Pinhole Heater Hose Leak
by Charlie Snyder
Sonnenflecke
May/June 1999
Sunbelt Chapter BMW CCA
Here's a neat little fix that might help you out sometime. I discovered a small pinhole leak in one of my coolant hoses. As usual, the parts store didn't have the hose on the self, but could obtain one the next day.
While the leak was not a gusher, it did deplete the system enough to light up the low coolant warning and make a mess under the hood. The "fix" consisted of cutting a rubber patch and spreading one side with blue form-a-gasket (i.e. Permatex RTV Blue). After the cooling system temperature subsided, I clamped the patch (gooey side centered over the hole) to the hose with some sturdy twist-ties. Hose clamps would have worked - I just didn't have the right size in my possession at the time. I let it set overnight and drove it the next day without a leak.
The bottom line: if you're in a pinch, this repair might help you out, necessity being the mother of invention.