Can the hoses and restrictor thingy just be cleaned if the rubber is ok if so what with?

Im sure you can clean them but good luck getting them off and back on without braking :D

never done it but i suppose you could use some brake cleaner

I cleaned mine, they were not "cooked" silly and hard, cleaned easily. Mind you they were not blocked either.

havent you just had your engine rebuilt ?

havent you just had your engine rebuilt ?

 

for future reference more of a general question

yes mate you can clean them as long as there not brittle and u can use brake cleaner or any sort of WD40 !

No problem cleaning them, as long as you can get them off (and back) in one piece. The valves themselves can also be cleaned, but one of the problems is that the springs get weak, so replacement is a good option. The OEM Nissan part is fairly expensive (for what they are), but Mike Feeney does an equivalent part at a greatly reduced price.