Difficulty bleeding fuel line SO34.3

[lcochrane]

I am having a lot of difficulty bleeding the air out of the fuel line when I replace the 2 fuel filters on my SO 34.2
I follow the manual's instructions but the lift pump seems to have little or no effect.
I have tried turning the engine over 1/4 turn and repumping many times but still no help.

Any advice.
Thanks in advance

 

[sailorman]

how about a dinghy pump down the filler pipe , suitably sealed around with rag to pressurise the tank with bleed screws bled from tank > engine.
failing that a outboard type fuel line bulb inline before the filters

 

[TradewindSailor]

Here are a few suggestions:
Buy a 12v inline diesel pump and place it between the tank and first filter. This will provide the pressure head for bleeding and will identify any leaks up stream. Once the engine is bled it can be switches off as the fuel will simply be pumped through it as if it is a one-way valve ..... no more reason to use the manual pump
While the fuel line is parted blow down the line to the tank to get rid of any muck in the line. Unfortunately you probably don't have an inspection plate in the fuel tank or a sampler pipe to get any muck / water out of your tank.
I have in the passed inserted a clear hose in order to detect air being drawn in at the filters ..... but it is better to see if there are any fuel leaks out .... hence the pump before the filters.

 

[lcochrane]

Thanks for the advice.
Does this mean that the existing system is inefficient or am I doing it wrong?

 

[TradewindSailor]

Your asking a manual lift pump to suck air. If there is air in the first filter, you are asking for a efficient pump and rapid movements to take up the expansion, contraction of the air.

 

[nigelmercier]

Last time I changed the filters I also drained the inlet pipe fully as I was installing a new unit. I filled the secondary filter with fuel and tried the starter. Bingo! First time, no priming.

 

[Laundryman]

Introduce a squeezy outboard type bulb into the fuel line and the problem is no more. Bleeds the system in seconds. Thanks. Alan