If the solenoids go faulty (all too common with the 6HP26) then there’s a high likelihood that the corresponding damper (each proportional pressure control solenoid has its own separate accumulator/damper in its hydraulic clutch circuit) has become worn and ineffective as a result. The damper is made up of a solid metal piston into which is embedded a rubber ‘spring’. The rubber spring flattens over a period of time, becoming permanently deformed.
The accumulators/dampers should therefore be replaced when the solenoids are changed. The Sonnax zip kit replaces this damper design with a cupped metal piston with a traditional wire helical compression spring.
Phil