The cup (or lip seal) is a wear part. Its role is to transform the pressure exerted by your foot into hydraulic pressure into the pipes.
Symptoms of fatigue: "Spongy" pedal (which goes down to the floor), liquid leakage at the bellows (cap), or braking loss during high heat phases.
The material: These joints are EPDM (ethylene-propylene-diene monomer) to withstand the brake fluid. NEVER USE STANDARD JOINTS hardware stores, they will disguise in a few minutes in contact with the liquid.
| Feature | Specification |
| Mark | Birelart (original room / freeline) |
| Compatibility | Birelart Type CL / 22S / 22SR Pumps |
| Material | EPDM (High Chemical Resistance) |
| Kit contents | Primary cup, secondary cup, O-rings |
| Use | Complete renovation of internal tightness |
The montage of the cups is the most delicate operation of Karting mechanics.
Surgical dismantling: Clean everything before opening. Only one metal dust in the cylinder striped the wall and makes the new kit unnecessary.
The cylinder inspection: Before mounting the joints, pass your finger (clean) in the body of the pump. If there is any stripe or corrosion, the kit will not hold. It will change the pump body.
The sense of the lip (crucial): The cup has a flat side and one side with a concave lip.
The lip must always be pressure oriented (Inside the pump, piston side).
If you mount the cup upside down, the liquid will pass behind the piston and you will not have any brakes.
Lubrication: Never climb a "dry" seal. Dip the new cups in clean brake fluid (DOT 4/5.1) before inserting them.
"The classic trap is the insertion in the pump body. The trick: The cup is flexible and tends to turn around or to pinch while inserting into the cylinder. My Pro Council: Use a small rounded plastic tool (no screwdriver!) To accompany the joint lip when entering the bore. And once mounted, do not go back immediately on the kart: press the piston by hand to check that it comes back alone and there is no hard point. "
Q: Does a 22SR joint kit is identical to the CL ?
A: Attention, Birelart has several types of pumps. Always check the reference engraved on your pump body or the diameter of the piston (often 19mm or 22mm). Never force a seal that seems a little too big or too small.
Q: Why do my cups swell after a few weeks ?
A: It is the classic sign of pollution of the liquid. Either you have put non-compatible liquid (mineral oil type), either you have used grease not compatible with the brake fluid. Only the special "brake" (ATE or similar) or the brake fluid itself must touch these joints.
Q: Do I have to change the piston at the same time as the joints ?
A: If the piston has traces of oxidation (black stings), change it. A piston pique will act as a file on your new cups.
You touch the most critical system of your kart. To finalize your intervention:
[Liquide de frein (DOT 4/5.1)] (Always use a new can).
[Pince à circlips] (To access the piston without marking the accommodation).
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The cup (or lip seal) is a wear part. Its role is to transform the pressure exerted by your foot into hydraulic pressure into the pipes.
Symptoms of fatigue: "Spongy" pedal (which goes down to the floor), liquid leakage at the bellows (cap), or braking loss during high heat phases.
The material: These joints are EPDM (ethylene-propylene-diene monomer) to withstand the brake fluid. NEVER USE STANDARD JOINTS Hardware stores, they will disguise in a few minutes in contact with the liquid.