Radiator Cap 1.4 Bar - E30 325e/325i & E34 525i M20 - 17111742232

Direct replacement radiator expansion tank cap for M20 powered BMWs, including the E30 325, 325e, 325es, 325i, 325is, and 325ic (325i convertible) as well as the early E34 525i with M20. This cap is rated at 1.4 bar (20.3 psi / lbs) of relief pressure. 

The radiator cap is designed to be the first point of preventative failure on the M20 6 cylinder cooling system. If the system gets too hot and/or over pressurized, this cap is design to blow off at 1.4 bar of pressure, or about 20.3 PSI. This is to prevent a more catastrophic cooling system or engine failure. Because of this built-in failsafe, the radiator cap is a maintenance item on its own. Fortunately it's super easy to change – but NEVER remove a radiator cap when the engine is still warm. ALWAYS allow the engine to fully cool (several hours) or change at a complete cold start to avoid the risk of burns or physical harm. 

This cooling system cap is an aftermarket unit, made to work, fit, and relieve pressure just like the original BMW unit. This is a simple design, with a simple price tag, which is great if you're just in need of an inexpensive new radiator / expansion tank cap. 

Replaces BMW part numbers 17111742232 (17 11 1 742 232) and 17137639023 (17 13 7 639 023).