I have a 02 954 and keep getting air in my front brake line. It is wierd I have the bike stored in my shed and brakes are fine. After a month sitting in shed there is air in the line. Any idea's what could be causing this?

replace the crush washers for starters just in case.
and get yourself a mityvac. them things rock

also if you don't have braided front lines,, Do It! best mod for the 954 besides a damper

Like that brake line advise. I'll have to get sum thos,,that rock.

Is your fluid reservoir full or is the gasket on the lid damaged or misaligned. Check all your fitting to make sure they are tight. Look for obvious leaks at the master cylinder, fitting connections, hoses and the caliper cylinders. Fill the resivour up and bleed the brakes.
Brake fluid needs to be replaced every so often. A sign is that it turns gets darker in colour. Old fluid will reduce the life of your seals.
Make sure that the bleed nut is tight when you finish.
If the air comes back I would guess that your master cylinder or caliper cylinders have a leak. From there you would need to get a rebuild kit from a dealer or have them do it.

You can go to ebay and there is a guy on there who has braided lines in different colors (Galfer). I have them and their great.

The vacuum thing is nice, but age old "open, squeeze, and shut", works just fine. You just have to get the order right. I did mine about a week ago. Nothing better than fresh fluid as a confidence builder. Sounds like you have a bad seal somewhere.