Daphne,
You generally have control of your maintenance plan when you make it. You can play with the schedule until you get something you like before you buy it. Doing bricks during maintenance is not what we recommend. We would have put some in there for you if we thought it is what makes sense to do this far from your main goal race.
For ideas as to what you shuuld do during maintenance with an Ironman looming this summer you may want to read my winter training article below.
http://www.markallenonline.com/offseason.asp
If you still want to do bike and run workouts. You are in charge of your own destiny of course. Then do the swim another day and do one of your short runs that day but not as a brick. Best to recover and then run a little faster at a nice low heart rate.
Luis Vargas