DigPig Silencer Nozzle Rebuild: Refresh Kit, Seat or Cover Upgrade?
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The DigPig Silencer is built so you never have to throw it away. Every part is replaceable, and DigPig sells the parts one at a time, so you can fix only what's worn instead of buying a full kit or a new nozzle. The trick is knowing which part you need. This guide covers how to tell which Silencer you have, what each rebuild part fixes, and the refresh kit procedure step by step.
Refresh kit, seat or cover: the short answer
- Stream slows, stops spinning or loses flow (and a clean filter coin didn't fix it): refresh kit.
- Seat is cracked or chipped, but the rotor still spins clean: replacement seat.
- Cover nose is worn or gouged, or you're getting spray back: standard cover or HD cover.
- Older Silencer with no tool grooves inside the body: Cover Up-Grade first.
- Leaking at the inlet: O-ring kit or a new ORB fitting.
- Cover working loose: spiral ring.
First, check which Silencer you have
Look inside the stainless steel body, in the threads where the cover screws on. Current Silencers have three tool grooves there. The SEAT-Cover Tool locks into those grooves to install the seat and to wrench the cover on and off.
- Three grooves: you can use the SEAT-Cover Tool and fit any current cover, seat or refresh kit.
- No grooves: this is an older Silencer. The tool won't fit it. The Cover Up-Grade brings it up to the current design with a standard Hi-Vis cover, a new grooved body and a spiral ring. The seat is sold separately.
While you have it in your hand, note the size number and the serial number etched on the nozzle. Kits are sized by nozzle number, and DigPig tracks every nozzle by serial number.
Silencer rebuild parts and what each one fixes
On a phone, swipe the table sideways to see every column.
| Part | What it fixes | Notes | Price |
|---|---|---|---|
| Refresh kit | Worn rotor, seat, O-rings and inlet orifice bolt | Full rotor system, seat and all O-rings. Order by nozzle size | $228 |
| Replacement seat | Cracked or damaged seat | Tungsten carbide; includes its O-ring | $51 |
| O-ring kit | Leaks, worn seals | All 5 O-rings; fits every Silencer size | $19 |
| Standard cover | Worn or cracked cover | The Hi-Vis cone-taper cover that ships on the nozzle | $108 |
| HD cover | Fast cover wear, spray back | 1/4" thicker nose; full cylindrical body cuts spray back | $122 |
| Cover Up-Grade | Older Silencers without tool grooves | Standard cover, grooved body and spiral ring; seat sold separately | $150 |
| SEAT-Cover Tool | Seat removal and install, cover wrenching | 3-in-1 tool; grooved Silencers only | $81 |
| Spiral ring | Cover loosening | Stainless ring that holds the body in the cover | $10 |
| Filter coin | Debris reaching the rotor | 4-port stainless coin with a micro-screen; single or 5-pack | $23 |
| ORB fitting | Damaged inlet fitting | Includes its O-ring | $22 |
HydroVac Supply prices as of October 2026. The Silencer nozzle itself is $550.
A refresh kit costs about 40% of a new Silencer, and a seat or an O-ring kit costs a fraction of that. That's the case for buying parts as you need them.
When the Silencer needs a refresh kit
The refresh kit replaces everything that wears from water flow: the full rotor system, the tungsten carbide seat, all the O-rings and the internal inlet orifice bolt. Reach for one when:
- The stream stops rotating, or stops after running a while.
- Flow or pressure drops and cleaning the filter coin doesn't bring it back.
- You see scratching or gouging inside the inlet.
- You want to change the nozzle's flow. Haaker, a DigPig dealer, notes the Silencer's GPM can be changed with purchased kits, since the rotor and orifice bolt set the size.
Check the cheap things first. A plugged filter coin, low supply pressure or a clogged rotor causes the same symptoms as worn parts.
When a seat alone is enough
The seat is the tungsten carbide part the rotor spins against, up in the tip of the body. If the rotor and O-rings look good but the seat is cracked or chipped, a replacement seat with its O-ring fixes it. You'll need the SEAT-Cover Tool to pop the old seat out and set the new one.
Standard cover vs HD cover
The cover takes the beating at the bottom of the hole. The standard cover is the Hi-Vis yellow, cone-tapered cover the Silencer ships with. The HD cover is an upgrade with a nose that's 1/4" thicker to extend nozzle life and a full cylindrical body that cuts spray back.
Run the HD cover if you wear through covers in rocky or abrasive ground, or if spray back is a problem. For the most splash protection, DigPig recommends its Armour Guard, a magnetic splash guard. Both covers need the SEAT-Cover Tool to install.
How to rebuild a DigPig Silencer with a refresh kit
These steps follow DigPig's Silencer manual. You need the refresh kit for your size, the SEAT-Cover Tool, an adjustable wrench, a long 1/2" socket and a filter strap wrench (or a firm grip) for the cover.
- Shut down. Turn the pump off and disconnect the hose before you touch the nozzle.
- Separate the inlet. Hold the yellow cover with a filter strap or a firm grip, put the adjustable wrench on the inlet and turn it counterclockwise until it separates from the housing and cover.
- Pull the rotor and set the old one aside.
- Remove the seat. Press the SEAT-Cover Tool gently into the tip until the seat pops out.
- Install the new seat. Set it on the pointed end of the tool with the seat's rounded pocket facing the red part of the tool. Line up the tool's three guides with the guides in the housing threads and push gently until you feel or hear a soft click. The seat should sit flush.
- Replace the inlet orifice bolt. Use the long 1/2" socket and the adjustable wrench to unscrew the internal inlet orifice bolt. Install the new one and tighten it firmly.
- Fit the new O-rings from the kit, and check the inlet O-rings for nicks before reassembly.
- Reassemble. With the inlet upright, drop in the new rotor roller side down. Push the cover and housing down firmly until it clicks, screw it clockwise, then tighten with the wrench while holding the cover with the strap.
- Check the filter coin and ORB fitting. Make sure the coin is in place and the ORB fitting is tight.
- Reinstall and test. Flush the hose to clear debris, put thread tape on the lance threads and tighten the nozzle onto the lance. The ORB fitting seals with an O-ring, so it doesn't need tape or thread dope. Point the nozzle at the ground and start the pump.
Silencer troubleshooting
| Problem | Check and fix |
|---|---|
| Stream won't rotate or stops | Confirm at least 1,000 PSI at the nozzle and an adequate water supply. Clean the filter coin screen, clear the rotor, inspect the inlet O-rings, and check the carbide tip and seat. Refresh kit if parts are worn. |
| No flow or low flow | Clean the filter coin. If flow is still short for your pump, go to a larger nozzle size. |
| Spray back | Lower the pressure and hold the nozzle closer to the ground. Upgrade to the HD cover or add the Armour Guard. |
| Scratching or gouging inside the inlet | Clean out internal debris, replace a damaged filter coin, and check the seat, tip and rotor. |
| Leak at the inlet | Replace the O-rings or the ORB fitting. |
| Cover loosens while digging | Replace the spiral ring. Without it, the cover vibrates off the housing. |
Based on the troubleshooting section of DigPig's Silencer manual.
Keep your Silencer running longer
- Clean the filter coin every day. It's the only thing between your water tank and the rotor. Keep a 5-pack of coins on the truck.
- Run clean, filtered water only. DigPig's manual says no chemicals, and its warranty excludes damage from poor water quality.
- Stay inside the ratings. DigPig's current manual lists 1,000 PSI minimum, 2,500 PSI recommended and 3,200 PSI maximum inlet pressure, with water up to 205°F. Older spec sheets list a 4,200 PSI maximum, so go by the current manual.
- Keep it from freezing. Freeze damage isn't covered by DigPig's 90-day warranty.
- Use genuine DigPig parts. The warranty excludes unauthorized parts.
- Dig safely. DigPig's manual recommends a 1,500 PSI working pressure and at least 2 feet from any utility. Keep the wand moving, and point the nozzle down at startup.
Silencer flow by size
Refresh kits are sold by nozzle size, so order the size stamped on your nozzle unless you mean to change flow. DigPig's flow chart:
On a phone, swipe the table sideways to see every column.
| Nozzle size | 1,500 PSI | 2,000 PSI | 2,500 PSI | 3,000 PSI |
|---|---|---|---|---|
| #4 | 2.4 | 2.8 | 3.2 | 3.5 |
| #6 | 3.7 | 4.2 | 4.7 | 5.2 |
| #8 | 4.9 | 5.7 | 6.3 | 6.9 |
| #9 | 5.5 | 6.4 | 7.1 | 7.8 |
| #10 | 6.1 | 7.1 | 7.9 | 8.7 |
| #12 | 7.3 | 8.5 | 9.5 | 10.4 |
GPM from DigPig's Silencer nozzle selection chart. We stock sizes #4, #6, #8, #10 and #12.
DigPig Silencer rebuild FAQ
What's in a DigPig Silencer refresh kit?
The full rotor system, a new tungsten carbide seat, all the O-rings and the internal inlet orifice bolt. Order the kit that matches your nozzle size.
Do I need the SEAT-Cover Tool?
Yes, to remove and install the seat and to wrench covers on and off. It only fits Silencers with three tool grooves inside the body. Older Silencers need the Cover Up-Grade first.
How do I know if I have an old Silencer?
Look inside the body where the cover threads on. No tool grooves means it's an older Silencer and needs the Cover Up-Grade to use current covers and the tool.
Should I buy the HD cover?
If you wear through covers or fight spray back, yes. The HD cover's nose is 1/4" thicker and its cylindrical body reduces spray back, for $14 more than the standard cover.
Is a refresh kit cheaper than a new Silencer?
Yes. At HydroVac Supply, a refresh kit is $228 and a new Silencer is $550, so a rebuild costs about 40% of a new nozzle.
Why does my Silencer cover keep coming loose?
The spiral ring holds the body in the cover. If it's missing or worn, the cover vibrates off the housing. A replacement spiral ring is $10.
Need help with a rebuild?
Call 402-237-1914 or email info@hydrovac-supply.com, Monday to Friday, 7 AM to 4 PM. Tell us your Silencer's size and whether it has tool grooves, and we'll match the parts. All Silencer parts are in Nozzle Rebuild Kits and on our DigPig page. Comparing the Silencer to other nozzles? See our best hydrovac nozzle guide.