May act as a protein phosphatase and/or a lipid phosphatase. Co-chaperone that recruits HSPA8/HSC70 to clathrin-coated vesicles (CCVs) and promotes the ATP-dependent dissociation of clathrin from CCVs and participates in clathrin-mediated endocytosis of synaptic vesicles and their recycling and also in intracellular trafficking (PubMed:18489706). Firstly, binds tightly to the clathrin cages, at a ratio of one DNAJC6 per clathrin triskelion. The HSPA8:ATP complex then binds to the clathrin-auxilin cage, initially at a ratio of one HSPA8 per triskelion leading to ATP hydrolysis stimulation and causing a conformational change in the HSPA8. This cycle is repeated three times to drive to a complex containing the clathrin-auxilin cage associated to three HSPA8:ADP complex. The ATP hydrolysis of the third HSPA8:ATP complex leads to a concerted dismantling of the cage into component triskelia. Then, dissociates from the released triskelia and be recycled to initiate another cycle of HSPA8's recruitment. Also acts during the early steps of clathrin-coated vesicle (CCV) formation through its interaction with the GTP bound form of DNM1 (By similarity). {ECO:0000250|UniProtKB:Q27974, ECO:0000269|PubMed:18489706}. This is the function of ENSG00000116675 (DNAJC6, DnaJ heat shock protein family (Hsp40) member C6).