TOPMAX AUTO TRANSMISSION & ENGINE CARE is a synthetic additive designed to stop leaks in ATF’s, power steering fluid, engine oils, gear oils and hydraulic installations. The additive’s technology softens and expands old seals to recover to “new” seal performance. Oil leakage caused by hardened, dried out brittle seals can be solved and prevented. TOPMAX AUTO TRANSMISSION & ENGINE CARE targets valve stem seals, crankshaft seals, dust seals, oil filter O-rings and oil pan seals and all other plastic or rubber based seals.