The kit seals the critical circuit pressure losses in the valve bodies.
Many of these vehicles have had defective OE converter-clutch linings causing the slip. Many of these have since been resolved so this issue doesn’t come up as much on ATSG’s technical help as it used to.
But when they do come in, we explain the way to verify a defective converter lining. It is by checking TCC pressure on the transmission’s one-and-only pressure tap.