PilotofCorvette

I was installing side duct chrome screens and noticed that the two vacum lines coming from the vacum tank were disconnected. I have a copy of the GM service parts diagram but it does not indicate where each line connects to. Does anyone have a photo that shows where to reconnect the two vacum lines. Also, could this be the reason that the A/C fan has a very low air flow output? I can increase the setting to max flow and you can barely feel the air coming out.

Dan_the_C5_Man

Ask "SpeedyZ06" (I think that's his handle), he has some excellent pics. Yes, the doors for the A/C - heater vents aren't opening and closing properly since they rely on the vacuum lines.

The down-side here is you'll probably have to remove the fender to get to what you need. I would also question why these lines were disconnected in the first place.

Bill Dearborn

Here are the instructions for replacing the tank. The related diagrams will not show up in a post. Hose 4 from the I/P goes to the top of the check valve and Hose 5 goes to the bottom.
Vacuum Tank Replacement
Removal Procedure

Remove the RH front tire and wheel assembly. Refer to Tire and Wheel Removal and Installation in Tires and Wheels.
Remove the RH front wheelhouse filler panel. Refer to Wheelhouse Filler Replacement in Body Front End.
Remove the PCM. Refer to Powertrain Control Module (PCM) Replacement in Engine Controls.
Tape off the rear edge of the RH fender and the front edge of the RH door to prevent scuffing.
Open the RH door.
Utilizing the opening between the fender and the door, remove the screws retaining the vacuum tank (1) to the hinge pillar (3).
Working through the wheelhouse opening, disconnect the I/P harness vacuum connector (4) from the vacuum check valve (2).
Disconnect the engine harness vacuum connector (5) from the vacuum check valve (2).
Remove the vacuum tank (1) from the vehicle.
Disconnect the vacuum check valve (2) from the vacuum tank (1).
Installation Procedure

Connect the vacuum check valve (2) to the vacuum tank (1).
Position the vacuum tank (1) to the vehicle.
Connect the engine harness vacuum connector (5) to the vacuum check valve (2).
Connect the I/P harness vacuum connector (4) to the vacuum check valve (2).
Have an assistant position and hold the vacuum tank (1) against the hinge pillar (3).

Notice
Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.


Utilizing the opening between the fender and the door, install the vacuum tank (1) to hinge pillar (3) UPPER retaining screw FIRST (net locating position), then install the lower screw. Tighten
Tighten the vacuum tank retaining screws to 3.5 N·m (31 lb in).

Close the RH door.
Remove the protective tape from the edges of the RH fender and door.
Install the PCM. Refer to Powertrain Control Module (PCM) Replacement in Engine Controls.
Install the wheelhouse filler panel. Refer to Wheelhouse Filler Replacement in Body Front End.
Install the tire and wheel assembly. Refer to Tire and Wheel Removal and Installation in Tires and Wheels.

Hope this helps.

Bill

PilotofCorvette

Many thanks for your feedback. I bought this car used and it has evidence of the infamous exploding battery so I guess someone was in there "repairing" some vacum lines??