Vacuum in-line diaphragm/check valves

[James West]

Hello,

In the engine compartment, there are two small in-line vacuum diaphragm or check valves that go to the fuel tank evaporation cannister and to the EGR control module or what ever it's called. These two valves are half black and half light gray and have the letters VAC molded on them. I need to know which direction each of these two valves point. for each valve, what direction does the gray end point, towards the front of the car or towards the firewall? I think I may have mine installed incorrectly. Please email me directly at jwest@oppd.com with any help that you can give me.

Thanks,

 

[scottyb]

They are there to prevent boost from going to the items that they lead to. I don't remember which way (color), but you can blow/suck them to decide. If you can suck, but not blow in one port, then that port is connected to the vacuum block in top of the intake.

If you can suck and blow same port then the check valve is bad.

 

[6=8]

The side that is labeled VAC on the little valve itself is the side that faces the vacuum source (From the engine).