Unless your brakes were already hot such as coming down a long grade the brake fluid should not be an issue. You should change your brake fluid every two to five years depending on how often you use the RV. Use either DOT 3 or DOT 4 depending on what the chassis manufacturer recommends. Never use DOT 5. My emergency stop rule is 'pedal to the floor and I hope the ABS works along with a quick prayer'. Afterwards I turn off my hearing aids so I only see my DW's lips moving and I'm never sure what she is saying.