Occasional Brake Grabbing/Dragging

Maintenance/Repairs
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First time listener & caller but I’m in a pickle so please let me sing you the song of our 2014 Buick Enclave:

It’s been a great car. That said, twice in the last two weeks the following has happened to my wife: the car seemed normal, she was parked or stopped, she tried to move and our Enclave was stuck. The (front) brakes seemed to be engaged. The first time it happened, she was driving up a small hill and stopped at a stop sign, only to find out that she couldn’t get moving again. At least without significant power. She applied power, smelled brakes and wound up running out of fuel trying to get to our car guys. Had the car towed to the shop. No codes. No theories.

It happened again last Thursday evening (President’s Weekend) but resolved itself… magically, quickly [or something]. We were headed on a weekend trip and I was adamant that we not drive with brake issues. Given the infrequency of the issue and the fact that it seemed to clear itself up, I relented, we were unlikely to get stuck, etc, and we drove the car to Western MA. All was fine.

Sunday morning in Western MA: I warmed up the car and backed it out of three family vacation home rental’s driveway/parking-space; then drove a bit forward to point the car towards the driveway exit (so that everyone could load their gear and person into the car and we could haul ass to the slopes). Bags were loaded. Wife and kids loaded up. I put the car in drive, applied a bit of power and the car did nothing but rock back-forth over its wheels (maybe an inch of forward movement). Switched back to park, turned the car off, turned it on, back to drive, power, etc, once or twice and nothing. I think the brake pedal may not have been raising during this period. Turned the car off, then on, left it in park as the chaos of 3 families on vacation together in crisis swirled around me.

Relocate my wife and kids to other families’ cars. Much time spent discussing logistics, are you okay?, etc. Fine. I’ll just take the car to a service center which is open on Sunday and meet y’all wherever. They pull out of the driveway; I put the car in drive, took my foot off of the brake and followed them . A storm of WTF text messages followed (before I turned off to head to the brake shop).

I went to the highly recommended, and open on Sundays, Monro Muffler and Brake of Pittsfield, MA. Great folks, but no codes and no hypotheses. And thankfully no willingness to spend my money on wild goose chases. Technician even commented on the great feel of the brake pedal.

Drove 3 hours home to NJ the next day. All was fine.

Wife took the car to a Buick dealer today. They inspected it. They drove it. Clean bill of health.

If Click-and-Clack were still on, I’d call in. But they aren’t, so I ask you, dear reader, what could possibly cause this issue with our car’s brakes? The best guess of the fellow at Monro was the ABS pump. Other than that, we have no idea (after taking the car to be inspected three times). 1,000 Internet points to whomever posts the best or most creative answer!

Thank you,
CoffeeDregs

2

Remove the fuse ABS MTR.

Buick-enclave-2014-fuse-box-engine-compartment.jpg1062×793 115 KB

If the problem goes away, you know the problem is with the ABS.

Tester

1 Like
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The most probable cause in a case like this would be a sticking piston in the brake master cylinder. This would keep both left and right brake units engaged in either front or rear depending on which piston was sticking. Removing the ABS fuse would only tell you if the pump motor was the culprit but the could also be an intermittently sticking isolation valve in the hydraulic portion of the ABS unit. This would only keep one wheels brake unit engaged. When you say the brakes were smoking can you describe which ones they were? This will help identify the problem.

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There’s several reasons why the brakes might lock up like that. For a clue, suggest to feel all four wheels after a short drive (when that’s possible), see if one of them is much hotter than the other. If so, you’ve isolated the problem to that corner at least. Besides that, and presuming it isn’t an electrical component like the ABS system, and the brake system hydraulic fluid level is ok and the fluid looks clean …

  • Make sure the return spring (if used) on the brake pedal hasn’t come loose.

  • The brake master cylinder could be failing.

  • The brake booster could be failing.

  • A flexible rubber brake hose could be failing.

  • The piston in a brake caliper could be sticking.

  • The brake caliper might be sticking on its slides.

If I had that problem first thing I’d do is test if the brake booster is able to hold vacuum using a hand-held vacuum pump.

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@Tester One of the shops we took the car to mentioned that it might be ABS. I’ll find that fuse and pull it if/when the problem re-occurs. Thanks. I also liked your answer over in Sticking Front Brakes :

“Over time these hoses can deteriorate internally where a hunk of rubber delaminates and hangs inside the brake hose. This hunk of rubber can act as a check valve. That is, when you apply the brakes the pads clamp the rotors. But when you release the brakes, that hunk of rubber prevents the hydraulic pressure from releasing the caliper pistons. So the brakes remain applied.”

@It_s_Just_Me My wife did not recall which brakes were hot. She just mentioned that she could smell hot brakes. “sticking piston in the brake master cylinder”: sounds about right. Strange that it’s so intermittent. Hasn’t happened again since last Sunday.

@George_San_Jose1 “first thing I’d do is test if the brake booster is able to hold vacuum”: would this be likely to lead to intermittent/occasional failure sticking?

The part that still puzzles me: why does it unstick after a few minutes? It’s not the external temperature; this happened with the car cold/warm in cold/warm temperatures. It’s not at car-start; this has happened after driving the car for a few minutes.

Thanks for your help!

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Possibly, if the leak were a small one. There’s other ways that a brake booster can fail besides a diaphragm leak, but it’s a 5 minute job to test the integrity of the brake booster diaphragm. That’s why I mentioned it should be at the top of the list of things to check.

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Did the ABS or traction control light come on?

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No lights have come on… Frustrating.