of certain custom applications, all Wilwood kits include step-by-step installation instructions. Please note that brake kits and components should only be installed by experienced mechanics with a good understanding of brake systems. |
Q: |
Can I use my stock wheels? |
A: |
Most kits require use of a 15" wheel or larger. Review our dimensional drawings for actual brake caliper clearance requirements. |
Q: |
What bolt patterns and stud sizes are available in Wilwood bolt-on kits? |
A: |
Front kits which include Wilwood aluminum hubs have ½"
studs. With a few exceptions, hubs are manufactured to accept both
5x4.50" and 5x4.75" bolt patterns. Hats
used in front kits are generally drilled to fit over the original
OEM studs. |
Q: |
Why are some rotors drilled or slotted? |
A: |
Rotors are drilled
to reduce rotating weight, an issue near and dear to racers searching
for ways to maximize horsepower. Drilling diminishes a rotor's durability
and cooling capacity. |
Q: |
What type of brake pads should I use? |
A: |
Wilwood has the right brake pad for your application. Polymatrix brake pads, including Compounds "A", "B", "C" and "D", cover every high performance and racing need: from top end drag race to short track stock car. We also offer specialty pads such as "Cold Stopper", which has been engineered for low dust, low noise street rod and pro series vehicles applications. |
Q: |
What master cylinder should I use with Wilwood brakes? |
A: |
The goal is to select a master cylinder system that supplies
sufficient fluid volume to provide a firm, responsive pedal, while
generating enough pressure to stop the car comfortably. |
Q: |
Do I need to use a Residual Pressure Valve? |
A: |
Residual pressure valves maintain a nominal amount of pressure in the brake system to alleviate fluid from draining back towards the master cylinder and causing excessive pedal travel. Use 2lb. RPV's when the master cylinder is mounted below the level of the disc brake calipers to prevent brake fluid from draining back down into the master cylinder. Use 10 lb. RPV's with all drum brake applications to offset return spring tension. |
Q: |
When do I use a proportioning valve? |
A: |
A proportioning valve is a pressure reduction device. It is typically installed in the rear brake line to reduce braking efficiency and compensate for premature wheel lockup; a result of incorrect front to rear brake bias. An adjustable proportioning valve permits incremental adjustments to fine tune brake bias. |
Q: |
What size brake lines should I use? |
A: |
Use 3/16" steel line wherever possible. Use flex line only where necessary. |
Q: |
Will stock rubber brake lines work with Wilwood Brakes? |
A: |
Yes, but they require 1/8" - 27 NPT adapters to fit the calipers. We recommend use of high quality -3 or -4 braided stainless steel flex lines as replacements to the stock rubber lines. |
Q: |
Why can't I get the caliper to fit over the rotor on my rear axle kit? |
A: |
You may have the wrong offset drag hat or pro series bracket. Our kits include brackets and hats that are designed to fit on unaltered OEM axle offsets. If you have a narrowed rear end or custom axles, something may have been altered from the original specification. Please check our Housing Flange Identification Chart for proper housing end and offset information. |
Q: |
What type of brake fluid should I use? |
A: |
Wilwood's Hi-Temp 570 is the best choice. Other fluids are available, but may have a substantially reduced boiling point, which can cause fluid boiling and brake fade under moderate operating conditions. DOT 5 Silicon Fluid is not recommended. In addition to being easily aerated which leads to a spongy brake pedal, it is not hygroscopic, which permits moisture accumulation in the brake system, lowering the boiling point. Note: To maintain a high dry boiling point and maximum performance, change the brake fluid often, especially after high heat cycles. |
Q: |
How do I bleed the brakes? |
A: |
Make sure all calipers have bleed screws facing upwards to fully evacuate air from the system. Wilwood calipers with internal fluid passages and four bleed screws (two on each end) require only the upward facing bleed screws to be bled. Start bleeding the bleed screw farthest from master cylinder (typically the right rear caliper outboard half), and work towards the one nearest the master cylinder. |
Q: |
What is a crossover tube? |
A: |
A crossover tube is the external tube on a caliper that transfers fluid from one side of the caliper to the other. Some calipers have internal fluid passages and do not require crossover tubes. |
Q: |
How do I do to eliminate a spongy pedal? |
A: |
A spongy pedal can occur for a number of reasons: air in the line, misaligned caliper, incorrect caliper/master cylinder bore combination and more. See our complete Troubleshooting Guide for a more thorough list of causes and solutions. |
Q: |
Why does my pedal "fade" or "goes away" after I've warmed up my brakes? |
A: |
Old brake fluid is the main cause of this problem. Brake fluid deterioration occurs from heat cycling and absorption of moisture. As brake temperatures increase, the old fluid boils, causing the pedal to fade. See our "lose your pedal" section of the Troubleshooting Guide, and make sure you are using fresh Wilwood Hi-Temp 570 DOT 3 racing brake fluid. |
Q: |
I have a hard pedal, but the car won't stop. Why? |
A: |
Common contributors to "hard pedal, won't stop" issues are oversized master cylinder bore and inadequate pedal lever ratio. See our Troubleshooting Guide for more complete information, and make sure you have Wilwood Quick Check Pressure Gauges available to assist you in evaluating the problem. |
Q: |
Why do my brakes drag? |
A: |
Brake drag can be caused by a failing master cylinder, incorrect use of Residual Pressure Valves, mis-aligned calipers or a badly adjusted brake pedal. Brake drag can cause excessive pad and rotor wear, and a spongy pedal due to fluid boiling. Our Troubleshooting Guide has more helpful hints. |
Q: |
Why does my pedal pulse when I apply the brakes? |
A: |
Brake pedal pulse or oscillation can be caused by excessive rotor run out, rotor faces out of parallel, excessive bearing clearances or inadequate suspension components. Solutions to these issues and more can be found in our Troubleshooting Guide. |
Q: |
Why do my brakes clunk or squeal when I apply them? |
A: |
Some of the noises can be minimized, others are an unavoidable
result of the incredible friction levels obtained in today's high
performance racing brake pads. |
Q: |
Where can I get replacement brake pads for my Wilwood calipers? |
A: |
Wilwood has a worldwide dealer network that stocks and sells replacement parts. Check your phone book for the local high performance speed, hot or race shop, or e-mail Wilwood with your location, and we will provide a referral. |