The Castair Replacement Pump Motor Kit MKD3-4 is a complete drive assembly replacement kit for Cast Air compressor pump and motor configurations. When a pump or motor reaches end of life, or when a compressor needs a full drive-end rebuild, this kit provides the components needed to restore the unit to operating condition without replacing the entire compressor. It's the economically sensible repair path for a compressor where the tank, frame, and supporting components are still serviceable but the pump and motor have failed.
Who Needs This Kit
Shops and facilities that own Cast Air piston compressors and want to repair rather than replace when the pump or motor fails. A replacement compressor can cost several times what a pump and motor kit costs — and if your existing tank and control system are in good condition, replacing only the drive components is the right repair strategy. This kit is also for service technicians who work on Cast Air equipment and need to restore units to factory operating condition.
Key Features
- Complete Replacement Kit: Includes the pump and motor components needed for a drive-end rebuild
- Cast Air OEM Parts: Matched components for compatible Cast Air compressor models in the MKD3-4 application range
- Restore-to-Service: Returns the compressor to operating condition without requiring a full unit replacement
- Correct Matching: Pump and motor components in the kit are matched to work together — no compatibility guesswork
Technical Specifications
- Part Number: MKD3-4
- Kit Type: Replacement Pump Motor Kit
- Category: Major Components / Pumps
- Manufacturer: Cast Air
Note: Manufacturer's product page was unavailable at time of writing. Specific horsepower range, pump displacement, motor specs, and kit contents were not confirmed. Price was not listed in the database. Contact us for current pricing, availability, and to confirm this kit fits your specific Cast Air compressor model.
When to Use a Pump Motor Kit Instead of Buying a New Compressor
- Tank, control panel, air distribution, and frame are all serviceable — only the drive end has failed
- The failed compressor is in a fixed installation where swapping a full unit would require significant downtime or infrastructure work
- Repair cost is significantly less than replacement — which is often the case with pump/motor kits on quality compressors
- You need to maintain the same footprint and connections in the installation
Why Buy From OEM Diagnostic Tools?
We carry Cast Air replacement pumps, motor kits, and major components for their compressor line. We've been supplying shops and industrial buyers with compressor parts since 2016. When you're looking at a pump or motor failure, the first question is always whether it makes more sense to repair or replace — we can help you work through that decision and identify the right parts. Call for current pricing and availability.
Call 866-217-0063 for quick answers and help!
