Case 445 manual plunger/primer

Hey,
wondering if any actually found it or if it's just a myth.... Doing some service work on my machine. The fuel filter is spun on but could not find the above. Assuming case 430's, 40's etc. would have the same system. Operator manual says to back of the air screw and use the plunger to fill the filter but doesn't show it on the drawing. Thx.