Graco 103557 Packing O-Ring
The Graco 103557 Packing O-Ring ensures a tight seal in spray gun assemblies, preventing leaks and maintaining consistent pressure performance.
- OEM replacement part for Model D Spray Gun
- Also fits ProMix Auto and PRO4000 series assemblies
- Maintains proper fluid and air sealing integrity
- Durable material for extended service life
OEM Seal for Graco D-Gun & Selected Systems — Graco 103557 Packing O-Ring
Compatible Machines / Assemblies
- Graco Model D Spray Gun (mixing chamber variants D-46, D-55, D-62, D-70, D-78)
- Graco PRO4000 (legacy spray gun models listing 103-557 O-ring)
- Graco ProMix Auto system assemblies that specify 103557 in their parts list
Product Overview
The Graco 103557 Packing O-Ring is a genuine OEM sealing ring used in Graco spray equipment to maintain pressure integrity and prevent fluid or air leaks at critical interfaces. It’s commonly installed in the Model D spray gun and appears in select ProMix Auto assemblies and certain legacy PRO4000 guns where specified.
- Function: Seals dynamic/static joints in gun or manifold sub-assemblies to prevent bypass and pressure loss.
- Performance: Supports consistent atomization by preserving stable system pressure.
- Service Use: Replace during rebuilds or when leakage, pressure drop, or wear is observed.
Key Specifications
| OEM Part Number | 103557 (also referenced as 103-557 in older manuals) |
|---|---|
| Part Type | Packing O-Ring (seal) |
| Primary Application | Model D Spray Gun; appears in specified ProMix Auto assemblies; certain PRO4000 guns (per manual). |
| Installation Notes | Lubricate lightly (per manual), seat without twisting, and confirm in-groove fit before reassembly. |
| When to Replace | On rebuilds, evidence of leakage, loss of pressure, or visible damage/flattening. |
Manual Cross-References
- Model D Spray Gun parts list shows AS 103557 — O-ring within the assembly.
- Legacy PRO4000 documentation lists 103-557 — O-RING (Viton) in the gun assembly.
- ProMix Auto service/parts materials reference PACKING, O-RING 103557 in select modules.
Maintenance & Fit Guidance
- Confirm your exact model and revision; Graco manuals occasionally list older part formatting (103-557).
- Replace in pairs/sets if your assembly uses multiple seals in series to maintain balanced compression.
- Use genuine Graco 103557 to ensure proper durometer and dimensional tolerance.
Frequently Asked Questions
No reviews yet. Be the first to review this product!