Intake manifold vac hoses

[Liamc111]

I see 3.5mm and 4mm spoken of often but the 3.5mm is hard to come by in the uk. Is 3mm too tight to use? Would rather they be tight than use 4mm and run the risk of it popping off.

 

[Mid Night FD]

I think i got 3mm when i did mine a couple of years ago (cant find the link to check ) as i had the same issue of not finding 3.5mm. Its good practice to put tiny cable ties on the ends, epecially on the boost/map sensor. Maybe get each and see as some of the check valves i think i struggled getting 3mm on