Bleed the Engine Fuel Lines

Parts / Tools

• Various scanners to crack the bleed screws.
• Rags for cleanup.

Method

• If any work has been done on the fuel lines, it s possible that air would have entered the lines. This needs to be removed; at best it will require excessive cranking to start the engine potentially draining or damaging the starter batteries, at worse the engine will not start at all.
• The principle is to use the bulb pump to push fuel from the tank to the high-pressure pump past 3 bleed points. There is a bleed point on each fuel filter, and also one on the engine itself.



Bulb pump.

• The method is to pump the bulb pump while holding each bleed screw slightly open in turn. Continue pumping while air or bubbles leak from the screw. As soon as liquid-only comes out if the screw, tighten it while maintaining pressure via the pump.
• External (CAV) filter. The bleed screw is the larger of the two on top of the filter.



CAV filter bleed screw.

• On-engine filter. The bleed screw is on top of the filter.



On-engine filter bleed screw.

• Engine high-pressure pump. The bleed screw secures a banjo fitting to the pump.



Engine high-pressure pump bleed fitting.

• If the engine does not start, or starts and then stops, repeat the purge - there are probably remaining pockets of air.