4 Wheel Brakes Locked

Hi
Sorry about my english i will try to do the best.

I own a 2017 Tacoma TRD PRO
Some days ago the brakes locked, after releasing the pedal, 4 wheels where still locked. If i release pressure loosing a brake line it will work normal for a couple of minutes. Then it will happen again.

Thanks for you help


Sergio
Coyhaique, Chile

 

I would check all your brake lines to make sure nothing is pinched shut, otherwise its probably something going on with the brake booster/abs system (on the pro its all in one)

 

We tried with another brake booster, same problem... I will check the lines... but it is weird. 4 wheels are locked.

 

Normally I would say its a collapsed brake line, but that happens on just the soft lines and usually on just a single wheel. The fact that all the wheels are doing it leads me to think its not a collapsed soft line, but rather a kinked or pinched hard lines.

 

Trace the path of the brake line, from the brake booster. There shouldn’t be any kind of check valve or restriction because fluid has to flow back to the booster. The only things I can think of that would restrict the flow are the ABS circuit, A-TRAC function or possibly any ‘hill holding’ feature (but that might be a transmission function).

Try pulling the fuse for the ABS or for A-TRAC. If the problem goes away, you may have an ‘electrical’ related issue. Maybe the ABS modulator. If the problem persists, more likely a mechanical / physical issue.

I’m not familiar with the TRD Pro, so others might have better advice. But if it takes a few minutes to repeat the failure, that sounds like the truck is trying to do something it shouldn't, like applying the brakes for you.

Hope this helps with the problem solving. Mucha surete!