Graco 166058 Piston Seal
$118.50
In Stock
Restore pressure and stop bypass on select Bulldog 5:1 rubber-packed pumps with this piston packing.
- Part No.: 166058 (Hycar piston seal)
- Fits: Bulldog 5:1 models 206418, 207321
- Role: Seals the piston for consistent output
- Tip: Verify against your pump’s parts list before ordering
Quantity
Genuine OEM Part
Fast Shipping (Order by 1 PM CST)
Easy Returns
Seal Function & Fitment Overview
Confirmed models that specify this piston seal in their parts list:
- Graco Bulldog 5:1 Pump – Model 206418 (Rubber-Packed)
- Graco Bulldog 5:1 Pump – Model 207321 (Rubber-Packed)
Key Details
| Part Number | 166058 |
|---|---|
| Item Name (Graco) | Seal, Piston (PACKING, Hycar) |
| Material Family | Hycar® (nitrile rubber) |
| Pump Family / Type | Bulldog 5:1 Ratio – Rubber-Packed pumps |
| Also Supplied In | Repair Kit 206931 (per Graco parts list) |
When to Replace
- Loss of pressure or pulsation despite normal settings
- Visible wear/flattening on old packing during service
- Frequent leakage past the piston after rebuilds
Frequently Asked Questions
Open your pump’s Graco parts manual and look for the piston/packing section. If the list shows part 166058, you’re good. If it shows a different packing (e.g., 166057 for PTFE-packed variants), order that number instead.
This listing is for the piston seal itself. Related wear parts (glands, seats, V-packings) are separate unless you purchase the full repair kit referenced in the parts list.
Clean all mating surfaces, lubricate as specified by Graco, and orient the packing correctly. After reassembly, cycle at low pressure to seat the seal and check for leaks.
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