I had a 2005 Fleetwood Expedition that I installed a Brakemaster on several years ago. There is no open ports. You have to tie in on the SERVICE side of the brake can on the rear. I used the passenger side, but either will work. It isn't hard, but you have to ensure you are on the service side and not the park side.
You will need to get under the coach and take the airline off the can while having someone press the brake. You want the service side which is the side that you will get air on when brake is applied.
If memory serves me correctly, the install manual addressed this and how to do it on the one I had.
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