Check it before taking it apart. It may be good, it could happen.
It is a bit tricky as I said. I've got the port function identification drawing some where. Let me know if you, or anyone else, needs it. Chuck
I'm thinking I would have to have a dash in the car first. How do I test it out of the car?
Attach the mighty vac to the 4th port from the left as viewed from the front and top (black hose that comes through the firewall when installed).
Cap the other 5 ports, apply 15-20 in.hg. and see how fast the vacuum leaks down.
To test individual ports keep the vacuum source where it is, cap the 4 ports you don't want to check, and attach your trusty vacuum gauge to the port you do want to test. Apply vacuum, and see if it leaks at the same rate as in the first check. If it leaks the same it is a general leak of the vacuum switch as as whole. If it leaks faster it indicate a leak/crack in that port.
Color coding on hoses, left to right: white, brown, red, black, blue, yellow.
A 7th hose that passes through the firewall with the black hose is color coded purple and attaches to the water valve vacuum switch located on the heater/AC box close to the blend door crank arm.
Under the hood the black hose attaches to the small nipple on the vacuum canister and the purple hose connects to heater control valve.
Chuck