odonnell

About a year ago I pinched the hardlines near the torsion bar when dropping the rear suspension resulting in a fuel leak from both the delivery and return lines (rotten bit of luck). I spliced in some rubber high pressure fuel line and it has been mostly fine but I think it is causing problems. I've been having random problems with starting that act like fuel starvation and seem to be mitigated when I move the rubber sections around - they obviously bend when driving around. Not super kinked or anything, but enough to where maybe it causes enough of a pressure loss to mess with the fuel injection. Pump, FPR, and filter are all relatively new.

I'd like to just redo the repair correctly by installing good used hardlines but am not sure what that entails besides the obvious. Rear suspension would come down of course since it runs on top of the torsion tube.

Is anyone running alternative fuel lines? Like stainless steel braided front to rear? I can't help but think stock would still be best but maybe there are better solutions out there.

Ijl53

I'm in the same boat, just saw two of my hard lines were pinched no leak or starvation issues yet but I'm looking for any ideas on how to repair it.

Tiger03447

For rust-free lines, there is a type of fuel line that is cupro-nickel. It bends easily for hand forming and is great to work with. You will probably have to put metric inverted flares on it to get it to go with the other lines, along with the appropriate metal fittings. comes in lengths, pre-cut with SAE fittings already installed. Or you can get the 25 foot roll...AZ has it as well as the other Auto stores. Required replacement lines in Maine and VT...due to rust pblms there. Or you can go to classic tube and get it done in stainless.

marc abrams

2nd for cupro-nickel or ni-copp. I got a few rolls from e-bay.

V2Rocket

i think you'd be ok with a good braided stainless line tucked up carefully into the body, maybe wrapped in thick rubber hose for added protection.

remember the hardlines are good for pressure and longevity but they are as much for ease of manufacturing the car.

Big E

3rd'd on the copper-nickel lines. Also called Cunifer among various other names. I replaced all the hard brake lines on my truck after one twisted in half attempting to replace the flex lines, and 8 (more?) years later, they still look basically new. A little surface "greening" but that can be removed in about 30 seconds. Can be bent by hand fairly easily too, and doesn't kink unless you really try.

This stuff seemed fairly rare back when I did the brake job, and in trying to find it I found a place up in MA that sold the stuff (fedhillusa.com) They have this great setup where you buy the line and then a box of fittings of various sizes. You use whatever you need, send the rest back, and they credit you for whatever you didn't use. Can also rent a real nice crimper that does a great job. I didn't have a single leak when I put it all back together. Still don't.

No affiliation w/ FedHillUSA, just a very satisfied customer many years later.

odonnell

Thanks for all the suggestions guys... so it's definitely feasible. How would you ideally handle adapting the new hardlines to the section near the firewall?

I.e. the hardline section that goes through the firewall and joins the rubber hoses in the engine bay. I don't know if they come out, or if the new hardlines need to be adapted onto them behind the firewall.

V2Rocket

on my car the hard lines are under the car the whole way and never pass through the firewall...same way on an '82 944 i put fuel lines on...???

marc abrams

A inverted 45° flared to female pipe Straight Adapter then a male pipe to barb fitting, Then fuel injection hose and clamps. Home depot got a descent stock of brass fittings but http://www.mcmaster.com/ got everything ever made.
McMaster-Carr also has hose-to-threaded female 45° flare adapter.

odonnell

I just realized my error, I haven't looked at them recently but I guess they just run up the inside of the firewall:




Sweet, good info. I know very little about this sort of thing so thanks for pointing me in a good direction. It doesn't look like this will be too extreme of a project.

odonnell

Want to revisit this project - I'm starting to really feel the need for new lines back there. Never done this before and have asked a few knowledgeable guys (thanks Tiger03447) for their advice. Posting the concept here, hoping for improvements and refinements.

So the section that I replaced is between the trans crossmember and approximately under the rear seat area, where the hardline straightens to run to the front. The fuel tank vent line is still intact - the delivery and return lines are affected.

Line choice
I am leaning toward the cupro-nickel stuff you guys are suggesting... unless SS braided isn't as expensive as I'm thinking? I have no idea how much it would be for say, 10 feet, with the correct fittings. I'm thinking about routing the new lines above the torsion carrier in the same place the torque tube does, and then angle them back to meet the stock hardlines. Need to get prices.

Termination
For securing the lines to the front-most junction, I've been told a normal flare should be fine... maybe a double flare worst case scenario. For the rear-most functions, there is an option. I could do the same thing (flare) and connect to the hardlines, or replace it all the way back to the fuel pump/fuel tank. There is a threaded fitting for the check valve tube section that could be directly mated to this replacement section.

Anyone have input? If I do the SS braided line with these fittings, it may have to be a custom order and I have no idea what I would be getting myself into money-wise.

odonnell

Alright, just ordered the parts. I decided to go with flare fittings for the delivery line - found some gasoline rated 3/8" 37 degree unions and associated hardware that should work fine. For the return line, I'm using compression fittings that are rated for gasoline. I know flare fittings would be better but I wasn't having much luck finding them for 5/16" line and still be gas-safe, plus it's a very low pressure line.

Gotta get some copper nickel line...any places sell it by the foot? I'm not wanting to buy 25' rolls or 2' sections.

Also need a recommendation on a flare tool that comes with a 37 degree die without breaking the bank...don't want China Freight garbage

g-50cab

BAT in Sarasota has many of the fittings (including Metric)

http://www.batinc.net/mocal-central.htm

The flaring tool you need is - Ridgid 83037 45° SAE Ratcheting Flare Tool for 1/8 - 3/4" Tubing (458R)

I used SS hard line tubing from McMaster Carr for my 911 Lines are
2 Each 89895K27 Type 304 SS Smooth-Bore Seamless Tubing 3/8" OD, .305" ID, .035" Wall, 6'Length

Len Cumming supplied the M16 x 1.5 fittings for 3/8" pipe Len@Autosportengineering.com

I also had stainless steel flexi lines to connect to the hardlines. Kinda like the safety aspect when dealing with gas.

marc abrams

He's looking for a 37 degree flaring tool for that AN stuff.

marc abrams

Not in a million years would I ever trust a push on hose barb without a clamp for my garden hose let alone a fuel line hose.