well yeah i thought that but the size of the hex key is a bit wierd.
let me get this right the top up thing is on the top of the pump yeah, looks like a small hex bolt.
if thats it its a bloody starnge size cause a 4mil is too small and a 5 mil is too big
so it if there is such a thing a 4.5mil
unless this isnt the correct thing im looking at