Fuel Pump Diaphragm Tool

By Ken Daugherty

I am illustrating a tool to set the A/B fuel pump diaphragm in the neutral position and tool to set the diaphragm and to remove the little clip from the C/912 fuel pump.

'A-B spacer block' shows the small wooden block that depresses the pump lever. The block is approx. 1/4" x 3/4" x 1 1/4".

'A-B pump tool' shows the block, 2, 30mm bolts and huts and a standard fuel pump block off plate.

'A-B' tool' shows the pump diaphragm in the neutral position, ready for final assy of the cover. (the diaphragm is this picture is a used one for illustration purposes only)

'C-912 pump tool' the component parts. A piece of sheet metal, ~16 ga., 1" x 5 1/2", A piece of conduit, ~7/8" x 1 3/8" long and 4 bolts, 2, 45mm and 2, 75mm' and 2 hex nuts.

'C-912 clip tool' This holds the diaphragm in placed so the clip spring can be compressed and the clip removed.

'C-912 diaphragm set tool' To set the diaphragm in the neutral position so the top cover can be properly fitted.

'Tool held in vice' This is why there is a bend in the metal.

One final picture to illustrate what happens when the diaphragm in not properly centered. Note the wrinkle in the diaphragm, causing premature failure.

Technical advice given on these pages is provided free and without warranty. The user of information presented on these pages assumes all responsibility and liability in its use. We're not lawyers, we're car folk, just sharing our experience. Be careful, use your head, have fun.

Questions or comments, please email to Barry Lee Brisco, Website Technical Editor,