Maybe the GMM says roll the aircraft forward till that part is on the bottom
A few other things about automotive brake fluid. DOT3 boils at something like 450degF aircraft brakes can get a lot hotter than that. Also it contains alcohol making it a little more flammable.
Does anyone know what Russian aircraft actually use in thier hydraulic syatems? Is it petroleum based like 5606 or something with a phospate ester base?