Truck issue: Brakes locking on Chev Blazer

Hey mechanically-minded people! If anyone has any suggestions to help solve this problem, it’s greatly appreciated.

We have a 2002 Chevy Blazer. Just recently the brakes started locking on us. Since we just had our brakes replaced a month ago, I took the truck back in today to talk to the mechanic about it.

He’s stumped. Of course the truck wasn’t cooperating to demonstrate the problem so they took a look at the brake pads and didn’t find anything other than hot spots.

His suggestions were:

[li]The master cylinder[/li][li]The anti-lock brake system [/li][li]The wolverines in the trunk. (Well, not really but two items doesn’t seem like much of a list.)[/li][/ul]

He feels that replacing the master cylinder would be the best place to start but at $200 I wanted to check here and see if there are any other avenues we should pursue before we open the wallet.


More specifics, please.

  1. Define locking, please. Do you mean having a greater propensity to lock up under heavy braking (which ABS should prevent) or brakes sticking to the discs/drums while the vehicle is parked? All four wheels or just one axle?

  2. What was replaced? The brake pads? Calipers?

  3. Hi Opal! (This is what we do on SDMB to pad a two item list.)

Your mechanic didn’t even look at the calipers?

Don’t ask me how I know this, and it’s purely hypothetical of course. If you were to replace the pads on your wife’s 1997 Ford Explorer and then accidentily twist the brake hose when putting the front right caliper back on in such a manner that you couldn’t easily tell until you took the tire off (remember, this is hypothetical) you would probably hear pretty quickly from your wife that the brakes were locking and pulling to the right.

You could of course dismiss her claims immediately to those of a delusional non-mechanical wife.

Until, of course, your delusional and mechanical self took the truck for a spin. Then, I would find crow to go best with a side of corn.

Another vote for caliper trouble.

BTW… Front or back?

Is there really bad vibration/shudder while braking or full on lock-up?

NurseCarmen said to look at the brake hoses, good start but there are some problems that are not visable. A hose can breakdown internaly and act as a “check valve” allowing high pressure fluid in to the caliper, but not out. That would keep the brakes on.

Raise car and remove tire.
Turn rotor and check for drag.
If there is drag, open bleeder and recheck.
If the drag lessens, replace the hoses.

Let us know what happens

  1. The first time it happened to me was after driving the truck for a bit I stopped to go to the store. When I started it up again, the brakes were locked. The other time was when we were in a stop/start situation at a border crossing and they locked for a bit.

Since all the brake pads had hot spots, I assume all four are locking.

  1. Are you referring to the actual brake job we had previous? All four brake pads were replaced, that was it. We haven’t done anything since.

  2. Yeah, I just wanted to be different.
    There isn’t any shuddering at all. The best way I can describe the sensation is resistance. No pulling to either side.

Ok, I’ll add calipers and hoses to the check list. I’m really glad that this has happened when my husband was driving because I’m usually the “delusional non-mechanical wife”. :slight_smile:


Hot spots on the pads are a symptom, not a cause. Replacing the pads accomplished zilch. Sticky calipers is the most common cause of locked brakes. If your truck is out of warranty, rebuilt calipers are not a terribly expensive item to have installed (>$30 each on my 1994 C1500 from the local NAPA warehouse, last time I checked). Of course, checking the lines for kinks or obstructions is the first order of business and should have also been done when the pads were replaced.