Fuelab Diaphragm & O-Ring Kit for 535xx/545xx Series Regulators - All Models

This diaphragm and O-ring kit from Fuelab is specifically made for their 535xx and 545xx series fuel pressure regulators. The diaphragm is a critical component that separates the fuel side from the vacuum or boost reference side of the regulator. Over time, these diaphragms can wear out or become damaged, leading to inconsistent fuel pressure or leaks. Replacing it with a fresh, well-made diaphragm and new O-rings ensures your regulator continues to function as intended, maintaining stable fuel pressure under all conditions.

This kit includes all the necessary O-rings to properly seal the regulator body after the diaphragm is replaced. Using the correct, factory-specified components like these ensures a proper seal and prevents fuel leaks or vacuum/boost leaks that could affect engine performance. It’s a straightforward way to service your regulator and get it back to performing reliably.