Jump to content

Need a little help on replacing some hard lines

Recommended Posts

Just an FYI my MJ is an 86, 2.5 with TBI.



SO I started to redo some ugly brake lines last night, and naturally...one thing leads to another...


As I'm pulling the lines out, I notice all the other lines (fuel lines and return lines) at the crossmember are prreeeeetttyyy rusty.


I just picture myself with rock solid brakes, springing a fuel leak and having my new to me MJ go up in flames! So I want to replace those lines too before I start driving it.


The brake lines are 3/16th, and it looks like the fuel return line is the same diameter, but the other main fuel lines (2 of them?) look larger, 7/16 or even 1/2"? Just wanted to get some opinions on replacing those lines. I'm fair at flaring lines, brakes are one thing, but fuel makes me a little more nervous and I really don't want any connections in there to be available for future leaks/problems.


What should I be doing to replace them? Using hardline? or some kind of braided line maybe easier? The fuel filter needs done as well, so everything fuel filter fwd is going to be replaced. Thanks for any insight.

Link to comment
Share on other sites

:agree: with the brake lines


If you want to redo the fuel lines, I would only do the lines around the filter / cross member area, and stay away from the quick-connect fitting. The fuel lines have a bubble flair for the soft line to slip over and get worm clamped on, even if you just use some soft fuel line, your getting rid of the rusted steel lines ;)


Off the top of my head, the supply line should be 3/8" and return lines 5/16".

Link to comment
Share on other sites

Thanks for the replies guys! I am pretty good with a flaring tool, I just re did my rear brakeline, and am about to do new MC/booster.


I was just a little more nervous about the fuel. So would it be better then to cut out the bad section (probably about 2' I would take out) and replace it with a quality connection hardline, OR just cut it out and use soft line in that section?


And I think your right about the hose sizes, the return is definately 3/16".

Link to comment
Share on other sites

The more hard line the better IMHO. It doesn't rot on the inside like rubber will eventually, it isn't pinched or cut easily, and most of the steel line available at the parts stores is coated so its not gonna rust away instantly or anything. Plus if you're replacing any part of the high pressure line from the pump you shouldn't use plain old fuel hose as its not rated for the kind of pressure fuel injection pumps put out. Dedicated fuel injection hose is the correct way to go and its easily twice as expensive. I'd just use sections of hose for the connection to the fuel sender and up to the rail and keep the rest steel.

Of course hose is much easier so its your call :waving:

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


  • Create New...