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Vacuum Hoses On Air Filter Box 98 S70


scienceguy

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OK...so I'm getting ready to sell my 98 s70 and am changing out plugs, wires, etc when I notice a broken vacuum elbow on the back of the air filter box. As i investigate further, it disintegrates in my hand leaving me with a crumbled elbow and a small black vacuum hose, neither of which are attached anywhere. The other elbow and (white) tubing are still attached. Where does the other end of this second (black) vacuum hose connect. It it the shorter of the two hoses and cannot venture to far from the air filter. HELP!!!

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OK...so I'm getting ready to sell my 98 s70 and am changing out plugs, wires, etc when I notice a broken vacuum elbow on the back of the air filter box. As i investigate further, it disintegrates in my hand leaving me with a crumbled elbow and a small black vacuum hose, neither of which are attached anywhere. The other elbow and (white) tubing are still attached. Where does the other end of this second (black) vacuum hose connect. It it the shorter of the two hoses and cannot venture to far from the air filter. HELP!!!

The vacuum hose goes from the top of the air box, to the BOTTOM of the airbox just above the intake port of the box. It controls the warm/cold air mix. On the inside of the top cover where the ports are, theres a valve that opens and closes with ambient temperature. Because the top of the box has a constant vacuum, when the weather gets cold and that valve opens, it sucks on a door at the bottom of the airbox (sliding it open slightly).

This allows warm air from the metal flex hose above the exhaust manifold to enter the box to assist during cold starting situations. When its warm out, it keeps the valve closed, so theres no draw on that door, thus only allowing cool air to enter the airbox.

It's hard to see the port, but if follow the intake tube (from the front of the car) to the bottom port of the box, just above the port theres a connection for the vacuum hose.

on my 850 granted its a 93 there was this little thing that it connected to, tho i just bypassed it

that's smart.... :rolleyes:

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The white vac line runs from the back of the airbox to the vacuum tree

The black line runs from the back of the airbox to the front of it (where the air intake from the grill attaches to the airbox) - it controls the airbox hot/cold flap which is vacuum actuated in later model 850's and S70's

Earlier models have a mechanical thremostat (no vacuum lines) in the air box which is prone to fail.

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The white vac line runs from the back of the airbox to the vacuum tree

The black line runs from the back of the airbox to the front of it (where the air intake from the grill attaches to the airbox) - it controls the airbox hot/cold flap which is vacuum actuated in later model 850's and S70's

Earlier models have a mechanical thremostat (no vacuum lines) in the air box which is prone to fail.

yer too slow.... B)

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