Nerve infrequent maintenance ZDSPB.com > Tech index > SP Nerve > Adjusting and maintaining > Infrequent maintenance
This page compromises maintenance processes that don't need to be performed very often. Details vary depending on the part.

These are the things you'll need for the tasks listed on this page: dental picks, assorted allen wrenches (0.05", 1/8", 1/16", 5/64", 3/16", 5/32", 3/8"), 7/8" wrench (x2, if possible), 9/16" wrench, q-tips, Sleed lubricant (aka. Dow33, Shocker lube, Molykote 33).

Piston Maintenance:
Maintenance to the ram assembly is recommended every six or so months, or 20,000 shots, whichever comes first (this is only my recommendation). To perform this task you must remove the bolt assembly from the back and also the LPR assembly from the front. These are described on the Regular Maintenance page.
Piston maintenance requires the complete disassembly of the marker. You will need to remove the grip panels using a phillips-head screwdriver, remove the battery, and disconnect the wire harness from the vertical board. Now, separate the frame from the body using a 1/8" allen wrench for the front screw and a 5/32" wrench for the rear one. Set the frame aside.
Frame removal

The next step is to remove the Vision ribbon so you can access the valve. For this you must remove the detents (or at least the left one) using a 1/8" allen wrench. Insert a small 0.05" allen wrench into the hole in the eye cover, then unscrew the hidden screw underneath (it's angled 15º upwards). Once the screw disengages, you can remove the eye cover and pull the Vision ribbon out (you may need to push it away from the chamber by sticking a small allen wrench through the opposite detent hole). Removal of the eye ribbon is REQUIRED in order to take out the piston; do not attempt to proceed with this process without removing the eye ribbon.
Frame removal Vision section

Flip the body upside-down and use a 5/32" allen wrench to remove the valve lock screw from the underside of the body (right in front of the solenoid). Once the screw is out, you can push out the piston. For this I suggest you use a wooden dowel or similar non-metallic tool to push it from the front. Another method is to use the bolt to pull the hammer out the back of the body.
Piston removal Piston removal

The first step in piston disassembly is to use a pair of 3/16" allen wrenches to unscrew the hammer from the ram. Insert one into the head of the ram at the front, insert another into the back of the hammer, then unscrew the two apart. This may take some force to accomplish because they are loctited together.
Hammer removal

Once the hammer is disengaged, Remove the hammer bumper from the ram and set it aside with the hammer. Then use two 5/8" wrenches to unscrew the two sections of the piston from one-another. Again, loctite was used, so a lot of force may be necessary. Once the two sections are apart, set the front (valve) housing aside then pull the ram out from the rear (piston) section. There's a small bumper located around the hidden end of the ram, take note that it may or may not come out with the ram once removed.
Piston disassembly
If the bumper doesn't come out with the ram, look for it inside the piston. It will often be visible from both ends.
Piston bumper

The rest of this section is devoted to the proper reassembly of the piston. This is my "quick method" for maintenance and reassembly, which details how I service all Nerves.
Step 1: Start by cleaning off all the old grease from the piston housings, ram, and hammer. Use a q-tip to clean the inside of the piston sections.
Step 2: The next step is to apply a new coat of grease to the ram sail o-ring in the middle, as well as a coat on either side of it. This will serve to distribute grease to the two inner piston o-rings. Be very generous with the amount of grease you use on the ram here, it is unlikely you will actually overgrease the setup.
Ram grease
Step 3. Make sure the bumper is installed on the ram, then insert it (threaded end first) into the opening in the piston housing. Push it all the way down.
Piston reassembly
Step 4. Place a small amount of loctite on the threads of the piston housing, insert it back onto the ram, and screw the two together. Tighten them up but don't overexert yourself, since you will need to take it apart in the future.
Valve reassembly
Step 5. Install the close bumper onto the threaded end of the ram then apply a small amount of loctite to its threads. Screw the hammer onto the ram and use 3/16" allen wrenches to tighten it down.
Hammer reassembly
Step 6. Apply a new coat of grease to the five external o-rings on the piston.
Hammer reassembly
The piston is now ready for reassembly. Important note: If you scratched the outside of the housings using pliers during disassembly, you MUST grind down the scratches you left. If you fail to do this, you risk scratching the inside of the body bore and causing unwanted leaks (and buy a new body).

To reassemble the piston assembly into the body, start by dropping the piston into the rear of the Nerve body with the open hole in the valve housing facing up. The hole on the opposite side of the housing isn't open and faces down. Push the piston into the lower bore and watch through the valve lock screw hole for the point when the hole in the valve housing becomes visible. Once it's aligned, reinstall the valve lock screw using 5/32" allen wrench.
Additionally, take note when the piston housing o-rings pass through the milling in the rear of the body. If any o-rings get pinched you will need to remove the piston and replace them.
Piston reinstallation

Below are some demonstrational videos to show highlights from the above process. Be sure you read the above description first to make sure you're familiar with the overall goals.
Piston maintenance, high-res (44-MB)
Piston maintenance, medium-res (19-MB)
Piston maintenance, low-res (7-MB)

This concludes maintenance to the piston assembly.

SFT O-ring:
The SFT o-ring is located inside the Shocker body, right in front of the barrel. This o-ring seals against the bolt during firing.
SFT o-ring SFT o-ring SFT o-ring
The SFT o-ring can be the cause for paint breaking issues, especially during the winter. If necessary, remove the o-ring using a curved or bent dental pick, and replace with a clean, new 17/90 o-ring. If you chop a ball in the chamber then paint will most likely work it's way around the o-ring, in which case replacement is recommended.

To remove the SFT o-ring for replacement, you'll have to use a curved or angled dental pick. The one I use has a small crease right at the end, which makes it ideal for pulling o-rings from their grooves. Dig the end of the pick down into the o-ring groove (between the ring and the groove wall; don't just spear the o-ring with the pick..this won't work), then twist the pick around to get under the o-ring. This can be accomplished in front or behind the o-ring, depending on the shape of the pick. Once hte pick is under the o-ring it will be easy to remove it.
SFT o-ring SFT o-ring SFT o-ring

Solenoid Manifold:
The solenoid manifold involves six small o-rings to seal the solenoid's pressures. These o-rings don't require any maintenance and in most cases are best if left alone. Some solenoid leaks can be caused by the rings, in which case disassembly and replacement would be suggested (see the Troubleshooting Solenoid Leak page for details on this).
Removal of the solenoid also brings along the potential improper reassembly (overtightening) on the solenoid manifold spacer screws. To help avoid this issue, it's best to just leave the manifold alone unless otherwise necessary.

Below are some demonstrational videos showing removal and rebuilding of the solenoid manifold.
Solenoid manifold installation, high-res (13-MB)
Solenoid manifold installation, low-res (5-MB)

Solenoid Insert:
The solenoid insert also contains o-rings, however it doesn't require any maintenance of its own unless a problem has arisen. Refer to the Solenoid Inserts page for details on its removal and reinstallation.

O-ring Diagrams:
Firing assembly

Misc assemblies

Related Links:
· Breech section (SFT o-ring)
· Solenoid insert
· Troubleshooting Leaking/Shooting
· Pressure & dwell setting