Reply To: FX Pump Rebuild



I used water-pump pliers and the strap from a strap wrench to hold the large piston while turning the main valve housing:

and got separation!

I can now remove the 5mm bar (hi pressure piston) but the large piston is still connected to the 10mm hydraulic pipe…

There are two features on the large piston that need explanation.

The first appears to be a notch for a pin wrench, a matching notch is on the opposite side.On closer inspection, it appears to be an air passage as it passes through the brass collar into the O-ring land.

The second arrow indicates a hole (with matching hole on opposite side) that dead ends against the 10mm pipe. This might only be a transfer port for lubrication, nothing else comes to mind.