Tools you will need:
7/16" open end wrench
9/16" open end wrench
Flat blade (med) screwdriver

Preface:
Discharge problems are typically caused by excessive amounts of toilet paper. Therefore if a  problem abruptly occurs it is advised that the joker valve area as well as 'Y' selector valves or 90° connections be checked for debris.
  In most applications calcium carbonate will accumulate in the head system and will result in a slow reduction in the discharge line diameter.

See animation (right) for function and flow.

Normal Operation

Discharge flow path:

The Up Stroke
The waste water enters the bowl mounting area through the base assembly part# 1248W and into the housing (due to the vacuum generated). Simultaneously the flapper valve lifts and allows waste water to enter the housing.

The down Stroke
The brass weight mounted atop of the flapper valve part# 1228CW in conjunction with the downward pressure of the piston closes off the entrance to the pump assembly and creates positive pressure. The Joker valve part# C253 then opens and the waste is displaced through the discharge fitting.

Joker valve part #C253

a.) Distorted due to prolonged exposure to chemicals and or restricted discharge system.

In this instance, the joker valve cannot open freely when under pressure (down stroke) and will result in a restricted discharge performance.

b.) Distorted due to excessive calcium carbonate buildup or chemical exposure.

In this instance, the valve will not close when under a vacuum (up stroke) thus allowing waste water to transfer back into the pump housing resulting in a degradation in discharge performance

Flapper valve part #1228CW

If the flapper valve is not fully closing over the base opening it will result in improper waste water transfer (not isolating the pressurized pump on the down stroke). Also chemical contamination can cause the rubber components to stiffen and or distort.