I noticed yesterday that brake fluid is leaking from the front master cylinder.  It's leaking at the junction of the cylinder itself and the joint where the brake line starts.  does this mean I need to replace the line, the cylinder or both?

Could it just need tightened?  Maybe only needs new seal washers, only a buck or so each. 

Yep. Time to replace the crush washers. You will need 2.

Yea I'd start with the crush washers, then move on to the line then the master cyl. Any thing done here = bleeding the brakes. Might as well go to DOT5. Atleast it wont eat paint.
Cool.
Buddha.

I know this is probably a dumb question, but will replacing the crush washers require bleeding the brakes?  I'm assuming it will.

Yes.
It will be a lesser bleed ... like  ... you dont quite have to bleed @ the caliper. You can do a pressure bleed though, old ass fluid, I'd just replace it all but sucking it out te bottom, and chasing it with fresh dot 3/4 then finish and fill with 5.
Cool.
Buddha.

do yourself a huge favor and get ss lines while you're at it
its only 25 bucks, and it comes with crush washers, and immeasureably better brake feel

Buddha, you should have explained this better.  If someone inexperienced followed your advice they'd end-up with a brake system full of type 3/4 fluid and a reservoir full of type 5.

Oh, and tripleB, before you buy anything, just tighten the banjo bolt a little.  It may have just come loose.  If it doesn't leak and doesn't feel spongy you're done.  If it feels spongy you'll need to bleed it.

I'll try tightening it a little, but it definitely is leaking and more leaks when I apply the brake.

where can I find ss lines for $25?  the cheapest I can find them is for $50.

If I had some volume - maybe 10-20 I could crank em out for ~35-40. But as always, all of these projects have a ton of inertia ... I ave to have $ before hand, and people want details and this and that and pics ... yea pics ... we must see pics of the stainless brake lines. We dont want the thing to look any different from the pics.
Cool.
Buddha.

they have some for $25 to $40 at bikebandit from Goodridge but they are with female connectors.  I'm assuming I could throw a banjo bolt adapter ($6) on both ends and it would work for the GS.  Does anyone know if this would work? 

BTW, how long of a line should I get?

Yea, the banjo into female BS, total crap ... You need banjo into ferrule and fine thread ... that crap you got pics of is suitable only for harleys. Well it is shiny ... and thoe Idiots run them, and the bling bling bruddas run em on their extended blingarms.

Man, I am going to make these ... freaking preorder BS be damned ... There is a local nascar shop that makes em ... they did on my suggestion 3-4 years ago, but I bought 10 at that time. I might as well do it now, I prolly have enough bikes to use 10 ... 

Anyway, 29 or so inch should work ... 30 max ... and 89 actually has smaller even, like 27 maybe.

Cool.
Buddha.

they have the 30" in black for $32.

Screw that - try this - You dont want that wide ass thread with the conical end ... you want fine thread with a tail shaped end and it goes into a ferrule ...

This is swaged - may be better than threded or not ... never had either go bad IMHO ... but threaded can be repaired. Swaged cannot.

http://cgi.ebay.com/ebaymotors/HONDA-MOTORCYLE-STAINLESS-S-BRAIDED-BRAKE-HOSE-LINE_W0QQcmdZViewItemQQ_trkparmsZ65Q3a12Q7c66Q3a2Q7c39Q3a1Q7c72Q3a1171Q7c240Q3a1318Q7c301Q3a0Q7c293Q3a1Q7c294Q3a50QQ_trksidZp3286Q2ec0Q2em14QQhashZitem4145d77b41QQitemZ280344623937QQptZMotorcyclesQ5fPartsQ5fAccessories

Cool.
Buddha.

You can also check the info I just posted here:

http://gstwins.com/gsboard/index.php?topic=48602.0

Good luck! 

yeah i got mine from flandersco and shipping was like 2 bucks, because they're based in pasadena and i'm in la