FORD 2011 F-550 v.3 - Manual (Page 391)

BRAKE FLUID
• Vacuum boost system
• Hydroboost system
The fluid level will drop slowly as the brakes wear, and will rise when the
brake components are replaced. Fluid levels between the top of the MIN
and MAX lines are within the normal operating range; there is no need to
add fluid. If the fluid levels are outside of the normal operating range,
the performance of your brake system could be compromised; seek
service from your authorized dealer immediately.
MIN
MAX
Maintenance and Specifications
391
2011 F-250/350/450/550 (f23)
Owners Guide, 3rd Printing
USA (fus)