fuel bleeding.

[Novachris]

How do I get fuel back through my system? I took the primary filter off yesterday and before I could get the new one on the system drained. The water trap is also empty. my fuel pipes come out of the top of the fuel tank, so I guess the fuel pump sucks fuel through.
Is there an easy way to suck the fuel back through rather than pump the little handle? engine is Perkins m30.
Thanks.

Edit I did turn the tap off first.

 

[prv]

In theory I think you probably have to pump the little handle on the lift pump, but if it's anything like mine you'll be there all day. Inserting one of those outboard-motor priming bulbs just after the tank will allow you to push fuel into the system and refill the filters in seconds.

Pete

 

[KellysEye]

Unscrew the bleed screw on the engine and put tissue there to catch the diesel. Then use the manual lift pump and keep going until you hear the air coming out stop and diesel appears. Contrary to what was said it doesn't take more than a few minutes.

 

[Lakesailor]

The lever on the lift pump may sometimes be on the lobe of the cam that operates it, and have little effect. Turn the engine 180 degress and the full effective travel of the lever should be restored.

 

[Novachris]

Thanks guys, my last boat was gravity fed, and I forgot the method for this type, I must admit I didn't know which system it was until yesterday... Shame on me.

 

[donm]

In theory I think you probably have to pump the little handle on the lift pump, but if it's anything like mine you'll be there all day. Inserting one of those outboard-motor priming bulbs just after the tank will allow you to push fuel into the system and refill the filters in seconds.

Pete

Seconded for the outboard bulb. My tank is well below the engine and pumping it up with the hand lever on the fuel pump took some time. Introducing the bulb makes it much quicker, but also easier to control the last of the fuel bleeding when the bubbles finish and just neat fuel is being pumped.

 

[prv]

Contrary to what was said it doesn't take more than a few minutes.

Maybe on your engine. Not on mine. And yes, I'm well aware of the cam position issue.

Pete

 

[Novachris]

Hi guys, all done... I used the lever on the lift pump, but had an out boat bulb at the ready just in case, but after about five minutes the water trap was full, and it is a short run to the primary, so persevered with the lever...took about ten minutes in all.
Thanks for the input guy's.

 

[Grumpybear]

I have a replacement Delphi primary filter/separator with a rubber dome type priming pump on top. About two or three presses usually suffice to bleed the whole system. The whole thing cost less than half the cost of replacing the corroded innards of the reusable element filter put there by the builder. Well worth the outlay.

 

[srp]

I've got one of those priming pumps - a direct fit onto the primary filter. Works brilliantly. I have never had any success trying to prime the whole length of the pipe from the tank pick up by just using the engine lift pump.
A good alternative is to use a dinghy pump on the fuel filler pipe to pressurise the tank and force the fuel through - i've used this a couple of times. Also a length of hose and a good pair of lungs will do the same job if you don't have a dinghy pump, sometimes you can connect to the breather pipe rather then the much bigger fill pipe. Always a help to have someone else with you, unless the tank is very close to the engine.

 

[widgeon]

Following advice from a marine engineer friend, I tried a new method last time I changed the filter. I removed the bleed screw from the top of the engine filter, inserted the tube of my Pela oil-change pump, with a bit of insulating tape around it to give a reasonable seal inside the screw thread. A few pumps on the Pela rapidly pulled fuel through all the way from the tank. I then removed the pipe, reinserted the screw and started the engine. My Volvo MD 2020 is happy to deal with the last bit of air in the pipe work, but I could have done a little bit of pumping of the engine fuel pump level if necessary.
Swift and painless compared with lying on the cockpit sole with arm trying simultaneously to bend in 3 places while pumping the little lever for what seems like hours!

 

[michael_w]

Have a self-bleeding engine with an electric lift pump (smug git mode off!)

 

[theoldsalt]

Have a self-bleeding engine with an electric lift pump (smug git mode off!)

I agree.

When my mechanical lift pump failed I replaced it with an electric one. Engine starts quicker and bleeding is so much easier.

 

[Novachris]

I agree.

When my mechanical lift pump failed I replaced it with an electric one. Engine starts quicker and bleeding is so much easier.

That sounds interesting... Have you got the info to hand? in case I ever need to replace mine.

 

[neil1967]

I also have an electric fuel pump, fitted directly after the primary filter. It has enough suck to lift the fuel from my built-in bilge fuel tank and fill all the filters, which means I just have to open the various joints and bleed screws to get the air out while it is running. Much easier than using the mechanical fuel pump primer, and avoids repeated turning over of the engine on the starter. It is always in series, so should the mechanical pump fail, I could just use the electric one.

Neil

 

[prv]

It is always in series, so should the mechanical pump fail, I could just use the electric one.

You might also find it keeps you going for a few more minutes in the event of a blocked filter, which might just get you through the narrow harbour entrance to somewhere you can drift or anchor to change it.

Pete

 

[pmagowan]

None of you know the joy of a mouth full of diesel!

 

[theoldsalt]

That sounds interesting... Have you got the info to hand? in case I ever need to replace mine.

The engine is a Thornycroft T80 and the pump fitted is a Facet.

http://www.fuelpumpsonline.co.uk/facet-fuel-pumps-8-c.asp

View attachment 43567

The Facet pump is on the right of the photo and the blanking plate where the old mechanical pump was fitted is on the left.

The electric pump is wired to the ignition switch and runs as soon as the ignition is on. Therefore the injectior pump is primed even before the engine is started giving very quick starting. It also means that bleeding the system does not require turning over the engine on the starter.

 

[Novachris]

Thanks, will look into that.

 

[macnorton]

I connect the Pella (oil extractor) on the return line to suck the air out which pulls the fuel through without getting a thumb blister! and you can have a beer while you wait..