2004-2007 Subaru Impreza Parking Brake Problems and Adjustment

By Core Brake Parts Tech Team — Circleville, OH warehouse

On a 2004-2007 Subaru Impreza the parking brake is a hand lever and two cables that work a small set of shoes inside a drum built into the hat of each rear rotor. When the lever pulls up too high, the car rolls on a slope, or a rear wheel drags hot, the fix is almost always the same order of work: adjust the shoes at the wheels first, then take up cable slack at the lever, and replace shoes or cables only if adjustment cannot bring it back.

How the Impreza Parking Brake Works

US-market 2004-2007 Imprezas use disc brakes at all four corners; the 2.5i spec sheet lists front and rear disc brakes with four-channel ABS. The rear disc calipers do not hold the car when parked on this generation. Instead Subaru uses a "drum in hat" design: the center section of each rear rotor is machined as a small drum, and a pair of parking brake shoes sits on the backing plate inside it.

When you pull the lever between the seats, a cable runs back to each rear wheel and spreads those shoes against the inside of the drum. A threaded star-wheel adjuster between the shoes sets how close they rest to the drum. Because the shoes only work when the lever is applied and never during normal stops, they wear very slowly, but they do not self-adjust the way service drum brakes do. Clearance creeps open over the years as the lining and the drum surface wear and as the cables stretch.

Two shoe kits cover this generation. Genuine Subaru lists one rear shoe repair kit for the 2.5i, RS, TS, Outback Sport and WRX, and a different kit for the STI. Check which one your car needs before ordering, because the STI kit is not interchangeable with the standard one.

Common Parking Brake Problems and Their Causes

On cars in salt states, the most common long-term failure is corrosion. Rust builds on the drum surface and around the shoe hardware, cable sheaths swell and the inner cable seizes, and the star wheel itself rusts solid so it cannot be turned. A car whose parking brake has not been used for years is the most likely to have a frozen cable or a rusted adjuster.

How to Diagnose It

Start with the simple checks before taking anything apart:

1. Count the clicks. With the engine off, pull the lever up firmly and count the notches. Your service manual gives the correct range; if the lever travels well past it, the system needs adjustment. If it is close but the car still rolls, the problem is the shoes or drums, not slack.
2. Check release. Raise the rear on stands, release the lever fully and spin each wheel by hand. Both should turn freely with only light pad drag from the caliper. A wheel that is noticeably harder to turn points to a stuck cable or overtight shoes on that side.
3. Check apply. Have a helper pull the lever two or three clicks while you try each wheel. Both should lock at about the same point. If one locks and the other spins, that side is out of adjustment or its cable is seized.
4. Look at the cables. Follow each cable from the equalizer under the car to the backing plate. Kinks, split boots, or rust bulging from the sheath mean the cable is due.

Adjusting the Parking Brake the Right Way

The order matters. If you only tighten the cable at the lever, you pull the shoes out by brute force, the lever feels better for a while, and the shoes may start dragging after a few hot drives. Set the shoes first, then the cable.

1. Release the lever fully and loosen the cable adjusting nut at the lever (under the console boot) so the cables are slack. The shoes cannot be set correctly if the cable is holding them partly applied.
2. Raise the rear and remove the wheels. Remove the rubber access plug to reach the star wheel. On some cars it is easier to remove the caliper and rotor and set the adjuster with the drum off.
3. Turn the star wheel with a brake spoon until the rotor will no longer turn by hand, then back it off just until it turns with only a slight drag. Wilwood describes the same method for its own internal drum parking brakes: tighten until the drum is locked, then back off until it rotates.
4. Repeat on the other side so both shoes sit at the same clearance.
5. Now take up the cable slack at the lever nut until the lever reaches the specified number of clicks with firm hand force, as listed in the factory service manual.
6. Release the lever and confirm both rear wheels spin freely. Reinstall the access plugs and wheels, and torque the lug nuts to the factory value.

If the star wheel will not turn, or the shoes are glazed or contaminated, adjusting will not fix it. That is the point to replace parts.

When to Replace Shoes, Hardware, Cables, or Rotors

Replace the parking brake shoes if the lining is thin, cracked, coming away from the shoe, or soaked with grease or brake fluid. Replace the hardware (springs, hold-downs, adjuster) at the same time; old springs lose tension and a rusted adjuster will not stay set. Shoes and springs are covered in our brake shoes and brake hardware kits sections.

Because the parking drum is part of the rear rotor, a badly scored or rusted drum surface means a new rotor. If the rear rotors are near their minimum thickness anyway, replacing them as a pair with fresh rear brake rotors and rear brake pads solves the braking surface and the parking surface in one job. Always do both rear wheels together so the parking brake applies evenly.

If a cable is seized, replace it rather than trying to free it; a cable that has rusted once tends to stick again. With new cables, set the shoes first and then adjust at the lever, the same as above.

New shoes need to seat before they hold at full strength. Follow the service manual or the shoe maker's instructions for bedding them in, and test on a gentle slope before you rely on the parking brake on a steep hill.

How Hard Is the Job?

A basic adjustment is a driveway job for someone who can safely raise and support the rear of the car: wheels off, star wheels set, cable nut adjusted. Replacing parking shoes is harder. The caliper and rotor come off, and the shoe springs and hold-downs need patience and the right spring tool. Cables are the most work because they route under the car and up to the lever. If your car also needs rear pads and rotors, doing the parking shoes at the same time saves taking the same parts off twice.

For this generation, NHTSA's recall database shows no parking brake recall for the 2005 Impreza; its campaigns for that year cover passenger airbag inflators and front lower control arm corrosion. Run your own VIN at nhtsa.gov to confirm nothing is open on your car.

Frequently Asked Questions

Does the 2004-2007 Impreza have rear drum brakes?

US-market cars use rear disc brakes. The only drum is the small parking brake drum built into the hat of each rear rotor, with its own set of shoes.

Why does my Impreza roll with the parking brake fully on?

Usually the shoes are out of adjustment, glazed, or the drum surface is rusted. Adjust the star wheels first; if it still rolls, pull the rotors and inspect the shoes and drums.

Can I just tighten the cable at the lever?

Only after the shoes are set at the wheels. Tightening the cable alone pulls the shoes partly on and can cause drag and heat at the rear wheels.

Are WRX and STI parking brake shoes the same as the 2.5i?

The WRX shares its rear parking shoe kit with the 2.5i, RS, TS and Outback Sport. The STI uses its own, different shoe kit.

Should I replace rear rotors when I do the parking brake shoes?

Replace them if the inner drum surface is scored, out of round, or heavily rusted, or if the rotor is near minimum thickness. Otherwise the rotors can be reused.

Sources

1. CarSpecs: 2006 Subaru Impreza 2.5i specifications - front and rear disc brakes, four-channel ABS
2. Genuine Subaru rear brake shoe repair kit 26298AA020 - parking shoe fitment for 2.5i, RS, TS, Outback Sport and WRX
3. Genuine Subaru rear brake shoe repair kit 26298PA080 - separate STI parking shoe kit
4. Genuine Subaru Impreza WRX parking brake shoe listings - parking shoes act against the drum wall
5. Wilwood: How to adjust the internal drum parking brake - star-wheel tighten-then-back-off method
6. NHTSA recalls: 2005 Subaru Impreza - recall list, no parking brake campaign