Shocker SFT Solenoid > Tech index > Shocker SFT > Parts of a Shocker > Solenoid

The solenoid of a paintball marker is the physical connection between the electronics that fire the marker, and the pneumatics that do the actual firing operation. The solenoid is an electromagnet-based valve that is used to switch airflow within the marker, simultaneously pressurizing and depressurizing different parts to actuate the valve system. Every electronic marker uses a solenoid, although there are many differences in some of the valves used in other applications.
The solenoid in the Shocker is located attached to the underside of the body, within the grip frame.
Solenoid Solenoid

Solenoid Operation:
The purpose of the solenoid is to take in pressurized air and output it into one of two possible ports. This makes the solenoid in the Shocker a four-way valve, meaning it has two inputs and two outputs. The output air is shunted into the solenoid inserts, where it leads to the bolt sleeve and forces the bolt in one direction (either forward or back).
To recap the Shocker's firing cycle, while the marker rests idle, pressure is forced into the front of the bolt sleeve to hold the bolt open. This air is directed there through the solenoid valve. When the trigger is pulled and the solenoid energized, the solenoid's valve switches positions and the air holding the bolt open is vented, while at the same time pressure is delivered to the rear of the bolt, which closes it forward. Once it reaches the full forward position, air pressure is released and the paintball is fired down the barrel. After the dwell time expires, the solenoid will switch back to the idle position by venting the air holding the bolt closed and repressurizing the other output (to open the bolt). After this time, the marker is ready to fire once more.
Tech If you wish to learn more about how the solenoid works, please refer to the How solenoids work link in the Related Links section. Detailed information and diagrams can be found there.

Solenoid Types:
Currently, there are two directly compatible solenoids with the Shocker and Nerve. The original solenoid was a Parker K4H03, which was used from 2003-2005. In early 2005 Humphrey released a new solenoid called the CRCB-0045W which was specifically designed to function in a Shocker or Nerve. Smart Parts used both the Parker and Humphrey solenoids until late 2006, when they went back to Parker solenoids exclusively. Meaning, they no longer use the Humphrey CRCB valves.

There isn't one overall "better" solenoid; they both have their own advantages and disadvantages. Acordingly, there's no reason to buy the other type of solenoid if your current one works. The solenoid doesn't play that important a role to the point where it would make any noticeable difference.
Technically speaking, the Humphrey solenoids offer quicker internal venting and can handle much higher pressures without any problems. They're also manufacturered much better and as a result tend to be more reliable over time. Parker solenoids are able to cycle faster due to a more simple design. The Humphrey solenoids offer a removeable upper circuit board to help compat the problem of Parker solenoid coil damage. Parker solenois require you to desolder the upper board in order to remove it (see the below section Connection).

It is true that the Parker K4H01 solenoids from the Impulse and pre-03 Shocker will functionally work in a 2003+ Shocker. However, the circuit board won't attach to the top of one of these solenoids (they're designed to attach with wires leading to the board, not the board itself). It is true that they can be modified to fit, however this isn't a modifiction I suggest you perform unless you have the right equipment. The solenoid terminals are very fragile and easy to destroy in the process.

Solenoid/Upper Board Connection: Warning
The relation of the solenoids with the upper board is simple in this regard. The upper board is removable with the newer Humphrey solenoids, but NOT removable with the older Parkers. With the Parker solenoids, the two coil terminals stick up out of the coil housing, and are soldered directly to the board. The board therefore cannot be removed unless it is desoldered from the solenoid terminals. I personally do not recommend doing this for any reason, unless you are absolutely forced to do so. I recommend this soldering task only for advanced technicians, since desoldering the solenoid is a very delicate operation and the coil terminals are extremely fragile.

Solenoid Manifold:
The solenoid is screwed onto the body of the Shocker at the spool housing end; this is the end where airflow is exchanged between the Shocker and the solenoid. Located between the solenoid and the Shocker body is a metal plate known as the solenoid manifold, which supports and aligns the necessary seals that are required to maintain the air exchange between them. Specifically, the manifold houses six small o-rings, which are used to seal the input and outputs. This diagram shows the o-ring grooves and the o-rings that fit inside:
The manifold accepts the above sizes of metric o-rings to seal its o-ring grooves. Please note that the 1x3-mm o-rings are regular "circular" o-rings that simply are fitted into an ovular groove. When installed they will appear ovular, however they're just regular o-rings to begin with.
Warning The tapered side of the manifold faces toward the front of the marker. The marker will leak if installed backwards.
Warning Although the Nerve also uses a solenoid manifold, Shocker and Nerve manifolds are not interchangeable.
Warning Solenoid "body gaskets" from Impulses and pre-2003 Shockers will not work with a 2003+ Shocker solenoid.

Solenoid Manifold Mounting:
The solenoid manifold is secured onto the Shocker body using a pair of 4-40 x 1/4" button head screws, which accept a 1/16" allen wrench for removal. The solenoid itself is attached to the top of the manifold using a pair of specialty spacer screws, which will also accept a 1/16" allen for removal, however can't be purchased at a local store. The spacer screws have a tall head to help support the upper circuit board.
Solenoid Solenoid
Also please refer to the manual scan in the Related Links section, which has a nice exploded diagram of the manifold and its screws.

Older 2003 model Shockers used a different style of spacer screws, which are still occasionally seen today. These screws secured the solenoid down and were tightened using a 1/8" socket on top, then used a separate pair of lock screws that held the board down. These were replaced coming into 2004 since assembly was very difficult, and ever since then the spacer screws have been used.

Warning When reinstalling solenoid spacer screws, DO NOT overtighten them into the manifold. The threads are very fine and will happily strip themselves out if you torque the screws down as hard as you can. Overtightening screws in the marker is never a good idea, and will be extremely easy to cause damage in this case. A stripped solenoid manifold can only be repaired by replacement.
Many people simply prefer to leave the spool housing section of the solenoid attached to the manifold, and remove it only when absolutely necessary. Ideally, your solenoid manifold won't be able to strip itself out if you never actually screw the screws down into it (as in, if you never have the chance to strip the manifold out, it won't become stripped, thus solving the problem). For troubleshooting it may be necessary to remove the solenoid, but otherwise I tend to agree with this philosophy.
Warning Severe overpressurization to the marker can, in some cases, strip the solenoid manifold spacer screws as well. This would generally be pressures of 240-psi or higher. If you overpressurize your marker and it is now leaking, this is a probable cause (please refer to the Troubleshooting page for solenoid leak information).

Aftermarket Solenoid Manifolds:
These aftermarket manifolds are mainly to help guard against stripping problems, since they are made from stainless steel. This material can still be stripped, though it is a bit less likely (if you strip your stainless manifold, you really need to back off on the allen wrenches). Below is a list of the available aftermarket counterparts:
New Designz stainless manifold: NDZ has developed their own aftermarket manifold for the Shocker. This new manifold offers ball-rounded exchange grooves to help increase airflow and venting. Available for approx $30.

Evolve stainless manifold: Another stainless steel manifold. This one offers a bit of additional flow for the solenoid's exhaust vents, which helps to maximize cycling speeds. Costs $35 plus ship.

Smart Parts Air Vent manifold: Aftermarket manifold made from 7071-grade aluminum, available from Smart Parts. This manifold also offers additional flow, and can even be adjusted (however the use of such a feature is negligible). Costs $50 and is only available from SP Europe at the time of this writing.

The solenoid is a pneumatic valve that switches airflow within the marker, when energized by electricity from the circuit board.
Older markers came with Parker solenoids, newer ones come with Humphrey solenoids.
Parker solenoids are NOT removable from the circuit board. Humphrey solenoids are.
The solenoid manifold is a mounting plate between the solenoid and the body; it houses o-rings that seal the solenoid pressures.
The solenoid manifold is easily stripped by overtightening.

Related Links:
Shocker solenoid assembly manual scan
Shocker leak troubleshooting
Solenoid maintenance
How solenoids work
Upper circuit board