Upgrade Motorsport - Spherical Bearing Master Cylinder Brake Bleeding Guide

Overview - Master Cylinder Brake Bleeding Guide

This guide provides the correct procedure for bleeding the brakes and tightening specifications for the Upgrade Motorsport Spherical Bearing Mount Master Cylinders (available in 0.625" and 0.7" bore sizes).Proper bleeding and torque application are critical for achieving consistent pedal feel and reliable braking performance.

Preparation

Tools and Materials Required:

• Suitable brake fluid (DOT 4 or racing specification as recommended by your system)

• Brake bleeding kit or vacuum bleeder

• Box-end spanners (10mm for bleed screws, 14mm for fittings)

• Torque wrench

• Clean rags and catch container

• Copper washers (new, if removed during maintenance)

Fluid Port Specifications

Port Type	Thread Size	Torque Setting	Washer Type
Fluid Inlet Port	M10 x 1	17–20 Nm	Copper washer
Fluid Outlet Port	M10 x 1	17–20 Nm	Copper washer

Ensure that all fittings are clean and free from debris before tightening. Over-torquing may damage threads or cause sealing issues.

Brake Bleeding Procedure - Inlet & Outlet Clearly Marked with Arrows

1. Secure the Master Cylinder: Ensure the master cylinder is securely mounted with the pushrod and spherical bearing correctly aligned.

2. Fill the Reservoir: Fill the brake fluid reservoir with clean brake fluid. Keep it topped up throughout the process to prevent air entry.

3. Initial Bleed (Bench Bleed if New):

   • If the master cylinder is new, bench bleed it before installation.

   • Inlet & Outlet Clearly Marked with Arrows incorrect fitment will cause DAMAGE.

   • Connect short brake lines from the outlet ports back into the reservoir.

   • Gently depress the piston by hand until no air bubbles are visible.

4. System Bleeding:

   • Start with the brake furthest from the master cylinder (typically rear right), then move to rear left, front right, and finish with front left.

   • Open the bleed screw and depress the pedal slowly. Close the screw before releasing the pedal. Repeat until no air bubbles appear.

   • If using a vacuum bleeder, follow the manufacturer’s instructions to draw fluid through the system.

5. Final Check:

   • Ensure firm pedal pressure and no visible leaks at the fittings.

   • Top up the reservoir to the correct level.

   • Recheck torque on all M10x1 fittings (17–20 Nm).

Post-Bleed Inspection

• Check all connections for leaks under pressure.

• Ensure the pedal has a consistent and firm feel.

• Test the braking system at low speed before competition or road use.

Important Notes

• Use only clean, fresh brake fluid from a sealed container.

• Replace fluid regularly according to manufacturer or racing team recommendations.

• Dispose of used brake fluid responsibly.

Safety and Installation Disclaimer

• Upgrade Motorsport products are designed for use in competition and specialist vehicles that vary significantly in size, weight, configuration, and application.

• The responsibility for correct installation, suitability, and safe use lies entirely with the purchaser and/or installer.

• Upgrade Motorsport and any member of its team accept no legal liability or responsibility for any accidents, incidents, damages, personal injury or death proven to be caused by or related to the use of any component supplied by Upgrade Motorsport.

• These products are installed in diverse motorsport and automotive environments, and it is the sole responsibility of the end user to ensure compatibility, compliance, and safe operation.

• All installations should be carried out by a qualified professional.

For More Information

Visit: www.upgrademotorsport.co.uk

Upgrade Motorsport – Precision-engineered hydraulic solutions for race-winning performance.