What does the fuel return hose really do? - Off-Road Forums & Discussion Groups
Jeep-Short Wheelbase All discussion of short wheelbase Jeeps: CJ, TJ, YJ and JK

LinkBack Thread Tools Display Modes
post #1 of (permalink) Old 04-22-2002, 09:27 PM
Posts: n/a
What does the fuel return hose really do?

My 1975 258 carb and engine setup didn't have any such lines but when I installed a '76 304, it used a return line.

What's the deal? Do I need it?
Sponsored Links
post #2 of (permalink) Old 04-22-2002, 10:08 PM
Join Date: Aug 2000
Location: Iowa City, Iowa
Posts: 317
Thanks: 0
Thanked 0 Times in 0 Posts
Re: What does the fuel return hose really do?

Try searching on here about it, I know we were just talking about it the other day.

Just a brief overview, the return line, on a carbureted engine ,serves multiple functions:

Allows fuel to return to the tank, rather than over pressurizing and blowing the needle off the seat (with high volume/ pressure pumps).

Helps prevent vapor locking by allowing cooling fuel to circulate through the pump at all times rather than vaporizing in the lines and pump.

Helps reduce post fuel pump line pressure to help minimize wear and tear on the pump.

Bald_One is offline  
post #3 of (permalink) Old 04-22-2002, 10:34 PM
Posts: n/a
Re: What does the fuel return hose really do?

Oh yeah, the search function works now.

Sponsored Links
post #4 of (permalink) Old 04-23-2002, 07:45 AM
Jim_Lou's Avatar
Join Date: Dec 2001
Location: Belleville, Illinois
Posts: 11,449
Thanks: 15
Thanked 16 Times in 11 Posts
Re: What does the fuel return hose really do?

The thread you want is titled "Return line routing" or something close.
Jim_Lou is offline  
post #5 of (permalink) Old 04-23-2002, 08:02 AM
Posts: n/a
Re: What does the fuel return hose really do?

That was my thread he's talking about, I don't remember what the exact title was but search by my name, no more than two weeks.
post #6 of (permalink) Old 04-24-2002, 11:48 AM
Keyboard Implanted
Join Date: Sep 1999
Location: Southeast Iowa
Posts: 6,394
Thanks: 0
Thanked 0 Times in 0 Posts
Re: What does the fuel return hose really do?

[img]images/icons/tongue.gif[/img] I bought a used Suburban once and the goof-balls who had previously worked on it[img]images/icons/frown.gif[/img] plugged off the fuel return line in a very sneaky manner[img]images/icons/tongue.gif[/img] such that it did not show it was plugged.[img]images/icons/mad.gif[/img] That Sub ran like crap.[img]images/icons/frown.gif[/img] When I would pull up to the front of the auto parts and go in for something quick, I would have to grind and grind on the starter to restart the Sub, and then when it finally started it would fill the street with unburned fuel smoke.[img]images/icons/blush.gif[/img] Without that line the underhood heat expands the air entrapped in the fuel and pushes fuel past the needle valve, overfills the carb and fills the intake with raw gas.[img]images/icons/mad.gif[/img] The line; as was so perfectly pointed out; also reduces vapor lock by preventing the entrapped air in the fuel from bursting forth as the fuel passes the needle valve and depressurizes, which makes a bubble the size of a BB go to golf ball size and use up all the space in the carb float bowl.[img]images/icons/tongue.gif[/img] There is hardly anything that detroit ever dreamed up that is as beneficial as the fuel return line.[img]images/icons/tongue.gif[/img] Of course diesel engines have had them since DAY ONE.[img]images/icons/crazy.gif[/img]
CJDave is offline  
Sponsored Links

Quick Reply

Register Now

In order to be able to post messages on the Off-Road Forums & Discussion Groups forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:


Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

For the best viewing experience please update your browser to Google Chrome