BFRC 2018 RM-Z450

These are supplimental instructions for filling a shock with a bladder and a bleed port through the bladder. For general Vacuum Master Instructions click here.

Bladder Adapter
Bladder Adapter Plate

Insert circlip
Bladder Adapter pulled up to circlip ready for the plate to be installed

1 - Rebuild the shock dry (without oil and Bladder).

Tip - You can start with a normal rebuild with oil already in the shock to save time refilling the tank over the long haul. 

Mount the shock in a vise (no spring) with the top of the reservoir facing up.

Select the appropriate Bladder Adapter. Insert the Adapter into the Reservoir and install the stock clip.
Thread on the Bladder Adapter Plate (TSVM ABP70) and tighten it. Attach the Fill Hose and open the Fill Valve.
The Fill Valve will remain open throughout the filling process.
Bladder Adapter installed with Adapter Plate
Fill Valve Open

Pressure Valve Shut
Vacuum Valve Open

2 - Draw a vacuum in the shock. 
Turn on the Vacuum Pump. Open the Vacuum Valve on the top of the tank.
The shock will compress as the air is vacuumed out. Let it continue to draw down for about 15 seconds. Turn off the pump and close the Vacuum Valve on the tank.
Shock Collapsed Under Vacuum

Pressure Valve Open
Vacuum Valve Shut

3 - Fill the shock with oil.

Open the Pressure Valve (50 psi) to fill the shock with oil. Do not worry about the “air” in the fill hose as these bubbles are actually vacuum pockets, not “air”.

The shock will extend as it fills. Twist the shaft if you need to help it along.

After the shock is fully extended, stroke the shock a few times.

Shock Extended Under Pressure

Pressure Valve Shut
Vacuum Valve Open

4 - Depressurize the Oil Tank.
Close the Pressure Valve. Then slowly open the Vacuum Valve. This will release pressure through the pump.
If you open it too quickly or you are using too much positive pressure it will blow oil back out of the pump vent.
Repeat - If you would like you can repeat the procedure but it is usually not nesessary.

Adapter Plate backed off to Connector

5 - Remove some of the excess oil.
At this point there is too much oil in the shock. Depressurize the tank by opening the Vacuum Valve.  Leave the shock shaft extended. Back the Adapter Plate off until it hits the Fill Hose Valve.
Then, while holding the shock shaft down, press the Adapter Plate down to the top of the reservoir. Some, but not all, of the extra oil will be pushed out of the shock.
Disconnect the Fill Hose from the Adapter. Remove the clip and the Adapter.
Adapter pushed down to Plate to remove some excess oil

Bladder Collapsed

Pressurize to 2-3 psi

Bladder Full

6 - Put the Bladder on the Cap and pressurize it just enough so the bladder is full (2-3 psi)(not collapsed).  With the shock shaft extended insert the bladder assembly into the Reservoir, allowing the oil to overflow.
As the bladder is being installed it will seal and become very difficult to insert further. Let the pressure out of the bladder so it can be more easily inserted.
To avoid waste, you can remove a bit more of oil from the reservoir before inserting the bladder. However, make sure there is enough oil in the reservoir so it overflows when the bladder is inserted.
Immersing Full Bladder into reservoir must cause oil to overflow

Insert Clip

7 - Insert the Clip and seat the Cap on the Clip.

Open up the Bleed Port

8 - Reposition the shock in the vise so the Shock Bleed Port is pointed up at the highest point on the shock. Open the Bleed Port on the shock.

Pressurize the Bladder to 2 to 3 psi

9 - Pressurize the bladder to 2 to 3 psi. This will expand it to its full state and cause excess oil to overflow. It only takes a few pumps and may not register on the gauge.
The pump shown is a mountain bike shock pump.

Close the Bleed Port and pressurize the shock with nitrogen.