The Max-Flo is one of the most celebrated regulators available. It is another of the few regulators that can deal with both compressed air and C02 very proficiently. There are high pressure and low pressure versions but most found are of the low pressure type that have a range between 0 - 300psi. Most that you see will be attached to any of the various Smart Parts markers. Not in the least known as a low maintenance regulator but will require less attention when using compressed air over C02. I will instruct you how to disassemble and clean the 3000 and first version of the vertical Max-Flo in this article.

The Max-Flo can be found in many configurations. The 4500 horizontal comes with an attached nitro bottle, on/off and has a dovetail 'V' groove mount that is normally attached to the bottom of a grip frame. The 3000 horizontal is of a female type that has an integral air supply adapter built into the body and has a dovetail 'V' groove mount as well. The initial vertical version is of a male type that screws into a vertical ASA. The newer vertical version is of the same male configuration and has been slimmed down quite a bit from the initial version but mounts in the same manner. All come with an attached macro line fitting and the horizontal versions come with a pressure gauge attached as well.

Disassembly

The Max-Flo has a few more parts than most other regulators but if you lay the parts on a towel or similar in the order that you removed them in, you should have no problem keeping track of which order to put them back in. You can download any of the Smart Parts manuals from their website as well.

The top portion of the photograph above shows the spring cap end components exploded in order with the horizontal Max-Flo body. The bottom half shows the poppet components end exploded in order with the vertical Max-Flo body. All internal components of both versions are exactly the same and are placed in the same order as well. The external differences are of course the bodies themselves and at the poppet guide end, the horizontal has a retaining nut and the vertical version has a threaded end with adjustment nut that can be screwed into a vertical adapter.

• For disassembly we'll start at the spring cap end. Unlock the spring cap locking screw with a 7/64" allen wrench if you have it torqued down, then unscrew the spring cap from the regulator body.
• The gold colored filter, plastic bumper, pressure spring, spring guide and guide pin will come out when the cap is removed. When reinstalling these components remember that the rougher side of the filter faces the plastic bumper and the rounded end of the spring guide pin faces the pressure piston. The flat end of the spring guide pin is inserted in the spring guide.
• Remove the brass pressure piston from the end of the reg body. If you cannot remove it with your fingers, use a pair of needle nose pliers and be careful not to mar the surface because brass is a very soft metal. There are high and low pressure versions of the pressure piston. The low pressure version has 2 grooves cut into it and one of them has an o-ring in one of the grooves. The high pressure version has 1 groove only that has an o-ring in the groove.
• We'll now remove the components from the other end of the regulator. If it's the horizontal, remove the end retaining nut with a 3/8" allen wrench. If it's the vertical first loosen the 2 allen screws in the side of the body with a 3/32" allen wrench then unscrew the threaded end with adjustment screw from the body. Now you can remove the poppet guide, spring retainer and filter assembly, poppet and spring, seat cap & base with encapsulated o-ring assembly then an o-ring. You'll most likely need some sort of pick to remove the o-ring because it is somewhat embedded into the body. Just pick it out from the outside diameter of the o-ring and be careful not to deform it in any way or you may create a leak.

The vertical body has a micro line fitting and 3 plugs installed in it. You can locate the micro line fitting in either of the top receptacles. A pressure gauge can be added to the alternate receptacle. The lower 2 receptacles are for a pressure relief valve (PRV). The PRV is provided to release any excess pressure to avoid blowing the sensitive pneumatic solenoid that is provided with Smart Parts markers. If your Max-Flo is installed on a marker that doesn't have a pneumatic solenoid, the PRV isn't needed. The PRV can be installed in the VA rather than the reg itself if there is a pneumatic solenoid. Some people choose to put the PRV in the regulator and a low pressure regulator(LPR) in the VA if they don't want the LPR in the end cap on such markers as the Impulse.

You now have all of the necessary components removed and it's time to clean all of the old grease from the parts and the internal body areas.

There are some internal assemblies such as the poppet guide which has 2 o-rings on it, pressure piston has 2 o-rings, spring retainer & screen assembly and seat cap & base with o-ring assembly that aren't necessary to disassemble to clean them. I would suggest doing it if you can anyways because you may as well clean the Max-Flo thoroughly while having it apart........your choice.

• Using an old cotton rag or paper toweling, remove all the old grease and residue from the internal components and the inside of the regulator body. I use 50 weight 100% silicone RC car shock lube on the internal components of my Impulse but use Dow33 only when lubricating the Max-Flo since there are no continual moving parts inside the regulator. The heavy consistency of Dow33 will extend the lubricating properties to last a lot longer than any other type of lubrication as well. When using the Dow33, a little goes a long way. You need not gob it on and yet you don't want to put it on too thin. Just put enough to where you can see the pink color of the Dow33 vaguely but not so much that there is a relevant excess.
• Lubricate all of the internal components and the internal areas of the body where the components normally are with your finger. Don't forget the external threads where the spring cap threads mesh and the o-ring on the threaded end with adjusting nut for the vertical regulator. It's not necessary to lubricate the filter element and low pressure spring.

Now that all of the components and internal areas of the body are cleaned and lubricated, reinstall all components in the reverse order that you removed them in. Take your time installing the poppet end components and don't force anything back in place. Torque the retaining nut down well for the horizontal version and torque the 2 set screws of the body down well on the vertical version. You don't want your reg coming apart in the middle of a game.

You may consider lubricating your Max-Flo 2 or 3 times a year depending on how much you use it. As I stated earlier, if using C02 you may want to clean and lube it a bit more often as C02 tends to cause more wear and tear on o-rings and such. I normally go by when the spring cap gets a bit tight to turn as a sign that the reg needs to be cleaned and lubed.

It may be a bit difficult the first time you try cleaning the Max-Flo but after a couple of attempts you'll find that it's not that much of a task at all.

Technical Information