Re: unpredictable brakes
Like Kevin said above, brake issues; especially pulling, are due to front end parts and bad brake adjustment. The hydraulics assuming the seal is still good is seldom an issue, which is why the factory uses hydraulics instead of rods and bell cranks like those used on horse drawn wagons and early cars.
Worn tie rods and the rest of the steering components are the usual suspects. But if you have a bad (rusted solid) self adjuster, or din't adjust your brakes shoes when new shoes were installed, it will also cause problems.