I've got a 03 fatboy. I just replaced the front brake pads, while doing it I removed majority of brake fluid and replaced with fresh. My question is in the service manual it says to fill within 1/8 of an inch from gasket surface. But no matter how you stand the bike or turn the bars the reservoir is never level, so where in the reservoir do you measure the 1/8" and with the bars straight or turned to the left, bike on jiffy stand or standing straight up. Also I never noticed when I removed reservoir cover that it is wedge shaped, I'm guessing that the thicker part of wedge goes to the outside of the bars to accommodate fluid level? Would appreciate any and all help in this matter. Thanks

 

This is how I do it, ..... with the master cylinder as level as I can get it, add a little fluid at a time to the reservoir and each time I place the cap on loosely and watch the little window, and once the window goes dark I add just a little more fluid.
This way there's enough reserve fluid to take up for worn brake pads, but any more loss than that from the reservoir would show in the little window.

A little too much fluid and a few months from now you'll have paint eaten away around the gasket and corrosion.

I don't recall the gasket being thicker on one side.

 

I have found that for the front master cylinder, the bike needs to be on the jiffy stand and handlebars with a lean to the left.

 

Thanks for the info. unfortunately mine does not have a window to check, you have to pull the cap. The cover itself is wedge shaped, not the rubber gasket. my fault for not being clear. If anyone has the same style reservoir cap I'd be interested in hearing from them. Thanks again

 

The wedge on the cap, the fat part of mine goes to the outside of the bar, so that in riding position the top of the cap is nearly level.

 

Thanks that's what I guessed. I put it back on like that. Thanks again