fuel line between separator and pump

Cptkid570

Ensign
Joined
Oct 18, 2005
Messages
967
Hey everyone,
My current set up on my 1985 5.7 liter mercruiser is:
Tank, rubber fuel line, fuel/water separator, metal fuel line, fuel pump, metal line, carburetor.

I had to change out my fuel pump and the metal fuel line between the fuel/water separator and fuel pump stripped.

Is it ok to use rubber fuel line between the fuel/water separator and the intake side of the fuel pump?

I'm under the impression that the only place that the line really has to be metal is between the fuel pump and the carb... but, I want to make sure..
 

KaGee

Admiral
Joined
Aug 14, 2004
Messages
7,069
Re: fuel line between separator and pump

The fuel line must be hard I'm pretty sure. I redid my own using steel brake line and renting a double flare tool.
 

95yj

Petty Officer 1st Class
Joined
Feb 21, 2007
Messages
279
Re: fuel line between separator and pump

Check this out: http://newboatbuilders.com/pages/fuel.html

It states that you can use A1 fuel line between the fuel pump and the carb, or anywhere for that matter. The fitting you are attaching them to must so most of the holding of the rubber line, barbed end or such, and you want to double clamp everything that's under pressure.

Just a guess, but anything that can hold up to brake line pressures ought to be able to handle fuel pressure. I do know that the line cannot have a seam in it and you want to watch out for materials that will cause a galvanic reaction.
 

wcsparky05

Petty Officer 1st Class
Joined
Feb 5, 2007
Messages
204
Re: fuel line between separator and pump

absolutely should be rubber gas/fuel line. use screw down compression clamps. same as you see on your washing machine, maybe. the ones with the slots in them. no reason to be rigid metal.
 

Cptkid570

Ensign
Joined
Oct 18, 2005
Messages
967
Re: fuel line between separator and pump

I've only heard that the metal has to be used between the carb and the fuel pump. The rubber line that I bought came from an auto parts store and is rated for fuel injection systems. (was like $4 a foot), so I'd imagine it will be ok to use it on my boat between the separator and input side of the fuel pump.
 

95yj

Petty Officer 1st Class
Joined
Feb 21, 2007
Messages
279
Re: fuel line between separator and pump

Rated for automotive fuel injection doesn't mean USCG approved. The A1 line that is USCG approved has to go through a 2.5 minute fire test and also has stricter vapor leach through characteristics. Any rubber fuel line in the boat needs to have USCG stamped on it.
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: fuel line between separator and pump

is rated for fuel injection systems. (was like $4 a foot), so I'd imagine it will be ok to use it on my boat between the separator and input side of the fuel pump.

Wrong assumption, it may cost $4 a foot and be for ruel injection, but that doesn't make it pass the fire test, and that is what the A1 hose is certified for.
 

Cptkid570

Ensign
Joined
Oct 18, 2005
Messages
967
Re: fuel line between separator and pump

Ok, I don't know a lot about hoses. Is the A1 hose a rubber-type of hose or metal?

As long as it's the coast guard certified....Is it ok to use a rubber line in this area (between the separator and input side of the fuel pump)?
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: fuel line between separator and pump

Fuel Hose


Yes it can be used on the suction side of the fuel pump.
 
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