My brakes have been kind of weak on my 96 Blazer and ive been losing fluid slowly, after looking around the master cylinder and running along the brake lines i found that the line that branches off to my rear driverside brake drum has rusted through and broken. it looks like a 1/8" or 3/16" line that goes directly into the drum. Ive only had this blazer for 10 months & im not familar with drum brakes. so my questions are:

Why cant i find these lines to purchase online? (i think i heard they have to be made?)
Where can i find a diagram of the brake lines for reference?

This is my first post, im very pleased to have found his site, its been a huge help to me. I hope someone can help me, and i can do the same in the future. Thanks!

 

The lines typically are custom made. A few shops make laser guided replacement lines but I have not found them for your generation Blazer. This can be a big repair, I replaced my lines on a 99 Bravada and it was a lot of work. If you can't do the work yourself shop around for an experienced mechanic who will do it right and/ or retrofit it right. Lots of guys that may try and fix it, but brakes are unforgiving. If you have rot in one spot, other spots likely about to give out also.

One note- Autozone sells a copper/nickel replacement brake line that is much more corrossion resistant and super easy to bend when compared to steel lines.

Good luck.

 

I just did both rear lines on my 1997 Blazer. Your 1996 should be the same.

Measure the length of the line, from where it branches from the brake hose junction near the center of the axle, to where it attaches to the wheel cylinder. Take all bends into account. The line is a 3/16" SAE thread, inverted flare line. You can buy the straight length of line at most auto parts stores, already flared with the fittings. To install, just bend the new line to the shape of the old one and install to junction & wheel cylinder. After that, bleed the brakes at all 4 wheels.

I recommend replacing both rear lines at the same time, or you'll probably blow the other line soon enough (if it's really rusty).

You can order the factory-style pre-bent brake lines from a few places online, but it's much more expensive than just buying a pre-flared line and bending it yourself.

 

Whatever you do, don't let the master cylinder run dry and get air in the antilock brake system.

My son's friend let his Mustang's brake fluid get too low and he had to have it towed to the Ford dealership to have the brake system refilled and bled. He went through a couple of pints of brake fluid trying to bleed them himself but never got it right.

 

Oh, man, yeah. Definitely don't let that happen. Some ABS units don't have bleeders on them, and require an OBD-style tool to electronically actuate the unit in order to bleed air out. (I know my 98 Camaro is like this...can't remember if the Blazer is the same way).

As long as you haven't run the master cylinder dry while driving the truck around like that, you should be okay during the brake line installation as long as you leave the rear end of the vehicle jacked higher than the front end during the repair. And, of course, do not let the master cylinder run dry while bleeding the brakes.

 

I spoke to my mechanic & he said he'd have to fit them. Thanks for the info as to what size/type of line to buy, everything was very helpful... Us there a site though that has a downloadable repair manual that had wiring & other diagrams for blazers or do I have to buy the book from the auto parts store? I'd like to find some kind of reference material to keep handy since my friend (who's a mechanic) & I do most the work on it...any suggestions?

 

If you buy a manual at a store, buy the HAYNES manual, not the CHILTON'S one. I bought the Chilton's manual and have completely hated it. It is the only repair manual I have ever bought that has been absolutely no help when I need to know how to get a job done. I find more useful into online. I'm not exaggerating here. Haynes isn't exactly perfect, but seems to be better than the generalized, hands-off quality that Chilton's is dumping out these days.

Best bet is to try to download or find a GM service and/or factory build manual for your Blazer.

That's my opinion.

 

Most manuals including the factory does a poor job of showing the lines in which they call pipes. I am assuming your rear brake pipes are not your primary concern, but the pipe from the master cylinder that runs to the back as being the problem. That pipe rots real quickly because salt gets thrown up along the left side of the frame, and with the gas take placement, has no place to exit and it sits on top of the steel pipe and corrodes the pipe. If your mechanic needs a diagram of the pipe- he may not be fluent in the way GM installed these pipes at the factory. I replaced mine and it was a pain- but it was doable.