I am no fork guru, but does the manual say the quantity is 750mL or add 750mL after draining the current oil as best you can? I have read a few posts from people who did not disassemble the forks completely, thinking they could add the amount in the service manual since they drained them. A common problem is that all the oil is not drained out during a regular oil change, so adding the quantity mentioned in the service manual will sometimes mean there is more oil in the forks than there is supposed to be. I hope this makes sense to you.