LS1Formulation

iTrader: (13)

I'm reassembling my Formula, but it's been 15 years since it's been on the road and I've forgotten where some of the lines go. I have this vacuum line that is for the HVAC system, with what looks like a check valve on the end. One side is broken, and I remember that it always was, so I'd like to fix it correctly if need be. I don't have A/C, I just want to make sure the HVAC controls continue to function. Do I just hook it up to manifold vacuum? I'm going turbo, so I'm going to have a vacuum block and can connect it there. Where does the broken side run to? If anyone has pics of the routing, it would be greatly appreciated.

JacobChevys

I have a 98 as well. I’ll have to check as im putting back everything together but I am almost 100% sure that vacuum goes to the back of the intake manifold.

Once I get my intake and accessories back on(hopefully by this weekend) I’ll snap a pic and show you how mine is routed

LS1Formulation

iTrader: (13)

Thanks! I'm thinking you're correct there. The other end I figured out goes to a piece bolted under the passenger side framerail. A local dealership happened to have a completely stock low mileage '98 SS in their warehouse, so I went and snapped a bunch of underhood pics. I don't know what the piece under the framerail is for, whether it's HVAC related or cruise control related. I'll have to search around to see if I can figure it out.

JacobChevys

Here is that little vacuum line on your car.

JacobChevys

Off that piece you’re missing, it does not go to the intake manifold I was wrong.

It has a 90 on it and turns down and runs back into the wire loom above passenger side fenderwell.

Im unsure where it goes after that.

JacobChevys

I could probably get a video if you need, would be easier to follow than just sending pictures

LS1Formulation

iTrader: (13)

Thanks, I don't have a pic of the place it connects under the frame rail, but I'm about 99% sure that's where it goes. Still don't know what the functionality is of that box, except maybe as a vacuum reservoir.

JacobChevys

I believe it’s a check valve, if you need any other pictures let me know if I can help