Ring filter insert for a liquid filter

A ring filter insert (3) which can be flowed through radially has, in at least one of its end disks (4, 5), at least one connecting channel (28) which runs radially between interior and exterior of this end disk (4; 5). With such a ring filter insert (3), through a liquid supply channel (14) which is conducted through the central inner space of the ring filter insert (3) which serves as the crude space or clean space, it is possible in construction and rational terms to pass liquid through the at least one connecting channel (28) in at least one of the two end disks (4, 5) of the ring filter insert (3) from the radial inside outward into one of the two crude spaces or clean spaces which are sealed from the other crude space or clean space and communicate only through the filter medium of the ring filter insert (3). The flow through the at least one connecting channel (28) in at least one of the two end disks (4, 5) may also be in the reverse direction from the radial outside inward.