How to Install a Holley Umbrella Seal

The umbrella seal in your Holley carburetor is part of the accelerator pump assembly, which enriches the fuel mixture for better acceleration. A damaged umbrella seal will disturb fuel metering, causing performance problems. The umbrella seal, however, is relatively accessible. Make sure to keep all screws, pins and small wire locks in a safe place after removing your carburetor. Cover the intake opening to prevent dust particles, screws and small pieces from falling inside.

Instructions

Removing the Umbrella Seal

1

Set your carburetor on the clean surface of a workbench or workspace.

2

Unscrew the four bolts securing the fuel bowl to the carburetor. The bowl is the large cap attached to the side of the carburetor. Use a thin wall/deep socket and ratchet. Keep the screws with the bowl in their original position when removing it.

3

Unscrew the accelerator pump cover from the fuel bowl. The accelerator pump cover is the small square plate with the lever in the middle. It is attached to the fuel bowl with four Phillips screws. Use a Phillips screwdriver to remove the screws.

4

Carefully lift the accelerator pump cover from the fuel bowl and remove the diaphragm and spring from under the cover. With these components removed, you will see the umbrella seal at the bottom of the accelerator pump compartment. The seal is the flat orange rubber disc.

5

Remove the umbrella seal by cutting the holding nipple from the bottom of the umbrella seal. If you turn the fuel bowl upside down, you will see the other side of the umbrella seal, a small nipple that goes through a center hole inside the accelerator pump compartment. Cut off the nipple with a pair of diagonal cutting pliers, then remove the seal.

Installing the Umbrella Seal

6

Carefully push the nipple on the new umbrella through the hole at the bottom of the accelerator pump with your thumb.

7

Replace the spring and diaphragm into the accelerator pump and fasten the cover with the Phillips screwdriver.

8

Replace the fuel bowl and tighten the four bolts using the thin wall/deep socket and ratchet.

9

Replace the other umbrella seal, if your Holley carburetor is equipped with another fuel bowl. Follow Step 2 from the "Removing the Umbrella Seal" section through Step 3 of this section.