Heater Pipe O-Ring - E46 323i/325i/328i/330i

Coolant hoses are sealed with a rubber o-ring inside the connector. Any time the hose is removed or disconnected the o-ring should be replaced. The o-ring can shrink with heat and time or become damaged. It's common to have leaks when re-using the hose and o-ring.

Instead of replacing the entire hose we offer the correct size replacement o-ring. This o-ring is an alternative to BMW part #11531435808 but is slightly larger for a better seal. This o-ring is used for the heater pipes on the side of the engine block and the return hose to the expansion tank.

These are made of Buna-N (Nitrile) rubber and are compatible with coolant, water, grease, hydraulic oil, and engine oil (not brake fluid). They are rated for temperatures of -40°F to 250°F.