The brake master cylinder is responsible for distributing fluid from the reservoir to the front and rear brake systems. The fluid reservoir actually sits on top of the master cylinder with hard metal brake lines running out of it. There are a few places where the master cylinder can leak and cause a spongy or soft brake pedal. The inside has several pistons with o-rings and seals that can fail and allow brake fluid to escape. Likewise, the external metal lines also have o-rings where fluid can seep out or let air/moisture in.
This is an OEM replacement brake master cylinder that fits many E28 5 series and E24 6 series. If your original BMW brake master cylinder has failed, this is the high quality replacement you need.
only for cars with ABS
This item fits the following BMWs: 1982-1988 E28 BMW 524td 528e 535i 535is M5 1983-1989 E24 BMW 633csi 635csi M6 Show More Show Less