Hydraulic Brake Fluid Reservoir Cap Assembly ?️

Keep your stopping power safe and consistent. This cap seals the master cylinder tank, protects brake fluid from air, dust, and moisture, and keeps pressure balance stable so your pedal feel stays firm and predictable. Built to OEM-grade specs for a precise fit and reliable sensor function.

Why this part is needed ?

Brake fluid is hygroscopic and easily contaminated. A tight, durable cap blocks water and debris, prevents vapor loss, and supports the level warning switch. This reduces corrosion, boiling, and spongy pedal issues.

How it works ?

The threaded body and fuel-resistant gasket create an air-tight seal. A flexible diaphragm equalizes micro-pressure as the fluid expands and contracts. Many versions house a float or reed level sensor that signals the dash lamp. A calibrated vent prevents vacuum while stopping splash-out.

What happens if it’s broken ⚠️

Cracks or a hardened gasket lead to seepage, dark fluid, air ingress, soft pedal, brake/ABS warning lights, and corrosion in the master cylinder. In extreme cases, pedal travel increases and braking distance grows.

Pro tips ✅

Inspect the seal and diaphragm at every fluid change. Clean the neck before installation. Hand-tighten only; do not over-torque.

Compatibility

• M30