On29 DEC 2025, Mark Wellard in Australia wrote:
"The hose between the head and thermostat on my twin cam was weeping, no matter what I tried to get the hose to seal. I decided to replace the hose with a slightly smaller ID but it's easier said than done. There are 3 fasteners holding the thermostat housing in place - of course they aren't easy to access. After finally removing them I could open the gap between the two pipes to about 1/2" and was able to get the new hose in place using a neat trick I recently read about.

Tie a cable tie through the hose and reduce the width enough to squeeze it into the gap (see picture). Once in place, reassembly is the reverse of the dismantling process.