Holley 135-11 Secondary Diaphragm Replacement Kit for Vacuum Secondary Carburetors

The Holley 135-11 Secondary Diaphragm Kit is a factory-spec replacement diaphragm assembly designed for Holley vacuum secondary carburetors. The secondary diaphragm controls the opening rate of the secondary throttle blades by responding to engine vacuum, ensuring smooth, progressive throttle response under acceleration. Over time, diaphragms can crack, harden, or develop pinholes, causing hesitation, stumbling, or a failure of the secondary barrels to open properly — this kit restores proper operation.

Key Features:

• Direct OEM-style replacement for Holley vacuum secondary carburetor applications
• Restores proper secondary throttle blade actuation and progression
• Manufactured to Holley's original material and dimensional specifications
• Corrects hesitation, stumble, or no-open conditions caused by a failed diaphragm
• Easy, straightforward installation with basic hand tools
• Compatible with a wide range of Holley 2300, 4150, and 4160 series vacuum secondary carburetors

This kit is an essential part of any carburetor rebuild or tune-up on vehicles equipped with Holley vacuum secondary carburetors. Replacing a worn or damaged secondary diaphragm is one of the most common and effective steps in restoring crisp throttle response and proper fuel delivery on classic and performance vehicles.