Vacuum question

[framey]

Hi,
a quick question please.....
The vacuum tank behind the alternator - there are two vac lines plugged into it. I found that one dissapears under the UIM(front), but the other has half a check valve on the other end(rear).
When I suck on the front one the valve is letting through. When I blow the valve shuts maintaining pressure.

If this is a vacuum tank how come the check valve lets in air when vacuum is applied?

What gives?

btw I suspect my PRC solenoid is not working.

Thanks

[nikp]

It\'s a pressure tank, not a vacuum tank. It\'s meant to hold up to 10psi of pressure.

[framey]

D\'OH!!

OK thanks!