TR2/3/3A TR3A fuel line

[bigjones]

Hi folks,

Could someone please confirm that the rubber fuel line that leads up to the glass bowl of the pump is 1/4" ID. The rubber is showing a slight crack and I need to replace it.

I was going to cut the line at the glass bowl, temporarily install a metal shut-off valve (any suggestions?), lower the line down to the ground and then drain out the gas into a container. Any better ideas to reduce spillage?

Then I'll install the new line (with the valve).

I've also heard, over in the Spridget forum, that gas line for fuel injection, though a bit more expensive, is preferable. Any thoughts? The reason I ask is that a while ago I came across little black specs in the carbs that I believe to be from the rubber fuel line.

Also, the PO just had a rubber line from the pump to the carbs - I'm thinking I should get the proper steel line for safety, don't you think?

Cheers!

 

[TR3driver]

Mine is 5/16" id, which I believe is correct for the later cars as well.

Best way to reduce spillage is to run the tank nearly empty first. I might even be tempted to use my "backup" electric fuel pump to transfer the fuel to another car.

For just a temporary shutoff as you are proposing, you can just stick your finger over the end of the cut line, or stuff something into the line.

IMO, buying "fuel injection" line is a waste of money. It's made from the exact same 'rubber' as low pressure line, just has stronger internal reinforcement to handle the extra pressure. The issue is that older low pressure fuel line was made from a different material that will not stand up to the ethanol (and other chemicals) found in modern gasoline. But anything made in the last 20 years or so should be just fine.

And either way, it should be replaced every few decades. The stuff just doesn't last forever.

 

[jdubois]

I know Gates recommends using SAE 30R9, which they call 'fuel injection hose', not SAE 30R7 which they call 'fuel and oil hose'.

https://www.gates.com/common/downloads/files/Gates/brochure/TechTipsForm.pdf

 

[vivdownunder]

A drill bit stem pushed down the fuel line is a convenient way to block spillage.

Off the shelf in most garages with all the diameters needed.

Viv.

 

[bigjones]

Mine is 5/16" id, which I believe is correct for the later cars as well.

Thanks for posting Randall - you saved me fighting with 1/4".

I might even be tempted to use my "backup" electric fuel pump to transfer the fuel to another car.

Yes, I like that idea!

Jeremy - thanks for the link - I might get some just for that part of the line.

Viv - never thought of that - and I've got plenty of drill bits - all nicely blunt.

Cheers

 

[PeterK]

For years, I've temporarily used a wood pencil to block fuel lines.

 

[ekamm]

Golf tee works well too.

 

[mrv8q]

I'm surprised that 5/16ths seems to be the prevailing number; it's way too large for my just rebuilt carbs. Even 1/4 seems a touch loose; I can easily pull them off and on. I'm using a metric woven fuel line on mine, that hold very tightly w/o hose clamps.

 

[TR3driver]

I'm surprised that 5/16ths seems to be the prevailing number; it's way too large for my just rebuilt carbs.

That's because the original question was about the line on the inlet (glass bowl) side of the fuel pump. The line from the pump outlet to the carbs is 1/4" od. The original lines used without clamps were a bit undersize so they would grip; modern line pretty much requires clamps.

 

[TR3driver]

I know Gates recommends using SAE 30R9, which they call 'fuel injection hose', not SAE 30R7 which they call 'fuel and oil hose'.

Hmm, a leading hose maker wants you to buy their much more expensive hose instead of the cheap stuff. You don't think there might be a relationship there, do you?

 

[mrv8q]

That's because the original question was about the line on the inlet (glass bowl) side of the fuel pump. The line from the pump outlet to the carbs is 1/4" od.

Well, that explains that! True enough, I didn't read the post that carefully.....
Thanks, Randall!

 

[sp53]

Hi all I am new to the carbs without the banjo fitting and wonder how they kept them on in the day. I went to the lawn mower shop and purchased some Honda lawn mower fuel (perhaps ¼) line that just pushes on and it holds well on the ¼. The stuff is ten bucks a foot. The problem I am having is at the transfer point from 5/16 to 1/4 at the first bowl. I cannot seem to easily make that stretch with a short piece of rubber. Any ideas? What did they have there on the originals?
steve

 

[PeterK]

5/16 flex-line from the steel tank line (and/or shut-off valve) to the stub hard line on the pump, then 1/4 on the carb side of the pump to the carbs.

I used regular fuel line from my FLAPS.

 

[jdubois]

I know Gates recommends using SAE 30R9, which they call 'fuel injection hose', not SAE 30R7 which they call 'fuel and oil hose'.

Hmm, a leading hose maker wants you to buy their much more expensive hose instead of the cheap stuff. You don't think there might be a relationship there, do you?

Sure, gain of salt always needed... but if that was their only goal, you'd think they'd be pushing their even more expensive 30R14 which is *supposed* to be their ethanol safe 30R7 replacement.