how does the fuel pump on my 18hp briggs&stratton work?
this is a sears riding lawn mower/tractor and the pump is mounted on the heat shield
I have an 18hp Briggs & Stratton Vanguard. Not sure if it is the same type fuel pump as on yours but they probably work about the same. My fuel pump has two check valves and two diaphragms. There are three hoses connected to the fuel pump (gas inlet, gas discharge, and a pressure hose connected to the engine). When the engine turns over, the pressure hose cycles pressure/vacuum to the fuel pump which is applied to the diaphragms creating the pumping action. The inlet check valve allows gas in but not out and the discharge check valve allows gas out but not in.
I assume you are asking this because your pump is not working properly. Some common things to check. Make sure the check valve are seating properly. Check for holes in the diaphragms. (they are the little circular pieces of plastic on each side). Check for holes in the inlet line. (this will cause the pump to suck in air instead of gas and give the appearance of the fuel pump not working)
