December 09, 2013
Wear at the accumulator bores or on the accumulator piston critical diameters in Toyota/Lexus U660E/F, U760E/F units is very common. The C1 accumulator piston is used during apply of the C1 (forward) clutch. Wear allows clutch apply oil to exhaust, resulting in harsh or delayed forward engagements, burned C1 clutch, or slipping and flares in forward gears. Sonnax C1 accumulator piston kit 47740-12K incorporates an O-ring for positive sealing, even in worn bores.
Sonnax valve body layouts provide a detailed overview of individual units making it quick and easy to determine what’s available for the specific valve body you’re working on. See all Sonnax valve body layouts.
A vacuum test at the port indicated fails to hold at least 18 in-Hg (Figure 1), or visual wear in bore or on the piston is detected (Figure 2).