How to fit a rubber bulb primer into a metal fuel line?

[NealB]

I've read a few threads, over the years, where people sing the praises of fitting a rubber bulb primer pump into a diesel fuel line (to make bleeding easier, rather than having to use the awkward lever on the lift pump).

My engine has a metal fuel line.

What would be a safe and easy way to make the connections (between the fuel line and primer bulb), please?

Should I replace the whole of the existing fuel line with a rubber line? The downside is that, to this non-plumber, it'll make connecting the new fuel line a bit tricky at both the tank outlet fitting and at the primary fuel filter.

Or could I just cut out a length from the metal line, and replace it with a short length of rubber line? If so, how do I get a reliably leakproof connection between the the two fuel lines? Could I just push the rubber hose over the metal line, and secure it with jubilee clips?

Thanks for any thoughts.

 

[rogerthebodger]

I would use a short piece of suitable side plastic tube and twin ear clips or worm drive clips

 

[[159032]]

But rather than worm drive I would use fuel line clips. The saddle on worm drive clips, in smaller sizes, prevent even clamping pressure.

Even better are spring clips, provided you get the right size.

 

[rogerthebodger]

I use these

 

[prv]

They look a bit too big to me

Pete

 

[Yellow Ballad]

Cut the metal line and fit two of these compression barbs (in the right size) for the rubber pipe to seal on.

Just pushing the pipe onto the metsl pips is asking for a leak fuel or air imo.

Compression 3/8" OD to 3/8" Hose Barb fitting Transmission Cooler Line Brass: Amazon.co.uk: Car & Motorbike

 

[PaulRainbow]

Or could I just cut out a length from the metal line, and replace it with a short length of rubber line? If so, how do I get a reliably leakproof connection between the the two fuel lines? Could I just push the rubber hose over the metal line, and secure it with jubilee clips?

Yes, you can do it this way, i would use fuel line clips, as shown in the first pic, post #3, make sure they are stainless.

You need to make sure you don't get metal filings in the fuel system. I'd turn the fuel supply off at the tank, disconnect the metal line from the primary filter inlet and cut it off a few inches from the connection, make sure there are no metal filings up the pipe, a good blast with WD40 or anything similar will do the job. Shorten the metal tube, then turn on the fuel supply for a few seconds, catching the fuel that comes out of the cut pipe, which will make sure there are no filing in that cut.

 

[NealB]

Great stuff .... thanks for all the suggestions.

Even I should be able to get something that works from here, but I'm still open to more ideas if anyone has a burning drive to put their own ideas out there.

 

[Sharky34]

I've read a few threads, over the years, where people sing the praises of fitting a rubber bulb primer pump into a diesel fuel line (to make bleeding easier, rather than having to use the awkward lever on the lift pump).

My engine has a metal fuel line.

What would be a safe and easy way to make the connections (between the fuel line and primer bulb), please?

Should I replace the whole of the existing fuel line with a rubber line? The downside is that, to this non-plumber, it'll make connecting the new fuel line a bit tricky at both the tank outlet fitting and at the primary fuel filter.

Or could I just cut out a length from the metal line, and replace it with a short length of rubber line? If so, how do I get a reliably leakproof connection between the the two fuel lines? Could I just push the rubber hose over the metal line, and secure it with jubilee clips?

Thanks for any thoughts.

Put it into a vertical section of the fuel line, making sure you have the arrow pointing in the right direction.
Couple of clips & should be ok.

 

[NealB]

Put it into a vertical section of the fuel line, making sure you have the arrow pointing in the right direction.
Couple of clips & should be ok.

Thanks.

Even I can understand that the bulb needs to be 'in the right direction', but I'm wondering if it's really that bothered whether it's mounted vertically, horizontally or inclined?

 

[Sharky34]

Thanks.

Even I can understand that the bulb needs to be 'in the right direction', but I'm wondering if it's really that bothered whether it's mounted vertically, horizontally or inclined?

Less chance of 'air bubbles' certainly whilst priming if vertical, so full flow at all times.

 

[VicS]

Thanks.

Even I can understand that the bulb needs to be 'in the right direction', but I'm wondering if it's really that bothered whether it's mounted vertically, horizontally or inclined?

Its best mounted vertically, with the flow going upwards. It helps to purge it of air and the little valves inside will work better .

Slightly inclined from dead vertical will be ok but "pointing at the sky" is how it should be

 

[NealB]

Its best mounted vertically, with the flow going upwards. It helps to purge it of air and the little valves inside will work better .

Slightly inclined from dead vertical will be ok but "pointing at the sky" is how it should be

Thanks to you, too, VicS.

What a team!

 

[ghostlymoron]

All the suggestions are to a degree a bodge IMH which is why I prefer to use a filter with a built in bleeding pump. That way you can have an all metal fuel line.

 

[lynallbel]

Have you asked your ins company what their view is on rubber fuel lines?

 

[Refueler]

All the suggestions are to a degree a bodge IMH which is why I prefer to use a filter with a built in bleeding pump. That way you can have an all metal fuel line.

Might be a bodge IYHO .... but many people use it successfully .... its cheap and works. I even added same to my big brute Belarus tractor ... sorted her a treat.

Funny enough - its something that I need to do on my boat - have fitted a number to other peoples boats though !!

 

[pvb]

Have you asked your ins company what their view is on rubber fuel lines?

Have you ever known an insurance company to ask what the fuel lines are made of? If so, I'd avoid them.

 

[lynallbel]

Have you ever known an insurance company to ask what the fuel lines are made of? If so, I'd avoid them.

Not known one to ask, but you can bet your last penny, if you have a fire claim the fuel lines will get a look at.

 

[pvb]

Not known one to ask, but you can bet your last penny, if you have a fire claim the fuel lines will get a look at.

Really? On what basis do you claim that? Loads and loads of boats have rubber fuel lines. Are you suggesting they're all uninsured?

 

[PaulRainbow]

There is no requirement on a boat to have all metal fuel lines, if there was, just about every modern production boat would be in breach of it.

There is also no need to mount fuel primer bulbs in an particular orientation. If there is, someone should contact a few of the major car companies that have fitted them, usually horizontally.

As for it being a bodge, again, someone should contact a few of the major car companies that have fitted them.

it isn't a bodge and should one fail, nothing happens, it just doesn't prime. I've known several of the ones on top of CAV filter heads to fail due to a leaking diaphragm, that mode of failure means air gets into the system, which can be a real pain to pinpoint.