Exchange the Solvent Selection Valve

When

If leaking internally (crossflow between the ports), or if one of the channels is blocked

Tools required

Qty.		p/n	Description
1		8710-0899	Screwdriver Pozidrive Shaft

Parts required

Qty.		p/n	Description
1		5067-5895	Solvent selection valve

Prerequisites

Switch off the pump at the on/off switch

Lift solvent bottles out of the solvent cabinet and place them on the table. Disconnect the solvent tubes from the solvent selection valve and empty the tubes into the bottles. Place the bottles back into the solvent cabinet.
Disconnect all tubings from the solvent selection valve.
Using a screwdriver, loosen the holding screws of the valve holder.
Carefully pull the valve holder out.
Disconnect the valve cable from the internal connection socket by pressing the fixing clip through the left side middle hole with the screwdriver.
Completely remove the old valve.
Bend the cable at the connector of the new valve.
Guide the cable and connector into the hole and push the connector into the socket.
Exchange the defective solvent selection valve.
Tighten the screws of the valve holder.
Reconnect all tubings to the solvent selection valve.

NOTE

After an exchange of the valve it may be required to pump several mL of solvent before the flow stabilizes at a pressure ripple as low as it used to be when the system was still working properly.

21-Jun-2025