Cowl repair suggestions?

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Lenix

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Like many mustangs I've seen here I gotta fix under the cowl, originally I thought to cut a hole out from within the body and fabricate a new peice that would be bolted in with a gasket made, but before committing to somthing like that I want to see if anyone has suggestions, I'm not really looking at removing the windshield and drilling tack welds, but would like to know some more out if the box ideas. Thanks in advance!



 
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There is not a quick fix that really fixes the issue. Removal of the cowl is not easy but remove and replace is only true way to repair. You will need both upper and lower. So if cowl is gone the floors are probably also. Depends on how you value the car it might not be worth the trouble to repair.

 

Mister 4x4

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This is one of the areas where it's best to just bite the bullet and do it right.  Trying to repair something like the cowl is more of a challenge trying to avoid doing it the right way, often with mixed results that will require revisiting it later down the road.

Having done it the hard way myself (drilling out the spot welds, cutting & piecing in 'new' pieces from a donor car, and putting it all back together), I can honestly say that if the reproduction pieces would've been available at the time, I definitely would've just paid the money for those pieces and the simplicity of it all.  I would've just drilled out the spot welds, pulled both cowl panels off in their entirety, reinstalled and sealed the repop pieces, and been done with it all over a weekend, if not just one long day - rather than the several days needed to ensure I had actually gotten everything sealed back up where the piece-meal repairs had been made.

Good luck!

 

mjlan

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Judging by the blower motor bump out in your firewall your's is a non-A/C car, what does your driver's side cowl lower look like?

Non-A/C cars had an opening with baffle on the driver's side as well, and the baffle is what traps debris which leads to rust.

This repair is a significant undertaking but doing it the right way is the only way to really get access to all the damage and get rid of the rust.

The above being said, I think there was somebody here that had patched their cowl from the bottom, or maybe sealed it off as they switched to aftermarket A/C which doesn't require outside air...

DS Cowl Lower.JPG

 
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Mister 4x4

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Yes, the non-A/C cars had the air hats on both sides.  Both sides also had plenums attached having flappers that could open and close to allow in fresh air through the outer vents of the dashboard - the flappers were cable controlled, with the knobs on either side of the center dashboard assembly, hanging down near the heater controls.

The aftermarket HVAC kits provide a block-off plate to minimize the amount of fresh air entering the cabin, and minimize the heated/cooler air leaving the cabin to help with efficiency.  I made another plate and blocked off the other side in my car, but now I'm regretting doing that and wish I would've reinstalled at least one of the adjustable plenums (instructions said to remove them, and the kit provided all new dashboard vent inserts with hoses running directly to the HVAC distribution point).

 

Lenix

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Sweet, I appreciate the replies, my floor pans are most definitely gone as well, got new ones already doing a full restoration, and based off what was said I guess I just learned my car was originally non AC, my main concern with this is I'd like to do what I can to keep water from getting into the car itself, as for AC I think I'm gonna ride with 2WD60 until later, I have a 302 from a parts car and I do not believe that had it either, But a 429 is the end goal which I could retrofit somthing into

All that out if the way I think I'll fill in the one side and repair the other to mock the AC setup and clear some headache dealing with the innards. Might set up a thread in the build section but this is what I'm working with



 
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MikeGriese

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If you are going for a repop cowl, make sure you get the options right. There are different cutouts, holes and brackets between air and heater only cars, like the little doghouse for the heater blower motor that is not on an AC car. The AC plenum mounts differently, there is only one fresh air intake hat (passenger side) there are vacuum lines that need holes - switching to AC later will be a big deal - filling holes the heater only cars use, opening holes the AC cars use. It's engine out/dash out.

 

computercarguy

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At the time I rebuilt mine, the new aftermarket cowl had just come out. Having an a.c. car, I capped the bowl on the driver's side as there was no a.c. version. Big mistake! Clearance  is needed for the windshield wipers as the linkage protrudes slightly into the bowl.

 

Mister 4x4

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Wow - mine was a lot like then once I got all the old interior stuff out of the way.  I hope it goes better for you, but be prepared to find something like this when you open up your cowl.

Driver Side

attachment.php


Passenger Side

attachment.php


And this is what I had to do to repair it - a new set of cowl panels would've had this done in hours, rather than days.

attachment.php


Good luck!

 

kcmash

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I do have a drivers side cowl top hat for a non-AC car.  Saved it for the tophat piece since no one was reproducing back then.

Let me know if I should dig it out for you.

kcmash

 

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If you would like to see some step by step pictures of when I removed mine and refurbished it? go to this post "reworking the rusty Cowl"

Good luck with your build.

 

MikeGriese

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If you would like to see some step by step pictures of when I removed mine and refurbished it? go to this post "reworking the rusty Cowl"

Good luck with your build.
That's a very good thread.

 

Lenix

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I do have a drivers side cowl top hat for a non-AC car.  Saved it for the tophat piece since no one was reproducing back then.

Let me know if I should dig it out for you.

kcmash
I appreciate it but I'll fabricate somthing and try to go along with my original plan I outlined, I'll make sure to take pictures

As for the other lad in the form, I already know the condition of mostly every bit of the car because I've stripped it down and am thankful it isn't as bad, quite tame compared to what you dealt with

 

Mister 4x4

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I do have a drivers side cowl top hat for a non-AC car.  Saved it for the tophat piece since no one was reproducing back then.

Let me know if I should dig it out for you.

kcmash
I appreciate it but I'll fabricate somthing and try to go along with my original plan I outlined, I'll make sure to take pictures

As for the other lad in the form, I already know the condition of mostly every bit of the car because I've stripped it down and am thankful it isn't as bad, quite tame compared to what you dealt with
That's good news! ::thumb::  As I mentioned, my floor and firewall was looking rather similar to yours once I started getting things apart.

 

OzCoupe72

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Either way you go about it I would run a bead of silicone around the hat area to prevent water pooling in the trough

If you patch it I would use a POR15 or similar product on your remaining metal as from your photos it is pitted with rust

I replaced my entire cowl with the repop item but still ran silicone beads to prevent water pooling

 

NOT A T5

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I've used 3M black seam sealer throughout my car rather than silicone.

 

OzCoupe72

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I've used 3M black seam sealer throughout my car rather than silicone.
Yes certainly for all the seams but I meant above the seams and a big enough bead to divert rain water away

This would only be feasible if you have removed the top half of the cowl panel or at least a good part of it though

 

Lenix

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I've used 3M black seam sealer throughout my car rather than silicone.
Yes certainly for all the seams but I meant above the seams and a big enough bead to divert rain water away

This would only be feasible if you have removed the top half of the cowl panel or at least a good part of it though
Bold assumption, jokes a side I think I'll proceed with my going plan and the seam sealer is definitely a fantastic idea, I've finished up my front end and since my car is out side I gotta wait for it to dry up, I'll post pictures as I go, worst case scenario I have to go back a few years from now and redo it right.

 

Lenix

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Ah yes, it's been a while life got in the way, but I went through with my original plan kinda, I took 6" HVAC starter tube and trimmed it down, and fabricated the metal squares I had to cut out, one square was welded in and seam sealed along with paint, then the HVAC piece is being riveted in with a fair amount of gasket maker to hopefully be if not a permanent fix, a long time one.

Snapchat-1761723367.jpg

 
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