steel gas line size

[KJM]

just noticed a small leak where the steel gas line enters the carb on my 1978 merc 164 l6. I was going to replace the line and fittings and was wondering what the size of this line is. also wondering if a steel brake line would serve the same purpose?

 

[Scott Danforth]

for all intensive purposes, it is a steel brake line. bring a section with you, should be 3/8" line with a 5/8 thread on the inverted flare nut

 

[KJM]

thanks for the info

 

[NHGuy]

Yes, get a tube bender and a flaring kit. Go make it to fit.

 

[KJM]

my tube bender was my leg, its the flaring kit that's a little more expensive! I have it ready it go in except I need to cut the fitting off the old one where it attaches to the fuel pump, put it on the new one and then flare that end. in the meantime I realized the old fuel line just needed to be tightened up near the carb. I guess I got a spare now.

 

[Fishermark]

Just for future reference - fuel/brake line comes in so many lengths you should never have to cut and flare it. Buy a little longer than you need if you don't have the exact length available and bend it in a way that it fits.

 

[KJM]

length wasn't the problem. I needed to take the fitting off the old line that fits to the fuel pump and put it on the new one. that can't be done without cutting a flared end off both lines.

 

[alldodge]

Fuel line should be double flared, and you can pickup a flaring tool at auto stores for $25
http://www.autozone.com/test-scan-a...le-flaring-tool-set/864647_0_0/?checkfit=true

 

[alldodge]

Also don't see an issue using rubber type A1 fuel line with barbed fittings. Just don't use rubber fuel line over smooth steel line (cut off and slide hose on)

 

[Scott Danforth]

I thought everyone has a double flaring tool in their tool box.... right next to the pipe taps and dies, 4 different tubing cutters and the tubing bender. that is in the drawer right above the hammers (all 15 of them)

if the tube was leaking, I would replace the whole thing from the fuel pump to the carb.

 

[Fishermark]

length wasn't the problem. I needed to take the fitting off the old line that fits to the fuel pump and put it on the new one. that can't be done without cutting a flared end off both lines.

What type of fitting does your fuel pump require that you need to reuse the old fitting?

 

[KJM]

not sure what i'd call it......its larger then the end that goes into the carb, the brass fitting on the new line fits there fine. this other end has a larger piece that can be screwed apart and has a rubber o ring or seal in the middle. could probably buy a new one but I would still need to cut the flare off the new line to get it on and then reflare it. the local napa autopart store here told me a flaring tool was about $70. the old one stopped leaking after I tightened it up so i'm in no hurry with it now. I think most of my problem with the engine starting to stall after a half hour use was due to an extremely dirty spark arrester as well it was probably loosing some gas at the leaking fuel line and/or sucking in some air bubbles. anyway the problem seems to have gone away.....

 

[Baylinerchuck]

I know the fuel pump on my 4.3L is a male 3/8 flare fitting, and the end of the 3/8 steel line is a female. When I replace my fuel line I used steel brake line from NAPA, cut one end off, and used the flare nut off the old line to connect to the pump. The carb end used the standard 3/8 flare male that came on the steel tube. Also Harbor Freight sells a decent double flare tool pretty reasonable. Now I have one, but it's not next to the hammers.

 

[CraigBarnard]

If you can find copper/nickle line i would use that.
It will not rust like the steel lines do.
Easier to bend also.
I use it on all my brake line repairs.

 

[KJM]

I never heard of that kind of line but will keep it mind for next time, thanks

 

[johnkom]

My local O'Reilly's will loan me the flaring tool.

JK