MX-5 / Miata NC Fuel Tank Top Hat

Disconnect the fuel-pump and level-sender wiring from the underside of the OEM top hat. Release the connectors carefully and pull on the connector bodies rather than the wires.

Use the small flat-bladed screwdriver to release the level-sender retaining tab, then slide the sender assembly out of the pump basket. Put it somewhere safe where the float arm cannot be bent.

Using the pick tool, remove the E-clips from both steel guide rods beneath the OEM top hat. Keep both clips safe for reassembly.

At the lower end of the basket, remove the E-clip from the spring-loaded guide rod. Withdraw both steel rods from the basket, keeping note of which rod is longer and the position of the spring.

Release the three retaining tabs that hold the fuel-pump housing into the basket. Lift each tab only as far as needed and begin easing the housing upwards.

Remove the venturi retaining clip at the base of the basket, unclip the black hose from the side of the basket, then pull the fuel-pump housing fully out of the basket.

Using a Stanley knife or sharp utility blade, carefully cut the black corrugated fuel hose where it joins the pump housing. This separates the OEM plastic top hat and hose from the pump housing. The basket should now be stripped and ready for the new top-hat assembly.

Remove the four 3mm Allen bolts from the aluminium top hat and lift off the top cover. Put the cover and four bolts to one side for now.

The three rings are laser-marked Ring 1 – Top, Ring 2 – Mid and Ring 3 – Bot. Each ring has an alignment notch. Keep the engraved faces upwards and use the notches to maintain the same orientation through the rest of the assembly. Set Rings 1 and 2 aside for the moment; Ring 3 is fitted first.

Reinstall the two upper E-clips into the grooves in the steel rods before fitting the rods through Ring 3. Make sure each clip is fully seated before continuing.

With the basket in front of you, orient it so the flat side is to your left. Hold Ring 3 with the larger rod holes at approximately 12 and 6 o’clock and the alignment notch at approximately 5 o’clock. With the upper E-clips already installed, feed the steel rods through Ring 3 with the longest rod in the 12 o’clock position.

Place Ring 2 (Mid) and then Ring 1 (Top) onto Ring 3. Keep the alignment notches together and make sure the rod holes remain correctly aligned with the text face-up.

Lower the top plate onto the ring stack. Apply a small amount of thread-locking compound to the four bolts and reinstall them with the 3 mm Allen key. Tighten the bolts evenly until hand-snug only.

Install the Mazda sealing gasket around the outside of the top-hat assembly, aligning the moulded notches and cut-outs with the corresponding features in the plate. Make sure the gasket is fully seated and is not twisted.

Turn the basket through 180 degrees so the spring is facing you. Lower the rods back into the basket with the longest rod closest to you. Seat both rods fully, compress the assembly as required and reinstall the lower E-clip.