Motorcycle Questions? Ask a Mechanic.
Hi and thank you for your question.
I would like you to check something for me. Before working with brake fluid and the likes, make sure you remove all painted parts or properly protect them from brake fluid contact. This includes all plastic parts such as but not limited to clear windshields and colored lenses as well.
I would like you to remove the line from the master cylinder, and with the cap off the M/C, place your finger over the end of the M/C where the line connected. Hold pressure with your finger at that point, and slowly pump the clutch lever and see if you feel any hydraulic pressure at that point. It is ok if it pushes some air out at first, and after a few strokes is pumping straight fluid.
Let me know your test results please.
Thank you for the additional information.
That is very good news that you have pressure being developed at the M/C. Now the next step is to put the clutch line back on the M/C and connect it to the slave cylinder, but start by bleeding the system at the banjo bolt at the M/C. Why we do this is simple. Air is lighter than fluid, so as the fluid gravitates towards the bottom, air is pushed up, unless it is trapped. By starting at the upper banjo bolt and bleeding all of the air out there, you are allowing the air to escape from the system that gets trapped at that point. You bleed the banjo bolt exactly like you would the bleeder valve on the slave cylinder. Pump the lever a handful of times, hold it, crack the bolt loose about 1/4 turn to let air out, then snug it back up. The key here is you don't have to go to full torque every time on the banjo bolt. Just snug enough to prevent a leak. The less torque you put on the banjo bolt, the easier it is for you to control that 1/4 turn loosening. IF you get it too tight, you end up pulling so hard you go a half turn or more. Once again, protect all plastic and painted parts from the brake fluid. After you are sure you have all the air out of that joint, do the same procedure at the banjo bolt at the slave cylinder. Repeat the same procedure until no air (bubbling or spitting) is detected. Finally, bleed the system at the bleeder valve on the slave cylinder. Check for proper clutch operation. If it doesn't work the first time, you may have to repeat this a couple of times, but I assure you, the long and short of the problem is air trapped in a very sneaky place.
If you have any more questions, feel free to ask.