Overview & Fitment Guide for Graco 103255 Packing O-Ring
Compatible Machines
- Graco PrecisionMix II plural-component systems (parts list calls out 103255 O-Ring)
- Selected Graco engine-driven / electric sprayers with pump or cylinder interfaces that specify 103255 in the manual
- Other Graco pump/cylinder assemblies where the service parts list references 103255 – O-Ring, Buna-N
What is it?
The Graco 103255 Packing O-Ring is a genuine sealing element used to prevent leaks at critical threaded or cylindrical interfaces within Graco pumps and plural-component systems. Commonly listed as an O-Ring, Buna-N, it restores sealing performance during routine service or rebuilds.
Key Specifications
| Part Number | 103255 |
| Item Type | Packing O-Ring (seal) |
| Material | Buna-N (NBR) elastomer (verify chemical compatibility with your coating/solvent) |
| Typical Location | Threaded cylinder / housing interfaces in Graco pumps & plural-component systems |
| Function | Prevents fluid bypass and leakage under pressure; maintains prime and system performance |
| Interchange / Cross-Ref | Use only where the equipment parts list explicitly specifies 103255 |
Use & Installation Notes
- Depressurize and follow Graco safety procedures before service.
- Clean mating surfaces; lightly lubricate the O-ring if recommended by your manual.
- Seat evenly and torque housings to spec to avoid pinching or extrusion.
- Replace if flattened, cracked, swollen, or if leakage is observed after service.
Frequently Asked Questions
It fits models whose official Graco parts list specifies 103255. Check your unit’s manual by model and serial for confirmation.
Typically Buna-N (NBR). Verify fluid compatibility for your paint, solvent, or catalyst before installation.
Use the genuine Graco part where specified. Substitutions must match size, durometer, and material—and may affect performance or warranty.
Persistent leakage at the cylinder/housing, loss of prime, or visible damage (flattening, cracking, swelling) are common indicators.
Some service kits may include this O-ring along with other seals. Check the kit’s BOM or your machine’s service manual for exact contents.
