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Hey all, trying to trace a few leaks into the cab.
1. Have a leak that is near the brake release. It appears to drip down from up near the wiper switches. I cannot see any water stains or traces that are up under the dash.
2. Also have a leak that comes from the passenger firewall. I think the gasket around the havc is seeping.
3. Is there supposed to be a seal between the hood and engine bay? I was looking at the blow out diagrams and i think i saw a seal there but wasn't called out.
The seal you mention is a "cowl seal" or "cowl lacing" available from a couple of sources. One member on here donated one to SteeleRubber for a template.
They are now available on their website. I got mine from Rubber the Right way on either ebay or amazon.
As far as the leak near the parking brake pedal, so do I. I haven't been able to pin down the source either.
If you find yours, post it up and I'll do the same.
I know mine leaks where the firewall comes down and meets the toe-board. If that particular pinch-weld gets disturbed, it will crack the dried up >40 year old seam sealer, and cause a leak. I've got my leak almost stopped, but in a real heavy rain, some will still get in there.
Try shining a bright light on the outside of the firewall, and see if you see any light coming through, inside the cab.
Plus, my cab came from a truck with more options than mine, so there are more small round holes in the firewall than the old cab had.
The seal you mention is a "cowl seal" or "cowl lacing" available from a couple of sources. One member on here donated one to SteeleRubber for a template.
They are now available on their website. I got mine from Rubber the Right way on either ebay or amazon.
As far as the leak near the parking brake pedal, so do I. I haven't been able to pin down the source either.
If you find yours, post it up and I'll do the same.
It has to be the second most annoying leak. It only leaks when it sits outside with lighter consistent rain. The drip point is about 3ish inch from the floor highbeam switch.
I know its not from why windshield as i just replaced the rubber and glass. I thought that fixed it but hey replaced it in the dry season. Lol
X2 on checking the cowl vent drain holes. They get clogged up with leaves and twigs and will allow water to run through the vents onto the toeboards since they can't drain fast enough when clogged.
The cowl seal "shouldn't" affect the interior. I would check the cowl drains on the body inside the front of the doors.
The hood seal can definitely affect the interior. The water runs down and hits the seam where the firewall meets the floor pan. The seam sealer almost always has a failure somewhere along this seam and water creeps between them. Also, on an ac truck, the water runs down the ac box and comes in at the blend door hinge, runs through the box and into the cab or out the ac drain. Water also follows wiring between the wires and the casing, which it will come out anywhere.
Aside from making sure that the whole cowl is clear of debris, a hood seal of any design is prudent to help eliminate leaks.
One thing to note: Most people forget to take care of their rain gutters above the door. Since I mentioned seam sealer before, the sealer in the gutters shrinks and cracks, leaving voids for water infiltration. This, along with window seals, hood seal and clogged cowl, is one of the most leading contributors to cab rot.
I've done some searches on here for related issues and have seen that the wiper pivot seals is a possible source of leaks as well.
My question is, that when I look up the seals, every supplier lists 4 seals per truck. Does one go outside the cab and the other inside? If one is required outside, how the heck do you get it in there with the cowl area being inaccessible?
I did watch an Autorestomod episode for a 72? and it only showed seals inside the cab. (2 total)
The 73-79 attach in the same manner. I dont know if they sell seals specifically for those but, I would probably make my own. Either out of inner tube(least preferred) or some 1/8" rubberized gasket type material from the local Auto hut or a hardware store. I would make sure to do it as a one-piece design. You also have the option to use an RTV of sorts, but that is sloppy and essentially glues em in.
Well after getting the fender off, I found that the seam in the upper center of the first picture is inaccessible. I think the water is actually getting there by running down the front seam inside the cowl which is also inaccessible.
I'm gonna clean and protect the area as best I can and maybe come up with a solution after a nights sleep. Maybe some sealant on the screws????
Been thinking that new wierd seals ought to be easily made by making a form from something like balsa wood, putting it in a pan with a bit of weight on top, and filling the balance of the pan with the required depth of FlexSeal. Cut and trim the resultant after it dries, and voila. Too much of a pain for obtainable seals, but for that unobtanium type, ?
