Usually this is caused by worn pump seals. There are a total of 3 seals in each pump of the 140C (two on the 140D), and their deterioration can cause solvent leakage. In addition, the NewGuard (Aquapore RP-18 75M) column may also be responsible for shifting retention times. This column should be changed every 3 to 6 months. The guard column (part no. 401883) of the Procise-cLC should be replaced weekly.
