I have just replaced my header/overflow tank on the cooling system as the old one was starting to leak around the seam and I didn't want to risk it coming apart. The change was straightforward except that the rigid plastic section of hose between the tank and the thermostat snapped where it clips to the cam cover. I have replaced the section of hose between the thermostat and tank with normal rubber hose of the same diameter as the ends of the original.
My question is whether the restricted bore rigid section of pipe serves any particular purpose, or whether I am ok to leave it as it is? Has anyone else experienced the same problem? I was not being rough with the pipe, but the action of disconnecting one end from the tank was enough to snap it.

 

a few months back, the original clamp on mine came loose from the thermostat housing and when I tried to replace the clamp, the rigid tubing was soo brittle due to age and heat, it just fell apart. I replaced it with a section of hose with no noticeable impact - seems to be working fine for me.

 

Same here except it's been two years - still working fine.

 

Thank you both for your quick responses. Looks like I can leave well alone.