# Brake master cylinder

> The brake master cylinder converts force on the brake lever or pedal into hydraulic pressure and sends it to the caliper.

- **Also known as:** Fren pompası, Fren ana merkezi, Master cylinder
- **Turkish term:** Fren merkezi (fren pompası)
- **Category:** [Master Cylinders & Calipers](https://motorsikletparcasi.com/en/category/master-cylinders-and-calipers)
- **Page:** https://motorsikletparcasi.com/en/glossary/brake-master-cylinder

A master cylinder consists of a fluid reservoir, a piston and a seal kit. The front master cylinder is usually on the right handlebar and the rear one near the right foot pedal. In Turkish it is also called "fren pompası" (brake pump).

## Symptoms of a problem

- A spongy lever that comes back to the bar – air in the system or an internal seal leak
- The lever slowly creeping towards the bar under pressure – worn piston seal
- Leaks from the reservoir cap

It can be rebuilt with a repair kit; always bleed the brakes afterwards.

## Related terms

- [Brake caliper](https://motorsikletparcasi.com/en/glossary/brake-caliper): A brake caliper uses hydraulic pressure to move its pistons and press the brake pads onto the disc.
- [Brake fluid](https://motorsikletparcasi.com/en/glossary/brake-fluid): Brake fluid is the high-boiling-point fluid that carries pressure from the master cylinder to the caliper.
- [Brake pad](https://motorsikletparcasi.com/en/glossary/brake-pad): A brake pad is the friction-lined part that the caliper pistons press against the brake disc to slow the motorcycle.

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- Source page: https://motorsikletparcasi.com/en/glossary/brake-master-cylinder
- Last updated: 2026-10-09
- Türkçe sürüm: https://motorsikletparcasi.com/sozluk/fren-merkezi.md
- Site overview: https://motorsikletparcasi.com/en/llms.txt
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