Birelart Cylinder Master Cap

In your Birelart brake pump, this ring is the main pivot point between the control lever and the thrust rod. Its function is twofold:

1. Eliminate the game: It allows a "fat" movement without sidebeat. Without it, your brake pedal will have an unpleasant dead race ("blur" effect).

2. Self-lubrication: Generally composed of sintered bronze impregnated with oil, it is designed to operate "dry" or with a minimum of lubricant, thus preventing the premature wear of the steel pivot axis against the aluminum of the lever

The 22SR EVO piston is a precision piece. Unlike appearances, it's not just a metal cylinder. It is machined with extremely low tolerances to allow the joints (cups) to slide without flee while generating a constant hydraulic pressure.

• The evolution "EVO": It guarantees a surface finish (polishing) optimized to reduce friction and increase the lifetime of the cups.

Do not replace the seals one by one if your pump is "spongy". The complete kit allows you to leave on a healthy basis.

• Type content: The kit generally includes the piston, the primary cup, the secondary cup, the O-rings, the maintenance circlips and sometimes the protective bellows.

• When to use it: As soon as you see a loss of constant pressure, an internal leak (the pedal drops gently under pressure), or after a long wintering where the liquid could crystallize.

BirelArt 22SR pump clips

Why is this spring critical?

Although it is a simple room, the internal spring of the 22SR pump filled a major safety function:

1. Return of the piston: It guarantees that the piston returns to the "rest" position after each braking. If the piston does not return completely, the circuit does not fulfill correctly by the tank, creating a soft pedal or braking that "drag" (drives that heat).

2. Maintaining pressure: It ensures a constant pre-load for the joints (cups) remain in place.

3. Reactivity: It allows the pedal to go back immediately as soon as you relax the foot.

On a 22SRR pump, you find O-rings at different locations (tank hose entrance, fill cap, sometimes as guiding joints).

The most important point: The material. The seals used in hydraulic braking must imperatively be in EPDM (ethylene-propylene).

• The danger: If you are using a "standard" O-ring (often in NBR / black nitrile bought in DIY store), it will swell, disintegrate and pollute your circuit in less than a few hours in contact with the Brake fluid DOT 4 /5.1.

The Liquid tank for brake pump 22SR is a spare part of origin manufacturer (Original Freeline / Birel Art). This jar is specially designed to power the master cylinder (brake pump) model 22SR that equips the braking system of the group competition chassis Birel 

On your 22SRR pump, the "pin" (pin or pivot axle) of 5x15mm is the piece that undergoes shear forces at each braking.

• Function: It serves as a hinge for the lever that operates the piston of the pump.

• Why a specific room? Unlike a metal rod cut at the right time, this pine is in Treated steel (tempered). If you are using a "soft" stem of hardware, it will dig and deform in a few tours, creating an important game in your pedal (the famous "blur" at the beginning of the race).