E61 water discharge is too little. Coffee puck is wet.

[CUBANERO]

I have a Bezzera Giulia with E61 and water tank. When I am pulling shots the water discharge at the water tray is too little and slow. The puck is wet if I pull out the portafilter immediately and sometimes pressure is released through the gasket seal (creating a mess). When I wait for 30 seconds and pull out the portafilter everything looks right. The Coffee tastes good.

[Giampiero]

Maybe or a great obstruction inside the lower part of the E61 or some badly worn valves shaft (pre-infusion and drain valves).
Do you regularly backflushing?

[CUBANERO (original poster)]

I am not regularly backflushing but I use a kilo of coffee every month or two. Recently I I backflushed with cafiza very intensely for 20 times in a row. The situation is now a little better. I don't want to stress the pump too much.