Armstrong 4280 S-11-1/2 Repair Kit




Kit to replace seal in Armstrong Model 4280 New Style circulator.

New style circulator can be determined by the discharge line being in the center of the volute. The old style design has the discharge line offset to on side.

Includes 11-1/2" casing gasket

Shaft shaft sleeve

Mechanical seal

Correct seal replacement kit for:

4280 4x3x11.5,  with 1150 RPM motor 2 HP and smaller

4280 4x3x11.5,  with 1750 RPM motor 5 HP and smaller

4280 4x3x11.5,  with 3500 RPM motor 7-1/2 HP and smaller

Shipping rate for continental USA



  • Model: 4280S-11-1/2
  • Manufactured by: Armstrong
  • UPC:

Manufacturer Info

About Us

Welcome to Shortys Pumps, a division of HVAC Supplies. We are located on the South West side of Indianapolis, IN. Our purpose is to provide Original Equipment Manufacturer parts for the repair and maintenance upkeep of furnaces, air conditioners, ventilation systems and pumps to the general public as well as contractors and commercial building maintenance staff.

Give us a call with the information from your equipment nameplate and we will do our best to help you locate the right paty. We can be reached at our local phone number 317-821-8770, Toll Free 877-821-8770 or by fax at 317-821-8772. Our business hours are 8-5 EST M-F. Prior to making repairs please check your manufacturers instructions and follow all safety precautions. Improper repairs can lead to equipment damage or personal injury or death. If you are unsure of your ability please call a professional to service your equipment.




Company Name

Shortys Pumps, division of Shortys HVAC Supplies


7720 S Mooresville RD
West Newton, IN
USA 46183

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Shortys Pumps, division of Shortys HVAC Supplies 2023