tropical36--are you referring to tire air pressure as the first thing to check? I think the F53 uses (and has always used) hydroboost brakes, rather than air over hydraulic of some sort, so that's the only somewhat relevant air pressure I can think of.
In my experience, a sticky brake caliper can feel like a pull to the opposite side when braking, when it's more accurately a constant pull to that side all the time...so check your right brakes as well as the left. Motorhome brake calipers are somewhat prone to getting sticky since they tend to sit unused for rather lengthy periods of time and possible accumulate corrosion etc. There are, of course, other causes of sticky or intermittent braking.