The rubber mold that fits between the windshield and the right exterior body (that runs from the top of the van to the bottom of the windshield)is loose. It is attached at the top and the bottom but wants to float out in the middle. It looks like it has small holes in the rubber mold which fit into a pocket. How can I get it to stay in place?

my suggetion is if the windsheild was replaced the water is getting under the molding through the top or top side of windshield and traveling down the channel under the molding to get into ur car one way to check this is take real soapy water and just pour it along the the top annd side of windsheild on side that is leaking .. see if that is the substance getting in .....

Since it is both sides, I would be suspect the seal at the bottom of the windshield-remove the wiper cowl and maybe even the wiper assembly to see if a rubber seal has moved or been dislodged-look at all the seals around the windshield itself too, you may need to remove the molding to inspect it. A good body repair shop will find this problem pretty fast.

Removal & Installation

You'll need Windshield Installation Kit E0AZ-19562-A, or equivalent urethane installation kit, and a helper.

1. Remove the windshield wiper arms.
   
2. Remove all windshield exterior mouldings and retainers.
   
3. Using a electric knife, T70P-42006-A or equivalent, insert the blade under the edge of the glass. Cut the butyl seal as close to the inside surface of the glass as possible. Wear gloves. Have your helper sit in the vehicle, place his/her feet against the top of the windshield and gently, but firmly push outward while you support the glass.
   
4. Temporarily position the replacement glass in the windshield opening using spacers to prevent glass to metal contact.
   

Adjust glass side to side to the best glass-to-A-pillar weld flange overlap position and adjust the lower spacers if necessary for proper positioning at the top. A minimum butyl tap-to-glass contact of 3/16 inch (4.8mm) on A-pillar, 3/8 inch (9.5mm) on header and cowl is required around the perimeter to assure proper retention and a waterproof seal. Mark this location with a crayon on the outside surface of the glass and a corresponding point of the glass opening. Remove the glass and clean the inside surface thoroughly.

To install:

1. Start at the side of the glass opposite the original butyl splice and place the 5/16 inch (8mm) butyl furnished in the kit on the top of and in a position that assures the 3/16 inch (4.8mm) minimum contact with the glass on the existing butyl remaining on the pinch weld flange.
   

Do not allow the new butyl to overhang the edge of the existing butyl and do not stretch the butyl or bridge the corners of the windshield opening.

1. Carefully splice the two loose ends of the new butyl. The cut line of the splice must taper downward toward the outboard side of the vehicle.
   
2. Using a clean brush, apply the glass primer (supplied with the kit) around the cleaned inside surface and the edge of the glass in the area that will contact the butyl seal. Allow at least 5 minutes drying time.
   
3. Place the glass in the opening aligning the crayon marks.
   
4. Firmly press the glass against the butyl with hand pressure and check to assure that the 3/16 inch (4.8mm) contact between glass and butyl is achieved. A dull spot indicates an area where the butyl is not contacting the glass surface. Apply additional pressure to seal these areas.
   
5. From outside the vehicle, apply liquid butyl sealer around the entire edge of the glass.
   
6. When the liquid sealer has has skinned over in approximately ten minutes, water test the installation.
   
7. Install the moldings and wiper arms.
   

Windshield sealers, 1980-86

Windshield exterior moldings, 1980-86

Windshield moulding removal tool, 1980-86

Butyl tape installation, 1980-86

Butyl tape installation, 1980-86

If this is happening after it rains then I believe the drains of the outside vent trough are blocked. This trough is below the grill that appears at the bottom of your windshield. When you open the hood of the van it is at the back of the engine bay and runs the whole width of the van. Their should be two plastic hoses connected to it one on the left and the other on the right. If these hoses get blocked then the water no longer drains out of the trough and builds up until it enters your van. Pull these off and then see if any water comes out of the trough. You may have to use a screwdriver to clean out the holes in the trough or even remove the grill to see what is blocking them. Another cause of this problem is when a windshield gets replaced but the rubber between the grill and windshield is not put back. And finally another reason can be your AC drain is blocked.

Using a wood chisel or screwdriver, remove the rubber molding around the windshield. Then, from inside the car, put a firm/steady pressure on the glass. It should lift out. clean ALL of the black adhesive caulk from the metal frame and install new black caulk. Press in the new windshield - and reinstall the rubber molding.

no,pull the weatherstrip back nearer the windshield and there are screws hidden under there>

We see this often. There is a rubber bulb type molding (similar to a door or trunk seal) that is approximately 12" attached just above the fresh air intake that's in the firewall on the passenger side. Quite often this rubber part comes off and water is no longer diverted and instead pours directly through your cabin filter (if you have one) and into the right floorboard. To correct it, remove the right windshield wiper and right side of the lower windshield reveal molding (plastic cowling). Apply weatherstrip adhesive into the "U" shaped molding and re-apply into place directly above the cabin filter and fresh air intake. Replace the cowling and wiper. Good luck

ccarver96: 1st the radiator, unless it has been replaced with an aftermarket "all metal" radiator, is going to be aluminum with plastic tanks.
Your radiator should have large round pins about 2-3 inches long manufactured on the bottom plastic tank. You should have something similar on the top tank. These are out near the ends facing downward. for the bottom tank and straight up for the top tank. coming off the lower core support, there should be places with holes and there should be large rubber grommets which fit into the holes and then the pins for the radiator, fit inside the center of the grommets. This way you have rubber isolating the plastic from touching metal.
At the top, there will be brackets which will have rubber rings which fit inside the brackets and the rings fit over each pin on the top radiator tank. The brackets then are bolted to the upper tie bar of the core support. You now have a radiator which is secured within the body of the car but has rubber mounts which keep it from touching metal. That is what keeps the radiator from getting damaged.
If your radiator is getting damaged other than that, if it is touching the body at any other point, the body has been damaged and needs to be repaired.
If the radiator is being blown apart from running hot, you need to have the cooling system checked or give me more input as to where the radiator is splitting. Is it splitting at the seems from heat?

I have exactly the same problem with the same car. Previous owners garaged it and barely drove it. Now that it's parked in my driveway in the rainy Northwest, problem is a lot of rainwater pooling in the rear foot area, drivers side only.
No moisture at all on the passenger side, front or back. And none in the driver's feet area. Just the back seat, driver's side. No antifreeze smell, etc. And this is a problem when the car is parked; it's not water coming in from underneath or rainwater being driven into the car through gaps while driving.
I found two cracks in a part that I believe is called the "eavestrough." It's a single black plastic piece of molding that is screwed against the body over both doors. This seems to be a common problem -- I went to a local junkyard, found the same make, model and year of car and the plastic molding was cracked in exactly the same two places as on my car. Even with all the screws snugged, it's still a pretty loose fit, with gaps that could easily let water drip down.
After pulling off several pieces of molding and trying to figure out what's going on, here's my suspicion: Water is dripping through the eavestrough and, on the outside of the car, down the column between the two doors.
Normally this would not be a problem. But I noticed that there was a little gap between the car body and the strip of rubber molding that runs on the car body underneath both doors. When I removed this molding (it's screwed on and very easy to remove and reinstall with a 7mm nutdriver), I found that water was getting underneath the molding.
But here's the really odd thing: In addition to the screwholes for the screws holding that bottom molding on, there are three larger holes drilled into the car body underneath that molding. It was apparently made that way (the holes are painted). I'm completely mystified why Buick would leave holes in the outside of a car body like that. They're clearly not drain holes.
My best guess is that that's where the water is getting in. It runs down the pillar between the doors, pools on the rubber gasket/molding beneath the door, and then drips right into the car body through one or more of those holes. The area behind the driver's seat just happens to be the closest, lowest point in the car, so the water pools there.
Today, I sealed everything with a good, clear silicone sealer. Sealed all the gaps in the eavestrough, plugged those three exterior holes under the molding, and added a bead of sealer to the gasket below the door. For good measure, also put a squirt of silicone in every screw hole before reinstalling. I wet-vacced the carpet, which I'm trying to dry as quickly as possible.
If this doesn't work, I'll post more about next steps.

You could replace the sensor or try disconnecting the DRL control module .What relay was replaced ? I see no relay on wiring diagrams or in service info. Replacing the Daytime Running Lamp (DRL) Ambient Light Sensor isn't hard . Just take the top dash pad off ,easy .
Removal Procedure
Remove the instrument panel (IP) upper trim. Refer to Instrument Panel Upper Trim Pad Replacement in Instrument Panel, Gages and Console.
Remove the security system LED. Refer to LED Indicator Replacement - Vehicle Security System in Theft Deterrent.
Twist the DRL sensor counterclockwise in order to remove the sensor from the IP upper trim.
Remove the DRL sensor from the wiring harness.

Removal Procedure
Remove the windshield garnish molding. Refer to Windshield Pillar Garnish Molding Replacement in Interior Trim.
Important: Remove the upper trim panel slowly, the retainer clips could possibly fall into the instrument panel.
Lift the instrument panel (IP) upper trim panel approximately 51 mm (2 in) and pull rearward to release the retainers.
Remove the DRL ambient light sensor. Refer to Daytime Running Lamp (DRL) Ambient Light Sensor Replacement in Lighting Systems.
If equipped, remove the sun load sensor.

Pull the windshield garnish molding from the A-pillar in order to disengage the retaining tabs and clips.
Remove the windshield garnish molding from the A-pillar.

Daytime Running Lamps (DRL) Control Module
Left side of the IP

Removal Procedure
Disconnect the battery negative cable. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical.
Remove the instrument panel insulator. Refer to Instrument Panel Insulator Panel Replacement - Left Side in Instrument Panel, Gages and Console.
Slide the daytime running lamp module from the bracket.
Disconnect the electrical connectors.