On my '78, I'm noticing water dripping down the inside of the hinge pillar. While it's not a ton of water, ANY water in that area makes me extremely uneasy. FYI, I've removed the old interior components (to install new), I also installed weatherstripping and had a new windshield installed.

I have tried the water hose treatment, but it isn't really clear where this is coming from (other than it is obviously from the front and not coming from the window). I've pulled the weatherstripping off and resealed, I pulled the trim around the windshield but didn't see anything obvious. Like I said, it's just a drip, but after a day of rain last week, it left a puddle in the floorboard. Any suggestions on finding this? Thanks, Paul.

 

I'm having a hard time picturing where this water drip is coming from. Can you snap a picture of the area, and draw an arrow tot he spot where it's dripping from?

 

Sounds like its coming in on top of the #2 mount, typical leak on these things. you may have some bird cage holes you will not be able to see with the fenders on. there is a piece of fiberglass rivited to the birdcage that is there to bond the back of the front clip to. The rivet holes rust out and because of the way its built water stands under that part. You MIGHT be able to stop it by sealing the area between the rear top edge of the fender and the corner of the windshield.

 

It appears to drip right on top of the body mount bolt inside the A-pillar. If that doesn't explain it, I'll try to get a picture tomorrow (sun's gone down tonight)

I did search the archives (as I know mine is not the first C3 to leak )From my search, some of the folks are talking about the vents leaking (fresh air vents?) and how the drain may be clogged. Where is the drain located? Also mentioned leaking through the cowl. Any way for this water to drain down the A-pillar?

I saw the talcum powder suggestion any one had any luck tracing the leak with this method?

Paul

 

Did you ever get that picture to help us visualize all of this?

 

JUST A QUICK NOTE....I HAVE A ALSO A HEAVY WATER LEAK ON THE PASSENGER SIDE OF MY 77 COUPE. AND IT HAS TAKEN ME AWHILE TO LOCATE THE SOUCE, I LOOKED AT ALL THE PLACES THAT YOU HAVE AND DID WHAT I THOUGHT WOULD SOLVE MY CONCERN. HOWEVER I HAVE FOUND, BY USING A HIGH PRESSURE WATER SPRAY..SUCH AS A CAR WASH BAY HAS... AND FORCED THE ISSUE. WATER WAS POURING IN FROM THE FRESH AIR VENT DOOR ON THE PASSENGER SIDE KICK/VENT PANEL...NOW, I JUST HAVE TO GET ABOUT TO INSPECTING THE VENT DOOR MECH/ASSEMBLY... UNTIL I HAVE THE TIME, I DO NOT KNOW WHAT OR HOW TO CORRECT THIS AGING RELATED PROBLEM.

 

Hmm...well, I suppose you can remove the rod that actuates the door so the faulty actuator isn't holding the door open...and seal it shut.

 

Well, here is my thoughts;
First pic is the pass side lower WS corner, the red circles are the rivet holes that hold the fiberglass anchor on for the rear edge of the fender. If the rivets are loose they will leak. There is a seam there also right above the Red Line that can leak if not sealed.


This is the door mount pillar pass side. Mine was missing a bolt on the lower hinge and there was a slight gap on the lower forward bolt hole on the top of the bottom hinge, both allowed water to enter the pillar on top of the #2 mount


Image 3 is the Pass side Lower WS corner with the fiberglass anchor sitting in place, again the circles indicate the rivet holes that hold it in place. Again the line shows the firewall seam that can leak. It looks like it was sealed with wax.


This is the upper edge of the fender anchor where it actually attached to the WS lower corner, as you can see the fit is something less than close. This is under the rear edge of the fender right below the windshield. There is no sealant here. Water gets trapped under the fiberglass anchor and corrodes the corner below it. When this part goes back on it will be painted with POR15 and sealed with silicone and attached with sealed rivets. For a quick fix you can silicone this seam, use a LOT


This is the Drivers side lower WS corner, it was pretty much swiss cheese when I took it apart. Bubba actually did a fair if not propper repair on it sometime in the past,it was bondoed completely full.
The red circles are the rivet holes, The green is the pitting that did not quite eat all the way thru the metal and the Green is the area I cut out and need to make a patch for.


This is another area that leake, corroded and gone upper WS frame section, Bubba didn't do quite so good here, I still need to cut it out and patch. Once its all patched, it will be comletely POR15'd and new glass installed after the body is back on the frame.

I think you said you have already put in a new windshield and you should have found any WS frame cancer and fixed it at that time.

 

Excellent description on the leak problem.

That should be more than enough to scare the hell out of him

That's why I keep a tarp with me all the time.

 

Lol

 

Man I'm sorry you had to go through all that...you are done with it all aren't you?

 

Nooo. About the time I got a welder rounded up it was time to quit for the holidays, then I had a few other things get in line ahead of the car. But, next week I am on it again, Tuesday night I expect to get the patch in the #2 mount pocket and weld in the repair rail on the pass side. If that happens like it should the drivers door and the fiberglass door sills will come apart and I'll do that one, it will go faster than the pass side, I had to reteach myself how to weld. THEN the patch work on the WS frame. Then I am going skiing

 

Good Morning, Sixfooter,
Your exploded view photos are showing me a lot of the details that will be beneficial to solving my water leak concern. I am going to use this information to address the total problem.....however ....I am wondering, if by chance you might have some other photos showing the details of the passenger side inside and outside of the freash air vent door opening construction.
Also, in closing do you think I will have to explain to my family...why I am looking at naked covette pictures ...on the internet?
Thanks for your time. R.OLEN

 

Good morning
Yes I can get you some more detail no problem, but it will be this evening. Glad the detail helps.
Your on your own explaining any nakedness on your computer, I call all mine "Research"

 

OK, here are some more pics;

This one shows the Vent door pass side from the outside closed, not a lot to see, but you can see the whole plenum and blower.
The grill at the top is there to keep most leaves and large debris out of the plenum area.

This is the vent door operator from the inside, you can't see it from here but there is a wire that connects a tab on the operator to the door, the vacuum comes from the selector switch on the console.

This is the Fresh Air door flapper, its mount and the fiberglass anchor for the upper rear edge of the fender in its approximate mounting place. The door defaults open, allowing fresh air from outside to come in thru the blower and directs it thru the AC plenum and in the dash/floor vents. Vacuum to operate the flapper comes thru the firewall and then from the console controls and a vac valve unde the dash

This is the backside of the flapper with its operator exposed.


Here is annother view from the top, you can see how everything is related. Keep in mind that the fender, these two pieces, the firewall and the verticle piece of glass in front of the door form the plenum to control the air and if everything is sealed at the top and front will also control how the water flows. Yes it is supposed to flow thru here, from the wiper tray, thru the grate and down and out thru a slot at the bottom below the vent door. Frequently the slot gets clogged with 25+ yrs of dirt, leaves, rat turds etc..that makes the water backup into the bottom of the vent opening. The wide lip around the vent door duct is supposed to stop the water running down the plenum from coming in thru the door.


Hope this helps

 

Yes, this is going to give me all the research pictures necessary, and with your first hand knowlege about the C-3 machines....I should be able to cope with this concern quickly. It is gratifying to meet someone dedicated to doing a good job. Your efforts and those of this C-3 Community..are sincerely appreciated . See Y'all Down The Road!
Olen Reedy

 

Sixfooter, You seem to know your way around this area, so I thought I'd ask. I bought a kit to re-do the insulation on the vent door itself, but the old stuff is long gone and I can't tell how it was attached. Is it put together as a sandwich, with the bulk of the material between the two surfaces, and material stickiing out around the edges to seal to the inside of the vent plenum??

 

Thats exactly how its put together. There are 4 rivets holding it together. Where did you get your kit?

 

Corvette America has it, part # 33874, cost $12. Comes with new rivets