Anybody know about 2001 GM Truck brakes?

Had a close call last night. I was driving down the freeway on my way home from work, when the car in front of me suddenly stopped. I had about 1k lbs in the bed, and stopped about 6 inches from the car's rear bumper. Got into the anti-locks big time. So we start back up and I check my brakes. Pedal goes to the floor and there is barely any braking. I limp it home, and while the brake light (not anti lock light) didn't come on at first, it did later.
We had a big storm last night and I couldn't get it into my shop, so I haven't actually looked at it yet, but I'm at work and thinking about it. I'm pretty knowledgable about brakes in general, having specialized in them when I was a plier operator, and initially I'm thinking a blown brake line or seal in the master cylinder. But if the brakes are circuited diagonally (are they?), then it should be pulling if I blew a brake line, and it's not. Anyone know any specifics about this vehicle that would help? Or am I just looking at a typical brake system that I just need to trouble-shoot. I guess what I'm asking is if there is anything unique about this brake system that would help explain what happened. To be clear, the brakes worked properly during the emergency stop, but then didn't work the next time I tried them.

I think you blew a line or the master is bad. Those trucks are front to rear, not diagonally....

Just went thru same senario, brakes are split frt to rear. Prob a rotten line near the fuel tank. A real bear to bleed. I bled it out, had a decent pedal, then lost the pedal after a couple of days. I had to cycle the ABS to comepletely bleed the air and keep a good pedal. Hope this helps

as mentioned front/rear not diagonal... had to replace a line for a friend on her suburban... line was pissin fluid from the hard line going to the axle (after it got off the frame and was tucked under/around the spare tire)

thankfully the entire line wasn't rusted so I was able to pull it away from the frame in the wheel well and make a joint there... no way would I have been able to re-run the entire line.

for the '98 astro van I had it rusted between the frame rail and the fuel tank... but only after I killed the front passenger line (and replaced)... in the post bleed "pressure leak test" I guess i put enough pressure to the rear line to kill that line also...

Are rusting brake lines a common problem on this era of GM trucks or are we talking 10 y/o hard lines on any vehicle?

Do they salt the roads in Ohio?

In reply to 914Driver:

Oh yes, very much so in northern Ohio. And it sucks. But my truck has only been in Ohio a year, and wasn't driven much over the winter. It does have some rust on the underside, but it's not that bad. However, I'm thinking a blown brake line is the most likely failure based on how it's acting. I'm going to be out of town the rest of the week, so I won't get to even look at it until at least the weekend. Thanks for all the info, guys. I'll let you know the outcome.

fasted58 wrote: Are rusting brake lines a common problem on this era of GM trucks or are we talking 10 y/o hard lines on any vehicle?

my astro was a MI car most of it's life... my escort was a MI car for 15 years before it moved to FL before it decided to spray fluid...

but that suburban was in WV I believe it was for about 3 or 4 years before making its way down to FL... very little rust... but don't recall if it was rust or what on the line

the GM trucks from that era are starting to be known for blowing the hardline for the rear brakes right under the front of the cab, especially in areas of the country where they use a lot of salt on the roads.

In reply to novaderrik:

Well that's the first place I'll look later today once I get it up on the lift. Thanks.

In reply to bravenrace:

Yup, that was it. There's four lines that run together right there, and the other three didn't look too great either, so I'm replacing all of them. Wonderful.

At least you found it before any major carnage.

Okay, anyone know the trick to getting a pedal on one of these? I've bled and bled and bled, and still no pedal. I'm not getting any air out of the bleeders either at this point.

Gravity bleed it over several minutes....THEN pressure bleed with the pedal.

Funny thing, the problem (again) turned out to be my fancy shmansy pressure bleeder. It's going on Ebay this time.