The Ford small block 302 has been in trucks and cars for many years. The engine, though itself reliable, went through a period where the factory oil pump was notoriously unreliable. The pump check valve would stick open, and oil pressure would be too high. Often this would result in blown seals, or even the oil filter housing blowing off. If this was not the case, the oil pump would often still fail, the pressure would drop too low, and if not repaired in time this could cause severe engine damage.
Find the oil pressure sending unit. Most for cars and trucks with the 302 engine have simply an oil light, or a gauge that is simply off or on if pressure is in acceptable ranges. The sending unit for this light or gauge is next to the oil filter.
Disconnect the electrical connector from the sending unit, and using the oil sending unit socket, remove it. Usually the electrical connection is a single wire.
Screw in the adapter for the oil pressure tester. Attach the pressure tester hose to the adapter. If the location is too tight to install the gauge, use a 45 degree adapter. These adapters are often in the oil pressure tester kit, or available at a local auto parts store.
Run the engine until it is warm. Oil pressure reading should be between 35 and 60 psi. If it is outside that range, the oil pump is faulty and must be replaced.
