Wilwood Tandem Chamber Master Cylinder (1-1/8” Bore)
WIL260-8556
The Wilwood Tandem Chamber Master Cylinder – 1-1/8" Bore is designed for hot rods, street rods, classics, resto-mods, and custom vehicles using power-assisted brakes. This lightweight aluminum master cylinder combines a clean appearance with the fluid capacity and pressure control needed for larger multi-piston brake calipers.
A high-pressure die-cast aluminum body houses an integral dual reservoir with a 2:1 primary-to-secondary chamber volume ratio. The 1.10" piston stroke provides ample fluid displacement, while a slotted mounting flange and outlet ports on both sides of the bore simplify installation and brake line routing across a wide range of domestic vehicle and custom chassis applications.
Includes:
- (1) Wilwood Tandem Chamber Master Cylinder
- Integral Dual Reservoir
- Dual-Sided Outlet Ports with Plugs
- Pushrod Not Included
Specifications
| Specification | Details |
|---|---|
| Manufacturer | Wilwood |
| Master Cylinder Type | Tandem Outlet |
| Bore Size | 1-1/8" |
| Piston Area | 0.970 in² |
| Piston Stroke | 1.10" |
| Chamber Volume Ratio | 2:1 Primary to Secondary |
| Reservoir Capacity | 8.0 oz Primary / 4.8 oz Secondary |
| Reservoir Volume | 14.4 in³ Primary / 8.7 in³ Secondary |
| Body Material | High-Pressure Die-Cast Aluminum |
| Finish | Bare Aluminum |
| Weight | Approximately 3 lbs |
| Outlet Configuration | Dual-Sided Front and Rear Ports |
| Brake Assist Compatibility | Vacuum or Hydraulic Power Assist |
Fitment
| Fitment Requirement | Compatibility |
|---|---|
| Brake System | Power-Assisted Brake Applications |
| Brake Assist Type | Vacuum Booster or Hydraulic Assist |
| Mount Flange Spacing | 3.22"–3.40" |
| Common Bolt Patterns | Chrysler, Corvette, GM, and Ford Mustang Applications |
| Vehicle Type | Hot Rods, Street Rods, Classics, Resto-Mods, and Custom Builds |
Fitment Notes
- The 1-1/8" bore is intended primarily for power brake systems.
- The slotted mounting flange accommodates mounting patterns from approximately 3.22" to 3.40".
- Outlet ports are located on both sides of the bore to provide flexible brake line routing.
- For disc/drum systems, use a 10 lb residual pressure valve in the drum brake circuit.
- A pushrod is not included with the 1-1/8" bore version.
- Proportioning valve kits, brake lines, adapters, and vehicle-specific mounting components are sold separately.
- Verify pedal ratio, booster compatibility, caliper piston area, and brake system volume requirements before installation.
FAQ
1. Why is the 1-1/8" bore recommended for power brakes?
A larger master cylinder bore moves more brake fluid with less pedal travel but requires greater pedal force. A vacuum booster or hydraulic assist system provides the additional force needed to operate the larger bore while maintaining a manageable pedal effort.
2. What does the 1.10" piston stroke provide?
The longer stroke gives the master cylinder enough available fluid displacement to support larger multi-piston calipers and custom brake systems. Actual pedal travel will depend on caliper volume, brake adjustment, pedal ratio, and system setup.
3. What is the benefit of the 2:1 reservoir chamber ratio?
The larger primary chamber provides additional fluid capacity for the brake circuit with greater volume demand, which is commonly the front circuit. The smaller secondary chamber supports the lower-volume circuit while keeping the master cylinder compact.
4. Does this master cylinder eliminate the need for a proportioning valve?
No. A proportioning valve may still be required to balance front and rear brake pressure for the vehicle's weight distribution, caliper sizes, rotor sizes, and tire traction. Wilwood proportioning valve retrofit kits are sold separately.
5. What should be verified when selecting a master cylinder bore?
Match the bore size to the total caliper piston area, pedal ratio, brake assist system, vehicle weight, and desired pedal travel. A bore that is too large can create a hard pedal, while a bore that is too small can produce excessive pedal travel.
