Graco 15A043 Diaphragm Shaft – Detailed Description
The Graco 15A043 Diaphragm Shaft is a precision-engineered OEM component designed for seamless integration into Graco diaphragm pumps. Built to strict factory tolerances, this shaft plays a critical role in sustaining the correct motion, alignment, and longevity of the pump’s internal diaphragm system.
Why Choose the 15A043 Diaphragm Shaft?
- Factory‑spec OEM part ensures reliable, long-term performance
- Robust construction resists wear even under high-duty cycling
- Maintains precise diaphragm alignment to avoid leaks and uneven wear
- Direct replacement — designed for quick installation in compatible pump assemblies
- Critical for restoring optimal fluid delivery and consistent pump cycles
Typical Applications
- Industrial diaphragm pumping systems
- Pumps used in fluid transfer, chemical handling, or high‑pressure spray applications
- Graco diaphragm pumps requiring mid‑service part replacement or rebuilding
Installation & Service Considerations
When replacing the diaphragm shaft, it’s strongly recommended to inspect the rest of the fluid section — including the diaphragm, O‑rings, seals, and piston — and replace any worn or damaged components to maximize reliability and performance.
- Disassemble the pump carefully to avoid damaging the diaphragm.
- Clean internal surfaces to remove any grit or residue that may accelerate wear.
- Lubricate shaft lightly with manufacturer-recommended lubricant before reassembly.
- Torque any fasteners evenly, following Graco’s specified torque values.
- After reassembly, run the pump at low pressure briefly to check for proper operation before returning to full duty.
Indicators That Shaft Replacement Is Needed
- Excessive vibration or noise during pump cycles
- Diaphragm misalignment, flutter, or wear
- Fluid leaks that trace back to internal diaphragm seals
- Noticeable scoring, corrosion, or pitting on the shaft once exposed
- Decline in pump performance or pressure stability
Technical Specifications
| Parameter |
Specification |
| Part Number |
15A043 |
| Function |
Diaphragm Shaft in Graco Pumps |
| Material |
High‑strength alloy / hardened steel (factory‑grade) |
| Compatibility |
Graco diaphragm pump assemblies where 15A043 is specified |
| Duty Cycle |
Industrial‑grade; designed for frequent or continuous cycling |
Benefits of Using OEM Graco Shaft
Using an OEM part such as the 15A043 diaphragm shaft ensures that you preserve the original engineering design of the Graco pump. This leads to:
- Precise, factory‑intended motion and alignment
- Reduced likelihood of premature wear or internal damage
- Reliable sealing and less risk of leaks or misfires
- Maintained manufacturing warranty and part traceability
- Longer pump life and fewer rebuilds over time
Frequently Asked Questions
It transmits motion from the drive mechanism to the diaphragm, ensuring accurate and stable cycling within the fluid chamber.
It’s not recommended. Even small surface imperfections or micro-scratches on the shaft can shorten diaphragm life and compromise sealing.
Yes — it is only compatible with pump assemblies that list part number 15A043 in the official Graco parts breakdown.
Not always. While a worn shaft can contribute to leaks, it’s best to inspect and replace the diaphragm, O‑rings, and seals at the same time for a full rebuild.
