Why Rebuild Instead of Replace?
NAPCO repair kits let you restore a worn rotary gear pump to factory-new performance at a fraction of the cost of a full replacement. A typical rebuild costs 30–50% less than purchasing a new pump and can be completed on-site in 2–5 hours using standard hand tools — no need to disconnect piping, re-align the drive, or wait weeks for a new unit to ship.
Every component in a NAPCO kit is manufactured to the same tolerances as the parts in a new pump. When installed correctly, a rebuilt pump delivers the same flow rates, pressure capability, and seal integrity as the day it was first commissioned.
Choose Your Kit
Match your pump model to the corresponding repair kit. The first digit indicates port size (200 = 2-inch, 300 = 3-inch) and the suffix indicates material (C = ductile iron, S = stainless steel).
2-Inch Pump Kits (PK200 Series)
PK200C — Ductile Iron
For PA200C pumps. Includes PA250C/PA251C ductile iron gears, PM038 bearings, PM036/PM037 mechanical seals, and gaskets.
Best for: petroleum, asphalt, lubricants, waste oil, general industrial fluids
View kit details →PK200S — Stainless Steel
For PA200S pumps. Includes PA250S/PA251S stainless steel gears, PM038 bearings, PM036/PM037 mechanical seals, and gaskets.
Best for: chemicals, solvents, food-grade fluids, corrosive liquids
View kit details →3-Inch Pump Kits (PK300 Series)
PK300C — Ductile Iron
For PA300C pumps. Includes PA350C/PA351C ductile iron gears, bearings, mechanical seals, and gaskets. Kit weight approximately 34 lb.
Best for: high-volume fuel transfer, asphalt, heavy industrial fluids
View kit details →PK300S — Stainless Steel
For PA300S pumps. Includes PA350S/PA351S stainless steel gears, bearings, mechanical seals, and gaskets.
Best for: chemical processing, food & beverage, pharmaceutical applications
View kit details →What's Inside Every Kit
Drive & Idler Gears
Precision-machined matched gear sets — ductile iron or stainless steel
Front & Rear Bearings
Carbon graphite bearings (PM038) rated for continuous operation up to 100 PSI
Mechanical Seals
PM036 and PM037 seals that prevent leakage at the drive shaft entry point
Gaskets & Hardware
All gaskets and fasteners needed for a complete, sealed reassembly
Ductile Iron vs. Stainless Steel
| Feature | Ductile Iron (C) | Stainless Steel (S) |
|---|---|---|
| Corrosion Resistance | Moderate — suited for petroleum-based and non-corrosive fluids | High — resists acids, solvents, and corrosive chemicals |
| Typical Applications | Fuel transfer, lubricants, asphalt, waste oil, adhesives | Chemical processing, food & beverage, pharmaceuticals, solvents |
| Temperature Range | Standard industrial temperatures | Wider range including hot chemical processes |
| Cost | Lower cost option | Premium — justified when corrosion resistance is critical |
Not sure which material is right for your application? See our Stainless Steel vs. Ductile Iron guide for a detailed comparison.
When to Rebuild Your Pump
Gear pumps are designed for long service life, but internal wear is inevitable — especially in abrasive or high-viscosity applications. Common signs that a rebuild is needed include declining flow rate at normal operating speed, increased noise or vibration, visible leakage at the shaft seal, and higher-than-normal power draw from the motor.
For a detailed checklist of wear indicators, read our guide: 5 Signs Your Gear Pump Needs a Rebuild.
Related Resources
Pump Identification Guide
Identify your pump model, material, and port size from the nameplate
Maintenance & Service
Preventive maintenance schedules and best practices for rotary gear pumps
Installation Guide
Proper installation procedures to maximize pump life after a rebuild
Field Maintenance Guide
Step-by-step field maintenance procedures for rotary gear pump systems
Need a Repair Kit?
Contact NAPCO directly for pricing, availability, and technical support. Standard lead time is 6–8 weeks.
Request a Quote