The Reservoirs on the handle bar was what I was referring to ?
Now i'm totally confused ???
You earlier said the “left” reservoir and there is no left brake reservoir on the handle bar. The left handlebar reservoir is for the clutch. Since you said “facelift” 2004, I am assuming you mean your bike has the iABS like my 2007. If that is the case, there are four brake fluid reservoirs, one for each brake circuit on the LT. These are: Front and rear control circuits and front and rear wheel circuits. The front control circuit reservoir is with the master cylinder on the right handle bar. The rear control circuit reservoir is under the seat on the right side of the bike and is cylindrical with a screw on cover. The two wheel circuits are on top of the ABS module as shown in the picture that John posted, which I think is of my LT from the looks of it. Ignore the red arrow as that is pointing to the ABS electronics connector. Look at the funnel which is, I believe, in the near side reservoir. I would have to look up now which is front and which is rear, but one is also taller than the other.
The fluid levels in the control circuits are not monitored, only the levels in the wheel circuits on top of the ABS module. The caps on these have breather hoses attached to them. Before you remove the caps to check or add fluid, THOROUGHLY clean all of the areas around and above the cap (subframe, wiring harnesses, etc.). I blow mine off with compressed air, then wash with soap and water and gently rinse (no pressure washers), let dry, and then blow one more time with compressed air. You want this area operating room clean before you remove the reservoir caps.
This is much more work, but the best way to fill these is to fully compress the brake pads in all calipers, use the funnel provided by BeamerBoneYard (I cut mine and added clear plastic hose as I could not get it aligned as it came) and then fill the reservoirs until the level is just below where the bottom of the cap will fit when screwed back in. If you do that, you will have enough fluid to completely wear out the pads and not trigger a low fluid level. Any less fluid, and you risk alarms as the pads wear down. If you don’t compress the pads and fill the reservoirs, then next time you compress the pads, you will make a mess when you push the excess fluid out of the ABS module when you compress the caliper pistons.