Maintenance frequency:Max-Flo Inline systems require only occasinoal maintenance. The reg is deisgned to put out many weeks of service without issues. If you find your pressure dropping off, though, then it may be time to clean the system. Suggested interval for maintenance would be every 15,000-25,000 pressurized cycles, or 3-4 months.
These are the things you'll need to disassemble and clean your regulator: assorted allen wrenches, 3/8" allen wrench, Shocker lube, Q-tips, napkins/paper towel/cloth.
Regulator Disassembly:
The reg has two sections: the manifold and the regulator. The upper section (manifold) is where the tanks screws on; the lower section is the actual regulator part. It is required that you remove the regulator from its manifold to service it, and disconnecting your gasline from the reg will also make things easier (macroline works good). The tank doesn't have to be empty so long as the Smartvalve is in the off position, however if you will not be able to service the manifold's built-in Smartvalve while there is any psi left in the tank.
Either way, to separate the reg from the manifold, you have to remove the four screws on the bottom of the manifold clamp (piece that stretches around the bottom of the reg body). Once the screws are out, you can pull off the regulator and disconnect your gasline (again, this is not required, however it helps to make things easier).
The regulator itself is divided up into two main sections: the input stage and the output stage. The input stage contains the poppet assembly and is accessed through the back of the reg body; the output stage contains the adjustment spring and related components and is accessed via the adjustment cap in front. To begin with, unscrew the adjustment cap from the front of the regulator body, and let all the components of the output stage assembly fall out.
Also remove the brass piston from within the regulator body (you can use a small allen wrench or dental pick if needed).
Flip the regulator around and use your 3/8" allen wrench to remove the retaining nut on the rear end of the regulator body, then tip it up to let the input stage components fall out. Be aware that the outer base seal o-ring may have remained seated within the reg body. You can remove it if you wish, but be sure not to scratch this o-ring or else you will be forced to replace it...
Regulator Maintenance:
The task is to clean all the components of the input stage as well as the internal surfaces within the reg body. Also clean the grease from the piston and its o-ring, and also the hole in the reg body where it goes. There is also a small o-ring on top of the piston; clean this as well (a q-tip works well).
You can also disassemble the base seat. Located within is a small o-ring (inner base seal) that needs to be cleaned or replaced if necessary. The outer base seal o-ring must also be in perfect condition. These two rings and their opposing surfaces are the key to the regulator's consistency and will cause noticeable problems if not useable.
If your manifold leaks out the Max-Flo jewel in front, then remove the jewel and unscrew the small fitting located beneath. There is an o-ring around it, this is what needs to be replaced. You can grease this ring when you reinstall. However, if your jewel isn't leaking, then just leave this fitting alone.
Regulator Reassembly:
The regulator is specifically designed for the input stage to be installed before the output stage. Start by reassembling the input stage as per the following diagram, then drop it down into the rear of the reg body. Notice that the poppet fits into the angled end of the assembled base seat. Use no grease on any of the parts in the below diagram. Before you drop the input stage into the reg, be sure to drop the outer base seal o-ring down into it first.
Once the input stage is back into the reg, lightly re-grease the o-ring on the outside and on the inside of the brass guide plug, then place it on top of the assembled input stage, with the small end facing out. Use the provided diagrams if needed. Finally, reinstall the retaining nut tight onto the back of the reg body.
For the output stage reassembly, first re-grease the piston o-ring then reinsert the piston into the reg body (with the raised end facing out). Once it's in, reassemble the spring pack group as per the provided diagram. Note that the domed end of the guide pin faces the piston, not the flat end. Then, simply screw the end cap back onto the regulator body.
Smartvalve Maintenance:
If you are unable to shut off the air flow into the reg from the tank, then the inner Smartvalve o-ring is to blame. You can only service the Smartvalve if there is zero psi in the tank. If so, then you can remove it by removing the c-clip from the left side of the manifold around the end of the valve. Be careful that the clip doesn't spring across the room once you remove it. It may take a while to get off.
Pull the Smartvalve out the other side of the manifold. Clean the old grease off the two o-rings around the valve (outer rings), then clean the inside of the manifold where the valve goes. Re-grease the outer o-rings as well as the inner o-ring visible down in the bore where the valve goes. Replace any o-rings if necessary.
O-Ring Diagrams:
If you need to replace any of the rings used in the regulator, here is a diagram of the sizes and durometers:
The tank seal o-ring (907/90) isn't a size you will find at any local stores. Also, the fill nipple o-ring is a 6/90.
Demonstrational Videos:
This video shows disassembly of the reg, quick cleaning, and reassembly:
Max-Flo manifold maintenance, high-res (33-MB)
Max-Flo manifold maintenance, low-res (14.7-MB)
These other videos show maintenance of the smartvalve knob:
Smartvalve maintenance, high-res (13-MB)
Smartvalve maintenance, low-res (5.8-MB)