AfterMarketNews Auto Care Pro AutoProJobs Auto-Video.com Brake&Frontend BodyShopBusiness Counterman EngineBuilder Fleet Equipment ImportCar Motorcycle & Powersports News Servicio Automotriz Shop Owner Tire Review Tech Shop Tomorrow's Tech Underhood Service

The Problem With Living In The 'Now'

I once had a shop manager who concentrated on the “now.” Every day was a mad dash to complete the jobs at hand. He wanted to know who was working on what, where the parts were and when everything would be done. He was constantly reacting to a customer’s...

Read more...

ASE G1: Drive Belt Inspection, Replacement

The ASE G1 Certification test contains 55 scored questions, plus 10 unscored ­research questions, that cover a range of skills and knowledge related to maintenance and light repairs in engine systems, automatic transmission/transaxle, manual drivetrain...

Read more...

Amateurs and Hacks Provide Job Security For Automotive Service Professionals

Two cars pull up in front of my shop. The drivers didn’t come in, but I heard the commotion from my office window. The boyfriend opens the hood of his girlfriend’s car. They both stare at the engine; she tells the boyfriend that she was supposed...

Read more...

Acura: Clunk Noise While Turning

Model: Acura RSX 2005-’06 Symptom: The front suspension makes a ­clunking noise while turning. Probable Cause: The front springs are moving on the spring seats. Corrective Action: Replace both front springs and do a four­-wheel alignment. Diagnosis:...

Read more...

Inside Import Car Collision Warning, Automatic Braking Systems

Anything that moves under its own power also has to stop, so brakes have been a safety feature on cars since day one. Over the years, technical innovations such as antilock brakes (ABS) have ­improved the ability to stop with minimal skidding on...

Read more...

Intermittent Engine Misfire Analysis

Even for an experienced diagnostic technician, ­attempting to diagnose an intermittent misfire ­condition that occurs only under specific driving conditions can be a frustrating exercise. Let’s begin by getting the basics out of the way. As we know,...

Read more...

Analyzing the Cylinder Pressure Waveform from a Running Engine, Part 3

By Vasyl Postolovskyi and Olle Gladso Contributing Writers and Instructors at Riverland Technical and Community College in Albert Lea, MN   In Part 1 of this Maximizing Tools series, we discussed an alternative approach to diagnosing an engine...

Read more...

Mac Tools Is Wrenching for a Cure

In support of Breast Cancer Awareness month, Mac Tools is featuring a variety of Wrenching For A Cure products available for purchase in the Flyer 11 through Nov. 2. Featured pink products include clothing, accessories, flashlights, pint glasses, and...

Read more...

5 Tool Storage Tips

  As a technician, you likely own thousands of dollars worth of tools and equipment, and require tool storage capacity to hold them all, along with carts and accessories to help move those tools around your work area. Here are a few items...

Read more...

Battery Service and Diagnosis

A good battery with an adequate charge is absolutely essential for reliable cold starting. A weak battery, or one that is rundown, may not deliver enough amps to crank the engine when temperatures plunge and the oil thickens. Cold weather can be hard...

Read more...

Toughest Spark Plug Changes

We have all been there before: scratched arms, busted knuckles and an aching back caused by a difficult spark plug replacement job. If you think they are getting tougher every year, you are right. Every new engine design is putting the plugs deeper...

Read more...

Improving the Head Gaskets, Fasteners Relationship

The relationship between head gaskets and head bolts is an intimate one. The clamping load applied by the head bolts is what allows the head gasket to maintain its seal. For this marriage to last, there has to be constant tension – not too much,...

Read more...

Home Brake Job Performing a Brake Job on a 2002-2009 Chevrolet Trailblazer

Print Print Email Email

The Chevrolet Trailblazer is based on the GMT 360. The brake system on the Trailblazer is not groundbreaking by any means, but there are some intricacies technicians should be aware  of on this common platform.

Fronts
The front brakes utilize dual piston calipers with phenolic pistons. The most important thing to remember when replacing the pads on this vehicle is to replace the hardware.

The most critical hardware item is the pad retention clip inside the caliper’s bridge. This clip applies force to the pads and keeps them snug in the bracket. This piece of hardware loses its spring tension due to heat and vibration. This clip comes in most hardware kits along with abutment clips. Some pad manufacturers package it with the pad set.

Do not use cheap pads. The Trailblazer is a heavy vehicle and uses a very aggressive pad compound. I recently had the honor of installing a cheap set supplied by a customer and after three stops to burnish the pads, the front brakes were smoking and I had a longer than normal pedal.

Most inexpensive pad sets will not package the abutment clips and pad retention clips with the pads. Also, less expensive pads will make you install the wear indicators. Most high-quality pads have the wear indicators installed and the hardware in the box.

Always take time to clean and measure runout in the hub flange and when the rotor is installed. Pulsation problems can occur even if new rotors are installed. Maximum lateral runout is .002” and disc thickness variation is .001”.

When using lubricants, do not coat the entire backing plate. Instead, coat just the insides fingers of the calipers, abutment clips and the surfaces of the pad retention clip that make contact with the pad. Do not lubricate the pistons or the backing plate of the inboard pad. The lubricant could adhere to the rubber boots of the pistons and cause debris to stick to the surface and cause the boot to deteriorate due to chemical interaction or dust sticking and abrading the boot.

Rear
The rear brakes use a single piston caliper with the parking/emergency brake in the hat.
Pad replacement is straight forward. Rotor replacement can be difficult and may require the a slide hammer with a right attachments.

When the rotor is off, inspect the parking brake shoe and the clips that hold it to the backing plate. The components should be cleaned and the shoe should be inspected for any signs of the friction material delaminating or cracking.

Parking Brake Adjustment
The Trailblazer is equipped with a self-adjusting parking brake mechanism designed to take up the slack in the cables. To perform a final adjustment, the shoe can be adjusted at the actuator via an adjusting nut. The clearance between the rear park brake shoe lining and the rotor should be 0.25 mm (0.010 in).

If you have to replace the cables or actuators, you have to disable the self-adjusting mechanism.

1. Place the park brake lever in the full release position.

2. Raise and suitably support the vehicle.

3. Pull the park brake cable equalizer toward the rear of the vehicle and place a locking pliers with protected jaws on the cable to hold the cable in an extended position.

4. Lower the vehicle.

5. Rotate the self-adjust clip into the lock position with a flat-bladed tool.

6. Raise the vehicle.

7. Remove the locking pliers from the park brake cable.

8. Lower the vehicle.

9. Partially raise the park brake lever, stopping prior to the self-adjust clip (1) activating on the mount bracket tab.

10. Insert a flat-bladed tool behind the self-adjust clip and twist the tool 90 degrees to raise the self-adjust clip over the mount bracket tab.

11. Raise the handle until it is fully applied and remove the screwdriver.

To Enable
After component replacement, to reengage the the automatic adjuster  complete the sequence below:

1. Lower the park brake lever.

2. Raise the park brake lever.

3. Lift the park brake lever boot to gain access to the multiplier lever at the front of the park brake lever assembly.

4. Pivot the lever up and down 3 times.

5. Cycle the park brake lever up and down three times for auto adjustment.

6. Lower the park brake lever boot.

ABS
The ABS system is a four-channel system with dynamic rear proportioning. The Achilles heal of this system is the wiring harnesses for the front wheel speed sensors. In Rust Belt states, salt and water can penetrate the harnesses causing wheel speed sensor codes to be set. Always test the harness for resistance and voltage drop from the EBCM to the  wheel before you condemn a hub unit.

Some vehicles have had issues with the grounding of the Electronic Brake Control Module’s (EBCM) grounds. TSB 04-05-25-002E outlines this problem and the recommended repair.

If you have a customer come in with a C0196 code set and Stablitrak light illuminated, the problem could be the programming on the EBCM and how it interfaces with the yaw sensor. GM has issued new software update that can correct this problem.

Bleeding
Bleeding can be performed with a number of methods. If the modulator is replaced, you will need a scan tool to cycle the pump. It is also a good idea to do this if the master cylinder is replaced. Always start at the right rear.

Take your time with any bleeding procedure. The first wheel may require up to a full pint of fluid to get all the air bubbles out of the system.

The following two tabs change content below.

Andrew Markel

Andrew Markel is an ASE Certified Technician and former service writer, and he brings this practical knowledge to the Brake & Front End team as editor.

Latest posts by Andrew Markel (see all)

  • sam

    is there an easy way to get the break pads on the clips

Latest articles from our other sites:

ANCO Returns As Official Wiper Blade Of The National Hockey League

Federal-Mogul Motorparts, a division of Federal-Mogul Holdings Corp., announced that its ANCO Wipers brand is returning as the official wiper blade of the National Hockey League (NHL) for the 2014-'15...More

NHTSA Issues Urgent Warning For Airbag Recalls

On Oct. 20, the National Highway Traffic Safety Administration issued an urgent advisory to the owners of some 7.8 million cars throughout the United States about a massive recall for defective airbags. The...More

Acura: Clunk Noise While Turning

Model: Acura RSX 2005-’06 Symptom: The front suspension makes a ­clunking noise while turning. Probable Cause: The front springs are moving on the spring seats. Corrective Action: Replace both...More

Inside Import Car Collision Warning, Automatic Braking Systems

Anything that moves under its own power also has to stop, so brakes have been a safety feature on cars since day one. Over the years, technical innovations such as antilock brakes (ABS) have ­improved...More

New Snap-on Heavy Duty Catalog Offers Array Of Performance-Enhancing Tools And Equipment

The new Snap-on Heavy Duty Catalog showcases some of the most innovative tools and equipment around, including an assortment of hand tools, power tools, shop and tech equipment, tool storage units, mobile...More

Analyzing the Cylinder Pressure Waveform from a Running Engine, Part 3

By Vasyl Postolovskyi and Olle Gladso Contributing Writers and Instructors at Riverland Technical and Community College in Albert Lea, MN   In Part 1 of this Maximizing Tools series, we discussed...More

Battery Service and Diagnosis

A good battery with an adequate charge is absolutely essential for reliable cold starting. A weak battery, or one that is rundown, may not deliver enough amps to crank the engine when temperatures...More

Chemical Gasketing: Cleaning the Surface

Service technicians can now use chemical gaskets where OEs had originally used formed-in-place or pre-cut gaskets during vehicle assembly. In addition to complying with OE specs, chemical gaskets are...More