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Brake line replacement

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I just joined this forum to post up in this thread - http://www.gm-trucks.com/forums/topic/154899-brake-line-size/- only to go to the main forum page and find an ever longer thread on brake line replacement! No surprise there.


After reading through this I also plan to file an NHTSA complaint. I was fortunate that it was a shock replacement job that finally ruptured one of my severely corroded lines - so I wasn't on the road when it happened.


Here is what I wrote in the other thread:


I know this is an old thread - but it is one worth digging up since it deals with the notorious brake line rust that troubles most GMT-800 body trucks.

About to tackle replacing the hard brake line that runs from the ABS module to the splitter at the rear of the truck feeding the two calipers. I joined this forum just to say thank you, particularly to brucelimerick, for all of the information posted about this job.

Basically, my background story is that I bought a higher mileage (163,XXX) Z71 Suburban (2003) on Craigslist for below market price - the guy was just trying to get out of his loan payment. The body was clean and the interior in decent shape, but it had clearly been neglected. The suspension was original (shocks and everything) from the factory, and the underside has significant surface rust (not frame damage though) as the vehicle started its life in Michigan (I am in Virginia).

I have been working through the vehicle, updating and replacing parts as needed, and it is shaping up to be a pretty decent car. I am still questioning whether or not I would buy another GM vehicle, as I have experienced now two inexcusable design failures - the transfer case pump rub issue (causes pin-sized holes in the t-case), and now the rusted to hell brake lines.

**End rant**

The other weekend I replaced all of my shocks and put new coil springs in the rear of the truck. Of course, after letting the axle droop I now have a brake line leak in the long line running from the ABS module to the rear splitter.

Thanks to this forum I have already purchased EasyBend brake line (copper nickel) and a double flare tool - I plan to cut out the old line at the ABS module and the splitter, but otherwise leave the old line in place and simply bend into place a replacement line which I will secure to the existing line.

I appreciate all of the information here - particularly on the fitting size/line sizes. I also have a Motive Speed Bleeder so hopefully that will help with the process. The only concerns I have about the job are creating my own flares, and tightening the new line to the ABS module where there is hardly any place to fit a wrench. Will post up how it goes for anyone else who might be up for tackling this job. After realizing how expensive it would be to have a shop do this job, I decided to tackle it myself even though I have never replaced a hard brake line before.

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  • 11 months later...
  • 3 months later...

I was changing my oil in my 2004 Chevrolet Suburban and I noticed fluid on the frame under the area where the master brake cylinder is. Checked my brake fluid reservoir. It was almost empty. Filled it up and took to the dealer thinking it was a leaking master cylinder. Turned out all of my brake lines had corroded and were leaking. What a safety issue. To top it off my fuel lines were also corroded. Total cost to replace all of these was over $3,300. It only has about 100K miles on it. Never had a car have a failure like this. Plan on reporting it to NHTSA. Apparently this is wide spread. They need a recall if they put such crap lines on the vehicle.

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  • 2 years later...

I have a 2006 Silverado crew cab 6.0. Blew a rusted brake line. Have tried everything to get that line unscrewed from the place by caliper.  Its seized and wont unscrew. Last thing I tried was to put a torch on it and try to unscrew it. The thing wont unscrew. It acts like its going to mess up the threads. How is it that I get it off? Can I replace the whole thing its on?? Put wd40 and seized and rusted spray on it and still not coming lose. I need this resolved in one day. I am losing time. 

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  • 1 month later...

The pre-bent brake lines are available from GM as a kit for about 300 bucks, they're coated now, but for the same price, in line tube gets you stainless steel pre-bent lines. Mind you they are a bear to change, very time intensive, figure 8 hours before you drive away, our shop has done many of these jobs, if your not mechanically savy, don't try it, let someone with experience do it, and even then, it's a nasty job on these pickups and suburbans loaded with rust. I was told by a Chevy parts guy that GM made these parts available because they were expecting a recall, but that never happened, makes sense to me considering that many other parts for these 2000-2008 vehicles are already obsolete from the dealer

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