I am doing the Coolant Reservoir Repair/modification as per "907IE Tech FAQ>Coolant Reservoir Repair" since my expansion tank recently split again (after overheating because the fan broke). I have it all done, according to the instructions except I am not sure about the the very last instruction:

"Now remove the rubber gasket from the coolant tank cap and cut a slit from the I.D. to just beyond the cap’s inner relief valve." OR in another post it is worded, "and cut a slit that allows it to vent thru the center valve in the cap."

Not sure where I cut this slit? See this photo - by any chance, does anyone know if this is right? Or is it a cut inside the coolant tank neck?

I understand it's about making the cap non pressurised, so I think this would do it - just checking before I take the knife to it

Help appreciated.