The lift arm by-pass orifice is located in the port with the 90° fitting (Item 1) [Figure 20-40-5].
The pressure differential/check valve (Item 2) must be removed to remove the fitting (Item 1) [Figure 20-40-5].
Use a flat blade screw driver to remove the lift arm by-pass orifice (Item 1) [Figure 20-40-6] from the BICS valve.
Check the condition of the orifice (Item 1) [Figure 20-40-7] and replace if needed.
The orifice hole must be 0.0785 inch (1.994 mm) diameter.