My RAV 4 has a loose parking brake

I drive a 2011 (Toyota) RAV4. The other day I went to a friend’s house that has a steep driveway, so I put my parking brake on. When I went to leave, the handle went back down, but it didn’t spring back the same way it usually does. It feels kind of loose now. Everything else seems normal. My brakes work fine. What do you think has happened? Brake Broke on the Mountain

Sometimes called the “emergency brake,” the parking brake is a feature of every light duty car and truck. With the overwhelming majority of today’s vehicles having an automatic transmission, and all but an exceedingly small number of those having a “Park” position, which mechanically locks drive to the wheels, you’d wonder why automakers bother to include a parking brake at all.

They do, in part, because it’s required by law. By definition, the parking brake has to be a mechanical way of leaving brakes applied in such a way as to prevent the vehicle from rolling on a grade, even if left in Neutral.

Your instinct to apply the brake on your friend’s driveway was correct; even an automatic vehicle benefits from having the parking brake doing the work of holding it on any kind of slope. The pawl (lever that engages with a cog) mechanism inside the transmission that locks it isn’t meant for that task, although it is out of necessity designed to be able to do it. If you’ve ever pulled an older car out of Park on any sort of appreciable incline when the brake hadn’t been applied, you’ve experienced the increased effort and heard the loud “clunk!” that doubtless occurred as the pawl released.

A lot of newer models have switched to an electrically operated parking brake. In the vast majority of these, electric motors are mounted on and directly apply the rear brake calipers.

In the few electric brakes that aren’t integral, and in virtually all other cases, the foot pedal or hand lever pulls on the cables. These can go to the rear calipers and directly apply/hold them on, or they can go to the shoes inside a drum-type brake, accomplishing the same job.

Even on a model that has fourwheel disc brakes, it’s quite common for there to be a small drum brake inside the rear brake rotor, separate from the service brakes. Most pickups and many cars and crossovers, including your RAV4, use this design, known as “drumin-hat.”

Here’s where this is relevant to your Toyota: Because this type is completely independent from the regular brakes, it won’t affect their feel or function.

Unless it’s staying applied enough to cause resistance or make noise, there’s little to indicate an issue beyond ineffectiveness or the weird lack of tension in the handle (or pedal).

Most likely, either one or more of the cables, or the mechanism in the parking brake on either (or both) side(s) is partially seized.

Using the lever, your arm can overcome the resistance this creates, but releasing it fully relies on some small springs in the rear brakes that simply don’t have that much oomph.

The rear brakes will have to be disassembled to determine what’s gone wrong, and to repair it.

Seized parking brakes are much more common in vehicles where they’re not used regularly, as they should be. As I advise my customers, use it every time, or never use it at all.

ASK A MECHANIC IS WRITTEN BY BRIAN EARLY, A RED SEAL-CERTIFIED AUTOMOTIVE TECHNICIAN. YOU CAN SEND YOUR QUESTIONS TO

WHEELS@THESTAR.CA. THESE ANSWERS ARE FOR INFORMATIONAL PURPOSES ONLY. PLEASE CONSULT A CERTIFIED MECHANIC BEFORE HAVING ANY WORK DONE TO YOUR VEHICLE.