SS brake line install - leaking hardline connection
 

TL;DR I started the installation of some braided SS hoses today. I worked from the back towards the driver font. Bled everything and noticed the driver front is still leaking.

Everything went really smoothly until we got to the driver front connection. The 10mm nut on the hardline connection was tight. But I mean seriously tight. After we eventually busted it loose with a strong grip on the hose and a lot of swearing, we did that line, bled it, and thought we were done. But there is still a slow leak on the softline-hardline connection.

Now I'm thinking that the reason it was so tight was because whoever fitted it originally overcompensated for something. The rest all felt consistent - it was just this one that was ridiculous. It doesn't matter how tight we fit it, there is still a leak, so I think the hardline might be bent and not lining up with the hose on the inside. Maybe the original overtightening caused the hardline to kink and now it won't go back to the exact fitment. Thinking back now, the retaining clip was also difficult to remove even after the bolt was loosened.

Pics for comparison: http://imgur.com/a/V1jsO. I wish I had some before pics to see whether or not it was bent while loosening or if it was bent already. Alas, I didn't, and we'll never know.

Here are 2 pics from the album posted for convenience (although there are more in the album):

http://i.imgur.com/pNqin79.jpg

http://i.imgur.com/Oc8BggV.jpg

Also - these connections do not have to be that tight. The other ones were barely more than hand tight and they sealed up nicely. I'm pretty sure it was either overtightened or rusted to shit, but it doesn't look that bad and the car is pretty new.

My current ideas for troubleshooting this further:

• Try fit the old rubber hose and check for leaks
• Remove the other front SS hose, fit it, and check for leaks
• Threadlocker on the hardline bolt to get a better seal
• Try straighten out the hardline (don't want to do this)
• ???

I'd really hate to crawl to the dealer with my tail between my legs and ask them to replace the hardline out of my own pocket (if they even agree to do the work). On that note - how dangerous would it be to drive with a slow leak? I'm assuming quite dangerous, but when we bled it, there was good pressure going through the entire line (and no bubbles).

If anyone has any suggestions as to what to try, or who to ask, I'd appreciate it a lot.

Tighten it as much as possible before putting in the clip, this will let it thread is easier.

Thanks :). Unfortunately all this business was without the clip. Putting in the clip and fiddling further also yielded no results.

So you don't think the slight bend in the hardline shown in the photo is a problem then? The nut should align the hardline as it is tightened and eventually squeezed against the softline, right? Meaning that if there is a threading issue, the hardline won't make as good contact as it needs to?

Not sure which type of flare is used on this car, if it's a normal double flare it's quite easy to fix. If it's a bubble flare you're kinda screwed...

Thanks :) How do I tell, and why would I be screwed? If it's a "normal double flare that is quite easy to fix", how would I go about fixing it :)

I'll try and get a photo tomorrow.... although currently I'm planning on pre-emptively trying to make a booking with a Subie dealer near and limping over there :(

This is annoying, because the job was quite easy and went quite smoothly otherwise.

Update: It works!! (For now. I hope. Will keep an eye on it)

I tried re-fitting the old rubber hoses. They went in fine without leaks. So I made sure to clean the threading as well as I could by blasting it with copious amounts of brake cleaner and penetrating oil and letting it sit for a bit. Then before re-inserting the SS lines, I applied a bit more oil on the thread for lubrication (taking care to wipe away excess that it doesn't get in the lines). I re-inserted the SS lines and still had a leak. YARRGH#$$%. So I tightened it down a bit more using a vice grip to hold the lines and hand tightening with a flare wrench as tight as I could (one tool in each hand - having a buddy helps).

And now it's dry :|

I almost don't want to believe it. I pumped the pedal a bunch of times, came back to it, repeated, and it still looks dry. I'll keep an eye on it, but I think the threading was an issue. Will post back here if any more sadness occurs.

Sounds like it may have been cross threaded from the factory or the threads on the SS Line may have been slightly off or had a burr on it. Keep a keen eye on it.

-mike