Industrial 4JMY8 Mechanical Seal

Dayton 4JMY8 Pump Shaft Seal Kit is a 3/4" mechanical shaft seal assembly designed as a direct replacement for Dayton pumps with a 3/4" shaft. The kit includes a carbon-faced seal with stainless steel internals and an O-ring, delivering a robust, reliable seal to prevent leakage along the pump shaft. The Mfr Part Number is 4JMY8, and in some catalogs the seal is listed as Seal Type 21. This Dayton part is intended for maintenance and field-repair use, providing a complete seal solution without needing separate components. Typical applications include small to mid-size centrifugal pumps where a 3/4" shaft seal is required, including industrial and commercial pump systems. When replacing, confirm the shaft size (3/4"), verify the seal type (Type 21 in catalog listings), and ensure material compatibility with the pumped fluid to achieve proper sealing performance and seal life.