water leakage on '65

Is it leaking at the windshield or the cowl area? Was the windshield seal replaced recently? Is it dried and cracked? My 66 was leaking from right above the rearview mirror when it rained. I had the windshield (and rear glass - fastback) pulled and new seals installed, and that solved the problem. If the windshield was recently replaced, it could be that the seal is not installed right, or there was too much flexing before the adhesive had time to set properly. In which case I would take it back to the glass outfit.

If you mean when water enters through the cowl opening and drains into the cabin from under the dash, then you have a problem. There are drain holes at each side of the cowl area (hidden by the fenders) meant to drain water that enters the cowl area while allowing air into the cabin. If those become plugged with leaves, etc, it can lead to rust which can eat through and allow the water to drain into the cabin from under the dash on each side. This in turn can lead to the floor pans rusting through (eventually). This was a common problem with early Mustangs. An alternative to rusting through under the dash would be the drains are clogged and the water backs up until it reaches a point higher than the vent pipes (looks a bit like a stovepipe hat - Abe Lincoln style), then overflows into the cabin. If there is no damage, simply clearing the drain holes and keeping debris out of the cowl should take care of it. (the use of a cowl cover, about $30, or a car cover to keep leaves and such from entering through the cowl vent would be a good idea.)

Step one is get those drains cleared of any debris. Step to is to examine the area for damage (ie rusted through).

Then comes the option, depending on how bad it is, of using a repair kit, which consists of a pipe the fits in there and is sealed and held in place (not sure if it was by screws, rivets, or adhesive) . If it's too bad, you need to go the next step. available through many Mustang parts vendors.

Worst case is you have a major job ahead of you which required drilling out the cowl area welds, removing the cowl section, repairing the damage, welding everything back in place, and refinishing. One of the more expensive repairs listed for a 65/66 car.

If you go to

or and go through their Tech articles, I know some time back one of them did a pictorial of the major repair method.

The following diagram is a simplified idea

________________ _ _ _ ___________________cowl vent level

~~ __ ~~~~~~~H2O~~~~~~~~~ __~~ not draining

0___| |_________________________| |___0-->normal drain | Abe's hats \/ cabin

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1965 Ford Mustang fastback 2+2 A Code 289 C4 Trac-Lok Vintage Burgundy w/Black Standard Interior Vintage 40 Wheels 16X8" w/BF Goodrich Comp T/A Radial 225/50ZR16

Yup. That's what's wrong with mine. Rusted out right by the drivers side wiper shaft. And your right, Spike, the only way to get in there to repair is to remove the cowl.

Thank you for your detailed response..

some additional details I bought the project as my 3rd mustang, so don't know what I don't know on this one (I wanted a 65 fastback,,,,,,,,happy camper, I'll deal with it)

problem is that I've never been in that part of the car before so I don't know what I'm dealing with. Do I have to dismantle the front end or can I add a can of "Mouse Milk" that fixes the problem over time

Here's the cowl repair how-to:

DP Pics of the cars:

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1965 Ford Mustang fastback 2+2 A Code 289 C4 Trac-Lok Vintage Burgundy w/Black Standard Interior Vintage 40 Wheels 16X8" w/BF Goodrich Comp T/A Radial 225/50ZR16

Few people ever go in there so you're not alone. I knew because I read an article on how to select a Mustang in Mustang Monthly, several years ago. It detailed the pros and cons of the different models and years, like rusted out floor pans, etc, and the cost to repair.

Much depends on just how bad the damage is. I do not know if the stove pipe is large enough to get a hand through. The drain ports are to far from the cowl vent itself IMO. If it's not too bad and you can somehow get something like POR to it... who knows.

You have to start by getting under the dash and tracing where the problem is coming from, and how bad it is. Then go from there whether it's just a case of unblocking the drain ports, and letting it dry out, or using a repair kit, or going the whole nine yards. Your need to remove the fender(s) to get to the ports IIRC. A wire hanger should clear any blockage, but you still have to get the garbage out so it doesn't block again. Use some experimentation with an air hose and a vacuum. After it's dry, try to blow the stuff to the middle vent area and suck it out with the vacuum.

Otherwise, turn the car over and shake the stuff out... LOL... sorry, but a little humor is needed when deal>Thank you for your detailed response..

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1965 Ford Mustang fastback 2+2 A Code 289 C4 Trac-Lok Vintage Burgundy w/Black Standard Interior Vintage 40 Wheels 16X8" w/BF Goodrich Comp T/A Radial 225/50ZR16

I've found that the early cars also tend to leak from where the upper cowl attaches to the lower through the seams. The sealant tends to crack and allow water to get in. You have to remove the fenders in order to reseal the joints. People often mistake this for a leaky windshield seal and it will drip profusely while driving in the rain.

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1965 Ford Mustang fastback 2+2 A Code 289 C4 Trac-Lok Vintage Burgundy w/Black Standard Interior Vintage 40 Wheels 16X8" w/BF Goodrich Comp T/A Radial 225/50ZR16

Man. Wish I was that lucky. I've been drillin' spot welds for two days now...

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1965 Ford Mustang fastback 2+2 A Code 289 C4 Trac-Lok Vintage Burgundy w/Black Standard Interior Vintage 40 Wheels 16X8" w/BF Goodrich Comp T/A Radial 225/50ZR16

Hell, I may bitch about it, but I'm still having fun. Figure one more night and I'll be welding in a patch. Then on to the next hole...

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1965 Ford Mustang fastback 2+2 A Code 289 C4 Trac-Lok Vintage Burgundy w/Black Standard Interior Vintage 40 Wheels 16X8" w/BF Goodrich Comp T/A Radial 225/50ZR16

I've read the web sites on replacing leaky cowl parts, but I am not sure I understand why you wouldn't just seal the cowl up solid. What purpose is there in allowing water to run in there?

Thomas

The purpose is not to let water in. The purpose is to let fresh AIR into the cabin. The cowl is designed stop the water from entering the cabin by allowing it to enter the cowl and bleed off through drain ports on the sides (inside the fender) before it gets deep enough to rise above the overflow pipes and drain into the cabin.

Generally, debris collects inside the cowl when the vehicle is left sitting along a tree lined street, especially with trees having very small leaves or pine needles. One inside, the block the drain ports, and if they don't do that, they at least hold moisture which leads to rust, or both) which leads to holes which allow the water to flow in.

Even if you were to seal the cowl, if there is already damage, it has to be repaired, otherwise it will continue to expand.

The cowl opening could be eliminated and some alternate form for fresh air induction installed, but I think that would be a lot of work for little return.

There are "cowl covers" available from most Mustang parts vendors (around $35) made of plexiglass/lexan which seal the cowl. This stops the fresh air from entering unless you open the windows, and it's obvious that there are times when you do not want the windows open. Many later model Mustangs had wire mesh screens which kept out the debris.

The covers come in two forms, one is magnetic and the other uses locking screws. Magnetic is fine for when the car is sitting, but I would suggest the locking screw type for driving. From what I have seen, the covers are solid. It would seem that if they were drilled with umpteen small holes, it would allow for the fresh air exchange while still keeping out the debris.

If I had to have the cowl repaired, I would c>>

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1965 Ford Mustang fastback 2+2 A Code 289 C4 Trac-Lok Vintage Burgundy w/Black Standard Interior Vintage 40 Wheels 16X8" w/BF Goodrich Comp T/A Radial 225/50ZR16

Ah, I see. So if someone were to install an AC in a Mustang and seal the cowl off, would that be a bad thing? What I mean is, would you be able to make it only recirculate the inside air instead of drawing fresh air from the outside?

Thomas

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1965 Ford Mustang fastback 2+2 A Code 289 C4 Trac-Lok Vintage Burgundy w/Black Standard Interior Vintage 40 Wheels 16X8" w/BF Goodrich Comp T/A Radial 225/50ZR16