If you find yourself needing to do repairs to an RV toilet it will be far easier if you simply remove the entire unit. This will give unlimited access vs the try and work by braille method. To that end utilize a 7/16" deep socket to simplify removal of the two nuts/bolts that secure the toilet to the floor.
Most but probably not all toilets are 7/16" so check yours. Some are easier to access than others, mine is a PITA but turning those nuts with an open end wrench, about a sixteenth of a turn at a time, is a very aggravating time consuming exercise.
You're welcome.
:B