2008-2015 Scion xB Brake Job Guide: Symptoms, Costs and the Right Parts

By Core Brake Parts Tech Team — Circleville, OH warehouse

The 2008-2015 Scion xB stops on four-wheel disc brakes: ventilated rotors up front, solid rotors in back, with ABS, electronic brake-force distribution and Brake Assist standard. A typical brake job means front pads and rotors first, rear pads and rotors later, plus a fluid check with DOT 3. If you hear a steady squeal or scrape when braking, the pad wear indicators are telling you the job is due now.

How the Second-Generation xB Brake System Works

When Scion redesigned the xB for 2008 it grew into a larger, heavier box on a 2.4-liter 2AZ-FE four-cylinder, and the brakes grew with it. Scion's launch information lists 10.83-inch ventilated front discs and 10.98-inch rear discs, more than two inches larger than the first-generation car, along with four-wheel ABS, Electronic Brake Distribution (EBD), Brake Assist and Vehicle Stability Control with traction control. Unlike many small cars of the era, there are no rear drums to deal with.

The hydraulics are conventional Toyota. The owner's manual describes a tandem master cylinder feeding two separate sub-systems, so if one side of the system fails the other still stops the car, just with a harder pedal and a longer stopping distance. Power assist comes from a vacuum brake booster driven by engine vacuum. The parking brake is a hand lever between the seats, and the manual's specification is 6 to 9 clicks when the lever is pulled with 196 N (44 lbf) of force.

Symptoms That Your xB Needs a Brake Job

• Squealing or scraping when you brake. The xB's disc brakes carry pad wear limit indicators that make a warning noise when the pads reach replacement thickness. Toyota's manual says to have the pads replaced as soon as possible when you hear it, because running past that point damages the rotors.
• Grinding. Metal-on-metal means the friction material is gone and the backing plate is cutting the rotor. At that stage rotors are no longer optional.
• Pulsation in the pedal or shake in the steering wheel. Usually uneven rotor thickness or pad material deposits on the front rotors, which do most of the work.
• Brake fluid level creeping down. The manual notes the level drops slightly as pads wear, so a low reservoir is often a sign of thin pads. If it needs frequent topping off, look for a leak instead.
• Brake warning light. On the xB this light can mean the parking brake is on or the fluid level is low. If it stays on with the parking brake released, stop and have the system checked.
• Low or long pedal. The manual lists a minimum pedal clearance of 87 mm (3.4 in.) with 294 N applied and the engine running. A pedal that sinks closer to the floor points to air, a leak or a failing master cylinder.

Front vs Rear: What Wears and in What Order

Weight shifts forward under braking, so the front ventilated rotors and pads handle most of the load and wear out first on nearly every xB. Plan on the front axle being the first brake job, with the rear pads lasting noticeably longer. Because EBD balances rear brake force against load, a loaded xB (and many were bought to haul people and cargo) will work the rear brakes a little harder than a lightly loaded one.

The rear discs are solid rather than vented, and they tend to fail differently: surface rust and a lip at the edge from sitting, sticking slide pins, and a parking brake that needs more clicks than it should. When you do the rears, check that the parking brake still sets within the 6 to 9 click range afterward.

What to Replace Together

Always replace pads as an axle set, both sides at once. Beyond that, here is what a proper xB brake job covers:

• Pads. A quality ceramic brake pad suits most xB owners: low dust, quiet, and well matched to a daily driver. Browse all brake pads if you want semi-metallic for heavier loads.
• Rotors. If the rotors are scored, grooved, lipped or cause pulsation, replace them with the pads. New brake rotors are often the better choice over machining because resurfacing removes material the rotor needs to shed heat.
• Hardware. Abutment clips and anti-rattle springs lose tension over time. A brake hardware kit is inexpensive and prevents rattles and uneven pad wear.
• Calipers and hoses as needed. A caliper that sticks, leaks or wears one pad much faster than the other should be replaced, and cracked or swollen rubber lines should be swapped for new brake hoses.
• Fluid. Use only SAE J1703 or FMVSS No. 116 DOT 3 fluid from a freshly opened bottle, as Toyota specifies. Opened fluid absorbs moisture, and moisture lowers the boiling point.

Not sure which combination fits your car? A pads-and-rotors kit for one axle is the most common xB purchase, and you can shop the full range in our brake parts catalog.

The TRD Brake Kit Recall (J0U)

Some xB owners added the optional Toyota Racing Development big brake kit. NHTSA campaign 18E091000 (Toyota recall J0U) covers TRD brake kits with part numbers PTR09-21111 and PTR09-52080 sold as accessories for 2008-2015 Scion xB and 2011-2016 Scion tC. The brake hoses in those kits can fatigue and fail over time, which reduces braking performance. The remedy is replacement of the TRD kit with standard equipment brakes at no charge. If your xB has an aftermarket-looking big brake setup and you bought it used, check the VIN for open recalls before ordering parts, because the standard-equipment parts discussed here assume a factory brake system.

How Hard Is the Job, and What Drives the Cost?

A front pad and rotor job on the xB is a straightforward bolt-on job for anyone with a jack, stands, a torque wrench and a C-clamp or piston tool. The front calipers slide off their brackets, the bracket comes off to free the rotor, and everything goes back in reverse. Torque the caliper and bracket bolts, and the lug nuts, to the values in the factory service manual; do not guess. The rear axle is similar but adds the parking brake, so read the procedure for your year before you start and confirm the lever travel afterward.

What you pay depends on a few factors rather than a single number:

• Pads only vs pads and rotors. Rotors add parts cost but save a second teardown later.
• One axle vs both. Fronts alone is the common first job; doing both axles at once costs more today but consolidates labor.
• Shop labor vs DIY. Labor is usually the biggest variable. Doing it yourself turns the job into parts cost only.
• Extra parts found during the job. A seized caliper, a torn hose or a fluid flush adds to the bill, which is why you should inspect before ordering.

After any brake job, pump the pedal until it is firm before moving the car, then bed the new pads in with a series of moderate stops so the friction material transfers evenly to the rotor.

Frequently Asked Questions

Does the 2008-2015 Scion xB have rear drum brakes?

No. The second-generation xB uses disc brakes at all four wheels: 10.83-inch ventilated discs in front and 10.98-inch discs in the rear.

What brake fluid does a Scion xB use?

Toyota specifies SAE J1703 or FMVSS No. 116 DOT 3 brake fluid. Use a freshly opened container and fill to the MAX line on the reservoir.

How thin can Scion xB brake pads get before replacement?

The owner's manual lists a pad wear limit of 1.0 mm (0.04 in.). In practice, replace them well before that, when the wear indicators start to squeal.

Should I replace the rotors every time I replace the pads on my xB?

Not always. If the rotors are smooth, flat and free of a heavy lip or pulsation, new pads alone are fine. If you feel pulsation, see deep grooves, or the pads went metal-to-metal, replace the rotors too.

Why does my xB brake warning light stay on?

The light comes on with the parking brake applied or when the brake fluid level is low. If it stays on after releasing the parking brake, check the fluid level, and stop driving and have the system inspected if the level is low.

Is the TRD brake kit on my xB under recall?

If it is a TRD kit with part number PTR09-21111 or PTR09-52080, it falls under NHTSA campaign 18E091000 (Toyota J0U). A Toyota dealer can confirm by VIN and replace it with standard brakes at no charge.

Sources

1. Scion xB Owner's Manual (Toyota) - DOT 3 fluid spec, pad wear limit, pedal clearance and free play, parking brake clicks, wear indicators, tandem master cylinder and vacuum booster
2. 2008 Scion xB specifications, Conceptcarz - 10.83-inch ventilated front and 10.98-inch rear discs, ABS, EBD, Brake Assist, VSC and TRAC
3. NHTSA Safety Recall J0U notice - TRD brake kit recall for 2008-2015 xB
4. NHTSA campaign 18E091000 record - TRD kit part numbers, brake hose fatigue defect and free replacement remedy
5. Consumer Guide, 2008-14 Scion xB - all-disc antilock brakes and stability control standard, 2.4-liter engine