We have one of these trucks.
I replaced the brake lines last year - all of them. Ginormous PITA, would have cost a fortune to have a mechanic do them.
I also relocated the ABS controller to an area less subject to corrosion. Found out later that GM relocated it on later model trucks to almost the exact same spot.
This was my first newish truck. Had no idea how stupid the design of the bedsides are - almost guaranteed to corrode over time. Ours went from beautiful to completely rusted through in less than a year. Of course, this isn’t just a GM problem.
The frame also rusted from the inside out in several places. Had to weld in several patches.
Worst was the rocker panels - completely eaten away as if by cancer from the inside out. I don’t know how I could have prevented this had I known it was a problem.
Now, I don’t expect vehicles to last forever, but for what GM wants (and wanted) for a new truck like we have (4x4, V8, automatic, extended cab) I expect it to be made of better materials and design. It’s not like the truck was worked hard - it’s basically a commuter vehicle.
Then there’s the failed heater control modules, the failed 4x4 modules, the multiple revisions of the steering intermediate shaft, the multiple revisions of the driveshaft yoke, ABS problems requiring replacing the front hubs, ABS problems requiring replacing the ABS module, heater cores that rust out and require the entire dashboard to be removed to replace, multiple emissions modules that fail, failing fuel level senders, gas tank straps that corrode away, door hinges that wear and cannot be replaced, multiple revisions of door latches, dash bulbs that are soldered and can’t be replaced when they burn out. And the multiple part revisions are nice - except when they all get released after the vehicle is out of warranty. I could go on, but I won’t.
IMHO, out of ignorance or on purpose, this vehicle was designed to self destruct. I mean, GM’s been making pickups for most of 100 years. Yet they don’t seem to have learned anything.
We also have an 87 Ranger with almost the exact same body rust issues. Except is has 13 more years on it before the same problems emerged.
In any event, there’s not much I can do. The truck is worthless as a trade, and GM has lost a customer forever. I’ll continue to keep it on the road as long as I can because I have to, but I won’t make the mistake again of paying GM for the privilege.
In my view this is something that GM should own. It costs a bundle to have these lines replaced by GM or an auto repair business.
These are rusting through in 6 to 7 years in a lot of cases, they are using cheap rust proofing and was not locating properly as you discovered.
Typical trip to the parts store for a GM vehicle:
Customer: I need a (fill in the blank) for a 20XX Chevy XXXXXX, 5.0 liter V8 with power steering and A/C.
Parts department counterman: Two or four wheel drive?
Cust: Two wheel drive.
PDCM: Regular or extended cab?
C: Extended cab.
PDCM: Towing package?
C: I dunno. I'll have to check.
Later
C: OK, it has the towing package, I think.
PDCM: Does it have self leveling?
C: I dunno. Let me check.
Later
C: No, it doesn't have that.
Was it built in the U.S. or Canada?
C: Sh!t, I don't know.
PDCM: What's the VIN number?
C (getting slightly irritated): I'll have to check.
Later
OK, the VIN number is XXXXXXXXXXXXX.
PDCM: OK. What's the build date?
C (getting highly irritated): Hell, I don't know! How do I find out?
PDCM: Check the door sticker.
C: OK, I'll be right back.
Later
C: It says ten, twenty-three, oh three.
PDCM: Morning or afternoon?