Wear at the accumulator bores in AS66RC, AS69RC and RE6R01A units is very common. The B1, B2, K1, K2, and K3 accumulator pistons are all the same size and are used during apply of the clutches to ease the engagement of the apply component. Wear at the valve body bore allows apply oil to exhaust, resulting in harsh or delayed apply, burned clutches, or slipping and flares in the associated gears. S0nnax B1, B2, K1, K2, K3 accumulator piston kit 122740-13K incorporates an O-ring for positive sealing, even in worn bores. This one kit will work in any of the five bores.