Liqui Moly ATF Additive, Seal Conditioner for Automatic Trans and Power Steering 250ml

Liqui Moly ATF Additive (part 5135) is a seal conditioner and friction modifier you add to the automatic transmission fluid or power steering fluid. It swells and re-softens rubber and plastic seals that have gone hard and brittle with age and heat, which is what stops the slow weeping leaks at the pump shaft and case seals without pulling anything apart. One 250 ml tube treats a typical transmission fill.

On the bench or in the driveway, the usual play is a drain-and-fill with the correct spec ATF, a new filter, then the whole tube of additive with the fresh fluid. It cleans out the valve body passages, revives the fluid's frictional properties, and smooths out shift feel and torque converter shudder on higher mileage units. On power steering it quiets the moan and whine that comes from a worn pump and dried seals.

This is a maintenance and stop-leak aid, not a repair for mechanically failed clutches or a slipping band. It is at its best on aging seals, minor seepage, a noisy power steering pump, or a converter that has just started to shudder. It mixes with conventional and full synthetic ATF and Dexron/Mercon type fluids.