My Car:
1997 Civic HX MT
290k miles
Due to the Pandemic I let it sit for 2 years, when I re-started it two years later the brake lines burst underneath the car and the fuel lines that run with them are quite rusty (underneath the car area only).


Questions :
1) To fix a rusty hard fuel line under my Civic, can I cut out the section and fix it exactly like a brake line ? That would be a new piece of hardline spliced in with a double inverted flare with tubing nuts into a inverted flare Union ? I have yet to see anyone on youtube etc. fix a fuel line with the exact same connections as a brake line and was worried there was a reason that I wasn't aware of.

2) What are the tube sizes for the 3 fuel-related lines ?

4) I was going to install a new set of hard fuel lines from lines to go and replace all the brake lines (front engine bay included) with line I am making with Ni-CU tubing flared myself. However I am now seeing that running the lines up from underneath the front of the car into the engine bay is a nightmare and seems like I have to remove the subframe to do so. Has anyone run all hard brake and fuel lines to the engine bay without removing the subfraem ?
5) How hard is it to take off the subframe ? What are some pointers to look for when taking it off ?
I've put "Free All" on all the subframe bolts this last week and they are actually all moving and not breaking. I know I will have to remove the steering rack but seems like a ton of suspension (along with the tie rods that are already coming of) have to come off.

Thanks in advance for all of your time.

 

1. Yes, the approach to working on both the fuel and brake lines as far as tools to use would be the same - Though I think you'd want a single flare tool for both and not a double flare, but that may be dependent on what fittings you're using to splice it all back together.

2. I believe fuel supply is 3/8" and vent/return is 5/16" but if you can confirm with a tool beforehand that'd be ideal because I don't remember exactly what I used for my car.

3. It would be extremely hard to install new hard brake lines without removing the subframe, especially assuming the engine is still in the car. I would not recommend trying it.

4. Subframe is moderate effort to remove, but you can actually pull it while keeping your tie rods and brake disks in place.

You'll also need something to support the rear of the engine as the rear T bracket/mount is on the subframe, if you have a hoist it would be easiest to get a bit of tension from above to suspend that weight.

In your position I would also consider going for AN lines instead of hard lines at least for the fuel to simplify the job of running them where they need to go.

 

Thanks for the reply. I have some questions regarding the quoted parts below:



My Questions:
1) I already have all the brake line flaring stuff and hard line. I have All double inverted flare nuts and unions. I would have to go out and buy single flare stuff if I were to go that route. Is there any reason for me to use single flare over double flare in terms of physical engineering?

2) I already have the tie rods off as I was going to install new inner and outer rods anyhow (and I have to stake the inner tie rod lock nut on all 4 sides). If I choose not to do what was in that video link, after removing the steering rack, how would you go about the rest of the job removing the subframe ?
Note that having removed the rack implies I removed the PS lines and the tie rods only. So any info as to what suspension stuff to remove would be very much appreciated.