The Chicken Man
Active Member
No worries about questions, that what the forums are all about! That said I'm not a technician, I can only offer advice based on the experience and knowledge that I have.
According to the manual, you will want to do both in the order it instructs. So, start with the procedure that only generates a single pulse ("Hydraulic unit operation test 1" starting on page 4-59) then do the procedure that pulses for 1.5 seconds ("Hydraulic unit operation test 2" starting on page 4-60).
That said, if you are cycling the ABS unit for the sake of bleeding out old fluid or air, I think you really only need to focus on "Hydraulic unit operation test 2". I believe both tests are physically doing the same thing, the second one just does it for a longer period of time. By that logic, the second one would be better because it would move more l fluid. So, the first one would be more for testing the ABS and the second would be more for moving fluid. But the service manual does not explicitly state that so I cannot confirm. Either way, can't hurt to do both.
My thoughts on this: I think the authors' intentions are just to get us moving new fluid through the ABS unit. What I do know for sure is that old brake fluid can get skunky and corrosive; clogging, gumming up, and damaging things. Especially smaller more sensitive components. I think authors included this step just make sure that people like me, who never ride hard enough to activate the ABS, are not letting old fluid sit inside the pump forever. So if you did the tests and bleed your fluid, I say you're A-okay!
