Rust problems on extended cab trucks

I've started to get rust on the cab corner section of the drivers side rocker on my 1995 extended cab Chevy truck. I thought it was from stone chips taking off the paint. I was looking at the rusty spot, and
it is right under the side window. I checked the window and found the seal to be loose. Could the window be leaking, and letting water into the back side of the metal? Would this cause the rocker to rust out, or is it more than likely just rocks chipping away the paint?
Steve
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X wrote:

My '91 has rusted through, from the inside out, on both sides.
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Retiredff wrote:

the doors and corners, then the floor pan rusted. Then the gas tank rusted, then the radiator.
POR-15 is something that I have turned up when I searched for rustproofing. As soon as I pay off the loan on my 2000 I'm going to start disassembeling one part at a time and painting it.
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yup, POR-15 is good stuff. After you get your cab corners replaced, remove your storage buckets in the ext. cab interior and just pour some along each side. Be careful, though, because it's pretty expensive!
Snowman

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If you look around, you will notice that the majority of Chevy extended cabs rust in the same places..
-- History is only the past if we choose to do nothing about it..

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