The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post - The 1978 Sierra Build

Barbecue · 11-04-2015, 07:46 PM

Good looking truck. I'll look forward to seeing more pictures and progress.

Regarding the leak (water on floor), I finally found the cause of my similar issue a couple of weeks ago after months of no success - the windshield seal is leaking at the top of the windshield. To test the windshield seal, remove all interior trim around the windshield, spray the outside with soapy water, then use a leaf blower from inside to force a whack load of pressure on the inside of the seal - you'll get bubbles on the exterior where any leaks are present.

I know there are many other causes of leaks, but that's my experience. Other things to check are the floor vents, if you've got them, and inside the cowl.

11-04-2015, 07:46 PM	#2
Barbecue Registered User Join Date: Jul 2014 Location: British Columbia Posts: 84	Re: The 1978 Sierra Build - I NEED YOUR HELP Good looking truck. I'll look forward to seeing more pictures and progress. Regarding the leak (water on floor), I finally found the cause of my similar issue a couple of weeks ago after months of no success - the windshield seal is leaking at the top of the windshield. To test the windshield seal, remove all interior trim around the windshield, spray the outside with soapy water, then use a leaf blower from inside to force a whack load of pressure on the inside of the seal - you'll get bubbles on the exterior where any leaks are present. I know there are many other causes of leaks, but that's my experience. Other things to check are the floor vents, if you've got them, and inside the cowl.