The hoses attach to plastic quick connectors at the firewall. They can crack and leak. You'll need the tool to disengage the connector from the core inlet/outlet. They're inexpensive plastic sleeves available as a set, or by the individual size (Harbor Freight or parts store items). There may be a repair connector available, or the hose as an assembly. We replaced one quick connector on my son's 2007 Classic 1/2 ton about a year ago. One hose was clamped to the connector, while the other was a hose assembly, bonded to the connector. The failed connector was the clamped one. I don't know if the other can be replaced with a clamped connector or if the hose requires replacement as an assembly, although it looks like a clamped connector would work. The replacement was simple with minimal coolant loss (less than what was leaking), but access is tight.