Advice installing a bulb in fuel line

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Don

Planning to install a bulb on the fuel line of my '84 H31. Quick question: if I fill the bulb with fuel when I install it, will I still need to bleed the system following the installation? I had my first experience (kinda bad one) getting air in my fuel 2 weeks ago. I was motorsailing, heeled over, with low fuel in the tank. The fuel pickup must have sucked air 'cuz we did too when the engine died. What's worse is I had no one to blame but myself. Suffice it to say that I learned about bleeding the hard way. Assuming I do need to bleed the system after installing the bulb, I would loosen the bleed screw on the fuel filter and pump the bulp until I see fuel (and no air) at the screw. Right? Will I have to go further, i.e. to the injectors? Any advice would be appreciated.
 
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Allan Hadad

Bleed Point

When I put the fuel bulb in my system, I bled it at the filter (on the engine), then again at the high pressure pump. It wasn't necessary to do each injector. One thing I notice is if I pump the bulb with nothing open for bleeding, it pressurizes up real hard and fuel is forced out of my Racor between the o-rings. Probably not a good idea. Otherwise, it works fine and makes it easier to get back underway after sucking air into the system or losing prime after filter changes, draining water, etc. Allan
 
Dec 2, 1999
15,184
Hunter Vision-36 Rio Vista, CA.
Thumb pump?

Don: I suppose that the reason that you would want to add a bulb to the fuel hose is to expedite the process of pumping fuel from the tank to the engine? My question is this then becomes a TWO person job, doesn't it? Someone must get in the pit and someone at the engine on the bleed screws. Is it not easier to just open the lower bleed screw and use the finger pump. I suppose that if you are changing the filter this makes getting the fuel in the filter bowl much quicker. Someone had a post here that suggested you just blow into the vent hose until the fuel begins to flow. Wouldn't that work just as well?
 
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Don

Steve - that's how I pump out my holding tank.

I put a friend on the HT vent and get them to blow! Re the bulb on the fuel line, when I got stuck 2 weeks ago we could never make any progress with the thumb pump. The "expert" help I had said those pumps were fairly inefficient if a significant amount of air had been consumed by the engine. Hence the bulb on the fuel line. It seems that everyone here is a big fan of 'em. I can't believe you have not installed some automatic solar powered electic fuel pump with a foot switch to bleed your system. Anyway, I'm thinking the bulb could go just aft of the engine and would be accessible from the cabin, behind the dipstick. Or am I imagining things?
 
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Bryan C.

Bulbs

I also am a big fan of fuel bulb pumps, got the tip right here on the HOW. I put the bulb in the fuel line after the primary filter just before the lift pump on the engine. It really takes the place of the lift pump. So the answer to your question Steve, is no, it does not take two people since the bulb is locate right there by the engine.
 
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Bryan C.

More bulbs

Don, the answer to your question is yes you still probably need to bleed even if you had filled the bulb up with fuel (not quite sure how or why you'd do that). Any air in the system can shut the diesel down. But its no big deal, as the other posts mentioned just the secondary filter screw and at the second point (high pressure?) are all I've ever needed to do -- i.e. never had to do the injectors. I changed both primary and secondary filters last week, installed the new filters dry, and a few squeezes on the bulb and pssssst --- diesel was squirting all over my shorts.
 
Dec 2, 1999
15,184
Hunter Vision-36 Rio Vista, CA.
Don & Brian:

Brian: That's really a good idea. Thought that everyone was putting them in the PIT. Don: That's a bad idea (running out of fuel). Honestly in the 15 years that we have own the boat, I have NEVER (knock on fiberglass) run out of fuel. Came close once but didn't make it. I guess I will consider the solar powered electric version some day. Until then I will try to keep the tank topped off and I am going to get an Acugage system in the few months. Just analyzing the mounting of the electronic display. Did not want to cut a big hole in the bulkhead so trying to come up with a mounting box so I only need the hole for the wires.
 
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terry dornan

Ya know ?

Certain materials are not exactly suitable for use with diesel fuels. Most of the bulbs I have seen have been designed for gas, I think you are taking a pretty good risk in material deterioration, and possible leaks. If you consider the fact that you filter your fuel to 10 micron to avoid blockage of injection pump ports and fuel injectors, a little degradation of the bulb could be very expensive. The bulb pumps I have seen, rated for diesel fuel, are specified for fuel transfer as in filling heaters and lamps. Terry
 
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Bryan C.

Good point Terry

There is that possibility. I don't know enough about chemistry as to whether diesel might deteriorate a rubber that can handle gasoline. I've had mine for 2 years and haven't noticed any deterioration, but I'm going to give her a close look now. In any event, there is still the 2 micron secondary (engine mounted) filter between the bulb pump and the engine which ought to catch anything that might come lose from the bulb pump. But still, probably makes sense to get a bulb designed for diesel fuel (if you can find it).
 
Sep 24, 1999
1,511
Hunter H46LE Sausalito
terry's point

In a previous boat I had a bulb collapse after maybe 5 years of use. Of course, this happened while becalmed offshore, at which point it occurred to me that I should have been carrying a spare. Finally pulled the bulb out of the line, spliced everything back together, got seasick for the first time in my life and then used the lift pump to get started again. I consequently don't use a bulb in the new boat, but could be talked out of that if I could find one designed for diesel fuel. And a spare.
 
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Robert Gillan

Bleedin' Pumps

I change the primary fuel filter annually and the secondary semi-annually and use the engine mounted bleed pump to bleed the system. Not a problem. And yes, diesel will cause those bulbs to deteriorate over time unless the manufacturer rates them for that fuel as well as for gasoline. This discussion was here about a year ago: same stuff.
 
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Ron Williams

they make both

If you check in the catalogs you will find that they make both gasoline and deisel bulbs.
 
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george kornreich

I removed mine.

The dealer I bought my boat from installed a bulb (gasoline type) BEFORE the primary filter (sounds like most of you install it AFTER). I made a thousand calls to find out if they were safe, subject to being eaten by diesel, or even a fire hazard. I couldn't find anything negative about this setup, but it still made me uncomfortable. Well, last winter I upgraded my Racor primary to a larger one and discovered that they make models that come with manual pumps, so that's what I got, and removed the bulb. The manual pump doesn't move as much fuel with each stroke as the bulb would, but far more than the thumb-pump on the lift pump does. Now I'm happy! Next project is to put a second primary in parallel with the present one, and that'll have a pump on it too. Also plan to add a pressure guage which Racor makes to tell when the filter is beginning to clog.
 
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