Bio-Rad ChromLab™ Software - Manual (Page 162)

A | Maintaining the Instrument
160 | NGC Chromatography Systems and ChromLab Software
3. Use the 3/16" hex key that is provided in the fittings kit to remove the hex bolts
on the front of the pump head housing.
Caution: Avoid pulling the pump head housing off at an angle or rocking
or twisting the pump head housing, as this can cause the piston to break.
4. Carefully separate the pump head from the pump face plate. Pull the pump
head straight toward you.