Sometimes the pipes just need to be cut--but that's only sometimes. The original Volvo clamps rarely pinch the pipes the way regular U-shaped clamps pinch. Hammering with sharp flat blows against the outer pipe of a slip on connection will usually stretch the metal enough to get it loosened and with some WD40 or other such product applied the connection will wiggle apart. If the hammering seems to need to be done full circle it may be helpful to just drop the entire system. I give a good smear of high temp silicone sealer (red/orange) on the inside of the new connections--makes doing adjustments and/or later disassembly easier--even after years. -- Dave