GeneinMorris

Just bought a 1972 base model for my 16 yr old daughter & I to restore together. Found the fresh air cowl at the back of the firewall has rusted through big (2"x5" hole) at the heater air intake and leaks into the passenger side. What is this a bodypart/panel called and is it a part that can be purchased? This bowl seems to be welded into the firewall. Also, I'm afraid to try patching in sheetmetal until I understand what caused it. Is this a known design problem and is it caused by a plugged drain hole or something else I can't see?
Thanks for your guidance.

2+2GT

There is no replacement available for the 71-73 cowl, you will have to fabricate what you need, or find a salvage cowl to replace it.

GA_Mach1

welcome to the world of the 71-73 owner. When I first got my 71, there was almost nothing available, now there is quite a bit, and still not enough. My cowl vent hat is shot also, gonna have to get creative in making a new one. It basically rusted out due to old age and constant exposure to the elements. If the drain holes on the sides of the cowl got blocked it would hold water in there and accelerate the problem. Did you get a fastback or a coupe? Good luck with the project!

2+2GT

The 71-73 is the only Mustang Dynacorn does not make a cowl for. We are working on getting them to do it. It'd probably help if more people in your situation wrote or called and asked about it.

http://www.dynacorn.com/site/05joepa...kjoeparts.html

GeneinMorris

2+2GT, Thank you for the insight. Even if they made a replacement, it looks like it's all welded in at the firewall. Does the "cowl" include the underside basin that the heater air intake connects to, or is that another component part? I will also take your advice and ask for it at Dynacorn.

GeneinMorris

Thanks, GAMach1. I have a coupe. How are you going to repair yours? Also, how can I find the drain holes to be sure I fix the cause of the problem? Does the "cowl" include the underside basin that the heater air intake connects to, or is that another component part I may be able to find?

THUMPIN455

Welcome to the forums. There arent as many parts for our cars as the earlier ones, some stuff from them fits, others doesnt. This is one of those things you could make work from another earlier car, but you will be doing patches rather than an entire piece.

There are baffles in the cowl that keep the water from getting inside the car, they are sort of horn shaped and about 3" tall. The bottom rusts out around them from debris collecting there over time. Since nobody makes a set you will have to fabricate them or find someone who will, finding them in good shape in a donor is going to be near impossible, never mind teh effort to get it out. I am going to make repair patches for my 71, but the trick is getting the hole in the right spot at the right height in relation to the rest of the cowl and firewall so the heater box can properly connect to it.

Dont even consider using anything other than metal to fix it, and a sealer on top is a must. The way I am going about it means I have to get creative with sealing the welds since my HVLP wont fit inside the cowl, but it does save me from drilling all the spot welds and rewelding them after the repair.

I am doing mine from the bottom, since nobody makes a repair panel and I already have the dash and heater box pulled from the car. Yanking the dash is no small task, but Its pretty much the only way to effectively repair the cowl, either going in from top or bottom.

This is inside the passenger side under teh dash, you can see the baffle in this pic, it looks like a wide bottom funnel.


This is the drivers side, it appears to be solid but really this one leaks pretty bad too.


This is what lies behind the dash.


To repair it from the top requires all the spot welds on this piece to be drilled or cut and then rewelded well enough that the glass will fit without leaking. Doing it from the bottom means overhead welding with sparks and slag dripping in your ears. I weld overhead all the time so its just one of those things I dont mind, I just keep the hot stuff out of the ears.

2+2GT

Any repair on the cowl is best welded from above. Not only is this much easier to weld, but easier to seal and waterproof. You'll have to remove the hood, fenders, dash, and windshield, of course this is normal when repairing the cowl on earlier models. There are about 154 spot welds on the 64-68 cowl. With the proper drill, this is do-able.

I would certainly consider cutting up a 69 cowl to get the repair sections you need.

andrewmp6

Yeah your kinda stuck finding a used one or patching yours.Two sites you might want to bookmark http://www.7173parts.com/ http://429mustangcougarinfo.50megs.com/ both have tons of tech for it.For parts http://www.ohiomustang.com/ and http://www.npdlink.com/ are your best bets good luck with it.

GA_Mach1

There are drains on the sides of the cowl, you have to take off the fenders to see them, you can clean them out from the inside of the cowl, if the mesh cowl covers are in place, they shouldn't get blocked up. I envy thumpin, I wish I had a garage I could tear mine apart in. My garage is just big enough to hold a car, if you dont put anything else in it. The only way to do a real repair on this is to drill the spot welds and take the cowl off, which means the windshield, etc.