When I installed my Kawasaki disc brake set up a few years ago I had a devil of a time getting all the air bubbles out, and after hours of pumping/bleeding, pumping and watching the bubbles rise in the master cylinder, I achieved a great handle.
I took the calipers and MC off, cleaned the system (hate to admit I had not replaced fluid for a few years and the brakes went soft). After a couple of hours on YouTube once again educating myself on bleeding discs, I refilled the system with Dot 5, and recall a sentence that said. 'getting the air bubbles out of a Dot 5 system is difficult'. Thus I filled the calipers with no hose on. Then I made a plug that went half way into the banjos and carefully dripped fluid into the hoses before attaching them to the MC. Then I finally filled the MC. I pumped just a bit and got a handle! I thought I had beaten the system. Half hour later, the caliper handle was coming too close to the hand-grip, so I bled the system in the normal way. Same thing happened.
So I reverse bled them from the caliper upwards. Same thing again, caliper came too close to the bar.
I still have the same problem, I get a good handle that lasts for about an hour, and then the bubbles do their thing and create an air pocket(s). Just a couple of pulls on the handle returns the system to normal, feels great.
I think I have all the bubbles out, and it seems as though they are asleep for a time and re-awake after an hour or so.
The last time I did this operation I pulled the MC handle and watched very few bubbles, ever so tiny, rise. I did it over and over, and ultimately got a good handle that lasted. Seems as though I may have to repeat the process. I think the dual hose banjos may be the root of the problem and now I'm tapping on them, wiggling the hoses and saying, "This is really getting old," as I pull and release the MC handle.
I took the calipers and MC off, cleaned the system (hate to admit I had not replaced fluid for a few years and the brakes went soft). After a couple of hours on YouTube once again educating myself on bleeding discs, I refilled the system with Dot 5, and recall a sentence that said. 'getting the air bubbles out of a Dot 5 system is difficult'. Thus I filled the calipers with no hose on. Then I made a plug that went half way into the banjos and carefully dripped fluid into the hoses before attaching them to the MC. Then I finally filled the MC. I pumped just a bit and got a handle! I thought I had beaten the system. Half hour later, the caliper handle was coming too close to the hand-grip, so I bled the system in the normal way. Same thing happened.
So I reverse bled them from the caliper upwards. Same thing again, caliper came too close to the bar.
I still have the same problem, I get a good handle that lasts for about an hour, and then the bubbles do their thing and create an air pocket(s). Just a couple of pulls on the handle returns the system to normal, feels great.
I think I have all the bubbles out, and it seems as though they are asleep for a time and re-awake after an hour or so.
The last time I did this operation I pulled the MC handle and watched very few bubbles, ever so tiny, rise. I did it over and over, and ultimately got a good handle that lasted. Seems as though I may have to repeat the process. I think the dual hose banjos may be the root of the problem and now I'm tapping on them, wiggling the hoses and saying, "This is really getting old," as I pull and release the MC handle.
