Rain Water Leak in Channel below heater box
11-28-2017, 08:08 AM
#1
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Rain Water Leak in Channel below heater box
Hi all, I have a 1982 V6 Berlinetta, have been trying for a year or more to seal a water leak that appears to be under the heater box, original hole was dime sized, fixed that, but rain still gets into car when there is a heavy rain storm. It may be in horizontal channel that runs below heater box to center of firewall. Impossible to get to channel under heater box. Is there any product that I can pour down that is thick enough to seal the channel?
11-28-2017, 08:41 AM
#2
Supreme Member
Re: Rain Water Leak in Channel below heater box
My car had this problem after attempts to repair visible issues in the cowl/firewall area.
Here’s what I did, and which seems to have greatly reduced my firewall leaks:
Rinse cowl with water from garden hose until drains on both sides run clear.
Allow to dry.
Put catch-buckets under the downspouts on each side, and pour acetone into cowl drain. Acetone will reduce any oily buildup that may be present.
Use powerful LEAF BLOWER to force acetone through cowl drains.
Allow to dry.
Buy one gallon of Rustoleum paint.
Pour paint into cowl bowl at rate of about one pint at a time.
Use powerful LEAF BLOWER to force paint through cowl drains.
If you have access to view under/behind dash, you may see paint weeping through cracks/pinholes in firewall.
Allow sufficient time for seeping paint to firm up between applications.
Eventually, through repeated cycles of paint/blower, the paint will seal the small cracks and pinholes.
You may need to re-apply if leaks persist.
This is not a “professional” repair.
If you want professional, strip every part off the body, and mount it on a rotisserie.
If you want reasonably effective, and affordable for a non-Concours car, my method works.
After more than a year, I’ve only had one leak from the firewall area. Small puddle about half the size of a dollar bill after 3 day’s rain. I can easily see evidence of any leak, as my car has bare painted floorboards.
While you are hunting water leaks, make sure the areas between the drip rails and the roof metal are intact. If you can stick a thin screwdriver just under the drip rail, and dislodge rust chips, you have a problem there too.
Here’s what I did, and which seems to have greatly reduced my firewall leaks:
Rinse cowl with water from garden hose until drains on both sides run clear.
Allow to dry.
Put catch-buckets under the downspouts on each side, and pour acetone into cowl drain. Acetone will reduce any oily buildup that may be present.
Use powerful LEAF BLOWER to force acetone through cowl drains.
Allow to dry.
Buy one gallon of Rustoleum paint.
Pour paint into cowl bowl at rate of about one pint at a time.
Use powerful LEAF BLOWER to force paint through cowl drains.
If you have access to view under/behind dash, you may see paint weeping through cracks/pinholes in firewall.
Allow sufficient time for seeping paint to firm up between applications.
Eventually, through repeated cycles of paint/blower, the paint will seal the small cracks and pinholes.
You may need to re-apply if leaks persist.
This is not a “professional” repair.
If you want professional, strip every part off the body, and mount it on a rotisserie.
If you want reasonably effective, and affordable for a non-Concours car, my method works.
After more than a year, I’ve only had one leak from the firewall area. Small puddle about half the size of a dollar bill after 3 day’s rain. I can easily see evidence of any leak, as my car has bare painted floorboards.
While you are hunting water leaks, make sure the areas between the drip rails and the roof metal are intact. If you can stick a thin screwdriver just under the drip rail, and dislodge rust chips, you have a problem there too.
Last edited by W.E.G.; 11-28-2017 at 08:45 AM.