Maybe I'm misunderstanding.so please forgive me if I have, but I feel one should of course use the Vacuum fluid removal on any process, whether any type of cleaning step, or the final rinse step. Vacuum removal is much more efficient, getting more of the contaminants, and filthy fluids off the record this way That's the whole purpose of these RCMs.
I am well aware of many purists in this group, who probably take cleaning much more seriously than I do, and hence their reasons for upgrading from RCMs like the VPI-Nitty Gritty, those that possess a slotted wand, and move on to much more costly-sophisticated machines, like the Loricraft, Monks, which are said to reduce the possibility of cross contamination (As well as possible abrasion from the wand contacting the record).
While the "cross contamination" issue, even though fairly slight, is probably a real one with these lesser machines, this issue can be lessened considerably, by the simple use of spare vacuum wands. A simple swap that takes about 3 seconds, and the cost for spare wands is not overly expensive.
I won't go into the other benefits of the string feed machines like Loricraft, as their owners well know their advantages, and disadvantages, which to mention a couple, is more meticulous upkeep-maintainence, and a bit longer cycle time per step.
We havent heard back from the OP, to confirm what the possible causes were, but (and again, I'm guessing cause I don't own one of these), but others may be correct, the wrong brush on board, or improper positioning of the brush?
Doesn't the brush on the 17/17F just clip into a holder? Meaning, it is basically the exact same brush, that comes with the 16.5 RCM, but held by a bracket? Mark