Guys,

This time, it's the Avalanche. Yup. the one we just replaced and intend to sell....

So, late last summer, I noticed the truck would swerve to the left upon applying the brakes. At first I thought it was the boat trailer, because I had to replace the master cylinder on the trailer, and I typically have doubts on my own repairs, but pretty quickly figured out it was doing it while not towing. I then discovered a bad axle seal on the right rear wheel. It was slinging gear oil onto the brake disk. So I fixed that. Still swerving on braking.

Then, on Saturday, The wife and I took it out for a bit, just to keep it up a bit. As we neared home, after a relatively short out-n-back, we started smelling hot brakes at each stop. When we got to the house, smoke was POURING from the right front wheel hub and the smell of brakes was REALLY strong. I jacked it up, got the wheel off, and discovered the rotor was blue and the wheel was locked up. I set up a fan blowing on it and, after it cooled off, it was free again, but you could definitely see where the brake pads were on the rotor when we came to our final stop. While I could turn the hub, the brakes were obviously dragging, especially at a tight spot, which is very likely the cause for the excessive heat. After talking with a couple of shops, I was fairly confident it was the front brake lines, so I set to replacing them. After disconnecting the brake line from the right front caliper, I decided to test the flow. I staged my phone to take a video (I was alone), started the truck and pushed the brake pedal to the floor. There was SOME resistance, but not much. The video showed what I would consider plenty of fluid pumped out of the brake line. I also compressed the caliper cylinders while the brake line was disconnected, and fluid flowed freely out of the port. It would appear that fluid has free passage everywhere it needs to go, and the caliper pistons are mechanically free. The brake pads easily slip in their nests, so it doesn't appear they are hanging up, and the spreader springs seem to have plenty of action to do their job. The only thing I can't confirm is fluid flow back to the master cylinder and'or ABS pump assembly upon release of the pedal. There is no ABS light on the dash, which I'm told is an indicator the ABS pump assembly is working properly. With all this confirmation of free-flowing brake fluid, I decided not to go to the effort of replacing the brake lines yet. We still need to bleed the brakes, since I pretty much emptied the right caliper, and then I will take it back out on the road for a bit. For the record, unless blowing a bunch of fluid through the brake line might have miraculously done the trick, I really don't expect a disassembly/reassembly/bleeding to have fixed the issue. These are new calipers, rotors and pads on the front, as of this spring, FWIW.

The behavior seems to have come on fairly slowly. It seems like the brakes on the right are slow to grab, causing the swerve to the left, then even out, and then don't release sufficiently, or even not hardly at all, when the pedal is lifted. Do we have SOME flow to the right side, but not nearly enough? Or are we looking at a bad ABS pump assembly that is somehow not throwing a code?

While the shop is offering to put us on their schedule, since we are looking to sell the truck to help fund the wife's mid-life crisis car, I don't want to pour a bunch into just getting it back to sellable if I can help it. I can do most of the work, but don't want to just start throwing parts at it until it goes away. With all this said, anybody have any clue what might be the culprit? Or should I just grunt through replacing the brake lines and see if that's what it is?

Thanks. Brad.

Why did they say brake lines are making the brakes sticking on? Sounds like when you let up the fluid is not bleeding back into the system (causing the brakes to drag) but I am at a loss why brakes lines would cause that? ABS pump/ Master Cylinder, things like that could but the lines?

But who knows if there is something new they do with the lines.

You will need to get the brakes to act up again, once they're acting up loosen up the brake line where the metal brake line connects to the rubber brake hose, try spinning the rotor, if it doesn't spin loosen up the brake bleeder, try spinning the rotor , if it spins replace the rubber brake hose

brake lines fail all the time. fluid will go into the caliper but not return until it sits and slowly bleeds off. hoses are cheap so just replace them. other issue is the caliper will stick on the pins and not slide correctly. it will cause them to delay pushing on the rotor and then let them drag until they relax. if it was that hot just replace the hose, rotor and caliper.

Don't blindly trust a new caliper. Reman quality has gone in the ****ter on brake parts especially. I had a nasty crash in my road race car due to a reman caliper's banjo bolt threads failing.

If you've already gone so far as to remove the brake hose at the caliper I'd replace the caliper. You should still have a warranty for it. Just take it back in and tell them it's sticking.

I recently put rear brakes on my Florida garage kept 2012 Escalade at 50 thousand. I c-clamped the pistons back in just like the other 20 brake jobs I've done in my life time, once I pumped the pedal and took it for a ride it smoked the new pads and original rotors.
I surmise the factory calipers had poor quality pistons in them that easily corroded and once pushed back in would scar and not return .
New calipers and not a problem as I originally suspected the brake lines after reading of similar problems.

Been there, done that. I'd bet the caliper pins are rusty with no grease left on them.

Guys,

Problem solved. I replaced the brake hoses from the hard lines to the calipers. No more swerving. No more dragging. No more excessive heat. No more smoke.

I cut the hose from more problematic side into 1" sections, trying to find a restriction, but I didn't find that first spot that was any narrower than the ID of the inlet/outlet fittings. The only thing I can think of is that, when the brake pedal was released, it collapsed the hose to the point it wouldn't allow the fluid to evacuate the caliper. This is what both shops I spoke to suggested would be the case.

And here I thought all brake line failures were pressure related......

Thanks. Brad.