Fuel Line/Separator/Pump Questions

[bds85466]

Re: Fuel Line/Separator/Pump Questions

USCG rules say that you need 1 piece steel tubing from the fuel pump to the carb. With nothing, no filters, in between. You'd to best to also keep that steel line off of the exhaust manifolds. To make it, you buy off the shelf straight tubing (brake line tubing) from NAPA. Then you need a tubing cutting, a flareing tool, and tubing bender plumb in the line to size.

Yeah the pic is deceiving, but I don't believe anything is resting on the manifold.

Anyone know of a tutorial for doing something like this? I see bending/flaring sets aren't too spendy -- how do you get the brass fittings on? Pardon my inexperience, but is this part of the "flaring" process?

 

[Rocky_Road]

Re: Fuel Line/Separator/Pump Questions

Yeah the pic is deceiving, but I don't believe anything is resting on the manifold.

Anyone know of a tutorial for doing something like this? I see bending/flaring sets aren't too spendy -- how do you get the brass fittings on? Pardon my inexperience, but is this part of the "flaring" process?

Yep.

You slide the fitting onto the unflared tube...and then you make the flare!

 

[bds85466]

Re: Fuel Line/Separator/Pump Questions

Thanks all. It's been a long, but educating day here at work

I may try out a new strap wrench 2nite. speak with everyone tomorrow.

 

[Maclin]

Re: Fuel Line/Separator/Pump Questions

Strap wrenches have been very, very good to me.

 

[Chris1956]

Re: Fuel Line/Separator/Pump Questions

I do not recommend driving a screwdriver thru the separator. I have done that with an oil filter and it it failed miserably. The filter face was still just as tight, oil was all over the place and now there was not too much left of the filter to grab. I ended up using a pipe wrench on the filter face. Not too much fun and a mess.

 

[bds85466]

Re: Fuel Line/Separator/Pump Questions

didn't get a chance to try the new strap wrench.

was looking at fuel lines. I included a pic from the iboats store. Would one of these work to replace the tube I have with the inline filter? Would you assume these are ridgid? Bendable? Flexible?

 

[bds85466]

Re: Fuel Line/Separator/Pump Questions

bump...

anyone know about these "universal" fuel lines?

 

[JustJason]

Re: Fuel Line/Separator/Pump Questions

Nope... I've always just made them up.

 

[PiratePast40]

Re: Fuel Line/Separator/Pump Questions

As far as the pre-flared fuel lines - I'd go with that any day over trying to do a double flare myself. Some are more skilled but I've allways felt the factory tools were better than what I could do by hand.

 

[bds85466]

Re: Fuel Line/Separator/Pump Questions

Thank you for the response, do you know where to get a good selection of pre flared/nutted lines? I'd be comfortable bending em up, as I'd be most worried about my flare fittings leaking...

 

[JustJason]

Re: Fuel Line/Separator/Pump Questions

You can get the lines at napa. The tools at sears.

 

[bds85466]

Re: Fuel Line/Separator/Pump Questions

Update:

I brought home a "big bertha" of a strap wrench and glided through the removal of that filter like butta. Having the right tool is obviously the name of the game.

This gave far better access to view the fuel pump. I've included pictures, including where gasoline is collecting.

The gasoline appears to be leaking from the fitting area between the pump and black fuel line. I can't really tell if it's from the fuel pump side or the line side, but it appears to be at this junction. After drying the entire underbody of the fuel pump, this area (with the red arrow) was the first to get wet, and the under body of the fuel pump remained dry.

Here's my question, does this information mean that the fuel pump is still faulty or might it be a bad junction? I mean, it doesn't make sense to replace the fuel pump when it's simply a bad seal to the line.

I think I'm ready to order a fuel pump to replace my current one, but I want some advice on making sure that it's the problem. Any thoughts?

 

[JustJason]

Re: Fuel Line/Separator/Pump Questions

Tough to say because its not in front of me what is actually leaking. But in the first pic it looks like there is teflon tape on the threads of the fitting. Pull the fittings in the pump (the seats) and remove any and all tape. Use teflon pipe dope on the threads and reinstall them. For the lines that go into the seats, nothing is needed on those threads. Make sure there is no tape on them then tighten them down dry.

 

[bds85466]

Re: Fuel Line/Separator/Pump Questions

Thanks Jason, and thanks for bearing with me as these fittings are completely new to me. Having said that, I have some questions:

I take it these fittings are not 1 use only, then? -- unline like a swage fitting?

If I understand you right {for the black line at least}, this is a '3' piece system. The fuel pump, a fitting (seat), and the fuel line/nut? The seat (male on both ends?) screws into the fuel pump (female), and the line (female) screws into the other end of the seat?

Moving on --

The seat threads should be teflon doped (but not taped) and screwed into the pump. The line should be celan and dry when you tighten it to the seat.

Making the above assumptions, what tools would I need to perform this? Would this be the correct order for tightening (tighten seat into pump, then line into seat?) and loosening? I'm assuming you'd need two wrenches?

 

[JustJason]

Re: Fuel Line/Separator/Pump Questions

The hole in the fuel pump with threads is just that. A threaded hole in the pump.
You need something to adapt the specific size fuel line to that hole. That is where the seats come in. They are the adaptor between the pump and the fuel line. For example, if you were using a smaller fuel line, then you would need different appropriatly sized seats. They also are 1/2 of the seal, the other 1/2 of the seal is the flare in the steel tubing. To form the seal all you are doing is tightening brass on steel. Its low pressure, and will keep things from leaking.

For tools you ideally need a flare nut wrench set. And a standard wrench set. Don't ask me the size... I have no idea.
http://www.sears.com/shc/s/p_10153_12605_00944096000P?keyword=flare+nut+wrench+set

 

[bds85466]

Re: Fuel Line/Separator/Pump Questions

Thanks Jason. You've been a big help.

 

[bds85466]

Re: Fuel Line/Separator/Pump Questions

update:

last night in the rain -- it's been raining here in MN for about 5-6 days straight now -- i pulled the inlet line to the fuel pump. I removed the line/nut and then removed the fitting. I cleaned up the fitting, added some teflon pipe dope and replaced. I dried off the hose nut nicely and reattached everything. I then replaced my fuel water filter and turned the boat on.

Let it run in low rpm for a good 5 minutes, saw some surging/pulsing, but it didn't die or anything, just a little rough (could be something else). Turned it off and found that the pump was still leaking from the same area.

Looks like it is the pump? I put a new one on order.

Comments?

 

[bds85466]

Re: Fuel Line/Separator/Pump Questions

here's some more info on the fitting (pics 1 & 2) which goes between the fuel line and the pump. Looks to be in decent shape. The threads are definitely pipe threads, don't appear tapered, but I'm no plumber.

A buddy of mine recomended I retry my little exercise using teflon tape on both ends of the fitting instead of pipe joint compound.

Today at work I screwed the pump fitting into another which I had laying around. I plugged the one end with my finger and filled it with water. The fitting leaked at the seams. (pic3) I then dried off and repeated with teflon tape -- nothing leaked in this configuration (pic4). I'm tempted to try this one more time with the teflon tape to see if it stops the leak.

Comments?

as a ps...The pump replacement is sierra 18-7283