Why not to put auxillary fuel pump!

[Ron Dague]

There was some discussion about using a small pump in the fuel line to make bleeding the lines easier. Some writers used manual bulbs. Here's my experience:I had a small, diesel compatible, electric fuel pump, in the fuel line, before the Racor filter. It does make bleeding the line easier. But, while sailing yesterday, it began to leak from one of the seals. By the time I found the problem, removed the pump, and re-connected the line, 1/2 gallon of diesel fuel was in my enging bilge. Fortunately, I keep the plug in, so it didn't drain into the main bilge. So, a fun afternoon of pumping the bilge fuel into a bottle, wiping up the rest, and then removing the pump from the line.Here's the lesson that I learned (and I'm not trying to tell anyone else what to do, just my decision): Having removed that pump, I won't replace it. Every additional mechanical device put in the fuel line is one more part to break or leak, when you least expect or need it. And although careful visual inspection is valuble, it isn't foolproof. By using just the lift pump on the engine, if I have a problem, it will most likely be at the dock when changing filters, not at sea. If it takes me a little longer to put in new fuel filters and bleed the lines, I'm willing to trade that time, for a less complex and less likely to break, fuel system, when under way.Just my humble opinion.

 

[Stephen Ostrander]

good advice

You certainly make a strong argument here. OTOH, a manual squeeze bulb is a pretty simple device, with only the possibilty of it leaking at the hose connections. I have had one installed for 2 seasons, no leaks, and in my experience, about 2 squeezes equals about 50 pumps of the manual lift pump. But I may find myself in your situation someday, and then re-evaluate my decision.

 

[Bryan C.]

Ditto Stephen

And don't be so sure you are not going to need to bleed out on the water. So far 3 x in the last year and a half.

 

[Walt Golembewski]

Elec fuel pumps

One nice thing about an electric fuel pump is that is provides redundancy. Most low-wing single engine aircraft have a mechanical and an electric fuel pump, with the electric operated on demand by a toggle switch. Being a pilot as well as a sailor, that's the approach I used when I installed an electric pump on my 37 cutter. It's off most of the time, but I can put it on when I need to -- to purge the lines, or, in one case, to keep the engine going when a filter picked up some sludge. My toggle is mounted on the engine instrument panel. Has worked fine for the past 5 years.

 

[Sam Lust]

Yes to electric pump

I've got to go along with electric pumps. I've got a simple little pump in my system that was marketed as Purolator that I picked up at Pep Boys. It's a sealed unit and I can't for the life of me see where it would be able to leak from. In addition to easing bleeding chores. At least 3 times in 3 seasons while on the water. In addition to the normal filter changes. I've set it up so I can run the fuel through the filter and straight back to the tank. Best way I can think of to keep existing fuel clean.I have a switch (single pole-double throw) also, but below deck where I can get to it while bleeding. One side runs the pump from the engine switch, the other runs it from the electrical panel, and the middle position turns it off. Good quality components and I expect no problems.

 

[Gordon Torresen]

Electric bleeding pump ???

There is a lot of good information in the previous posts. True, an electric fuel pump in the circuit eases the bleeding procedure. It will probably reduce a thirty minute job down to 25. Redundancy is a nice option but many boats have this already because of the elevation of the tank. Also, the high pressure pump will suck along the fuel as long as there is no air. Having to bleed three times when not changing filters should be reason to look for another problem. That air should not be getting in.  Not having the pump because a pump failed is covered in the message to use quality components. On the other hand, the statement that every additional joint in the fuel line is a potential leak is very valid. The simplicity of the squeeze bulb is good. Also, the squeeze bulb precludes the need for electrical wiring that could also cause problems. The best way to reduce the time spent in changing filters is to install a vacuum gauge in the line before the lift pump. If the gauge stays near zero, don't change the filters. If you keep your fuel clean, you may never change another filter. The only thing that makes a filter change mandatory is if the filter is dirty. Racor makes a vacuum gauge kit that is easy to install and can be mounted where ever you choose to look at it. Granted, it puts joints in the fuel line, but it is quality stuff. If the gauge starts to climb, its time for a filter change and time to find out where the contaminant originated. A lot of good pros and cons.