Hoses in the back of a 71 bus compartment

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In the left side of the engine compartment there is a 1/2" diameter woven hose coming out. It comes out of a perfectly fitted hole in the vertical sheet metal and appears to have a plastic fitting to it. there is also a small cylindrical object attatched to the side support (as soon as you open the engine compartment look to the left and there it is) with a slot through the middle like it's designed to be turned with a screwdriver and has a line running to it (electrical) Anyone know what the function of these might be? Thanks

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is that your vacuum hose for the disk brakes? '71 was first year for disk brakes and last year for Type 1 engines and lots of times you (like my '71) you don't have a manifold with a valve stem for that hose.