Bolt Size for compression hose sub assembly

Hello

Can anyone tell me the size of bolt for holding compression hose sub assembly in sienna 2008 FWD 3.5L LE model? Does it cause over heating by any chance if it is missed?

my Van has gone through, overheating, stall, random misfires, gross leak. I have replaced every part that u name. Ignition coils, spark plugs, fuel injectors, alternator, starter, battery and finally fuel pressure regulator. All of that cleared. After all this, overheating came back with steam coming out of radiator cap while the van is in idle for 5 mins. Mechanic is saying there maybe leak in radiator. Please help.