FD100/115-5 and FD135/150E-5 wherein detailed instructions are provided for a pre-operation testing procedure to ensure that the brake accumulator is properly functioning. (Ex. P-1, p.25).aquot; It is a simple two step test. The operator pumps the brake repeatedly with the engine off until the hydraulic brake ... The Komatsu maintenance manual identified and admitted in evidence as Petitionera#39;s Exhibit No.