The coolant expansion tank provides an buffer for the coolant to 'overflow' to when the cooling system is running. Replace yours with a new one if it is cracked or if there is corrosion inside.
17-11-1-707-540-M9
Coolant Expansion Tank (cap not included), 528e (1982-88), Each Brand: Genuine BMW [More Info]
$81.00
17-11-1-178-252-M9
Coolant Expansion Tank (cap not included), 533i (1983-84), 535i/is (1985-88), Each Brand: Genuine BMW [More Info]
$65.75
Expansion Tank Hoses
17-12-1-119-294-M101
Water Hose for Coolant Expansion Tank, BMW E28 5 Series, All, Each Brand: Elaplast [More Info]
$3.50
17-12-1-712-736-M203
Breather Hose from Expansion Tank to Breather Pipe, 8 X 13mm, BMW E28 5 Series, All, Each Brand: Rein Automotive [More Info]
$11.13
11-53-1-287-999-M109
Water Hose, Expansion Tank, 528e (1982-88), Each Brand: Mackay [More Info]
