Underhood: Audi Tech Tip: Passenger Compartment Not Warming Up?
The seventh-generation Honda Accord (2003-’08) and Acura TL are some of the top-selling vehicles in the U.S.
They have a very simple brake system to service, but it can be prone to brake-noise issues if it’s not properly serviced.
The system uses single-piston floating calipers in the front.
In the rear, some models use single-piston floating caliper disc brakes with a ratcheting-style parking brake. Low-end versions of the Accord use drums in the rear.
Late-model Acura TLs use a disc brake system with a drum-in-hat style parking brake.
Almost every seventh-generation Accord comes with ABS. All have standard Electronic Brake Distribution (EBD), so don’t look for a proportioning valve.
Most 2006-’08 models have Brake Assist Systems that help recognize emergency braking situations and momentarily apply extra brake force in a “panic stop” or until the driver releases the brakes.
The system uses inputs from steering position, yaw and pitch to determine if brake assist will be used.
If the steering position sensor is not calibrated, it has been reported that the misinformation from the sensor causes the ABS and stability control system to activate during some maneuvers and during cornering when it’s not needed.
Customers may report loss of speed and changes in the brake pedal level during braking and turning. The condition commonly happens on freeway exits. If a customer reports these symptoms, it may save you some time if you look at the output for the steering position sensor.
The seventh-generation Accord brake system comes in two versions and with two different rear brake systems.
Systems are made by either Akebono or Nissin.
When ordering pads, make sure you have a VIN and production date. Also, find out if the vehicle is equipped with ABS and/or TCS. Some brake part electronic catalogs might ask for the trim level.
The smaller brake system came with 15-inch wheels and the larger system came with 16-inch or larger wheels.
But, some special editions and later models violate these rules.
The DX model is the low-end of the range and is equipped with the smaller front brakes and rear drums. The LX version is the mid-range model and can have either brake system, depending on whether it’s equipped with 4-cylinder or V6. Also, the level of ABS and stability control will determine if it’s equipped with rear disc brakes.
The next trim level is the EX.
These models typically have the larger front and rear disc brakes.
Don’t skimp on the brake pads. All the Accords of this generation are designed to work with ceramic friction formulations. It’s critical that a similar friction material goes back on the vehicle. If an aggressive semi-metallic friction material is used, more heat could be transferred to the caliper piston, making it possible to boil the brake fluid.
The problem becomes even worse if you use a cheap brake pad set that does not include a set of shims.
Honda engineers use this design to stop the vibrations so Honda can use a lighter caliper and knuckle to increase gas mileage and improve ride quality.
If you think you can out-engineer a bunch of Honda engineers with a cheap shim and tube of brake lube, you may have a comeback in the near future.
• The best piece of advice provided by one Honda technician is to remove the bolt that holds the front brake hose bracket on the knuckle before you start a brake job. It makes it easy to hang the caliper out of the way and to service the pads and caliper bracket.
• Inspect the bushings and ball joint on the upper control arm. If these components are worn, they will produce a clunking noise during initial braking.
• Make sure the notch in the rear caliper piston is lined up with the tab on the in-board rear brake pad. Failure to do this could make it difficult to reassemble the rear brake assembly and cost you time and money.
Bleeding the System
1. Make sure the brake fluid level in the reservoir is at the MAX (upper) level line.
2. Attach a length of clear drain tube to the bleed screw.
3. Have someone slowly pump the brake pedal several times, and then apply steady pressure.
4. Starting at the left front, loosen the brake bleed screw to allow air to escape from the system.
Then securely tighten the bleed screw. Move to the right front next, followed by the right rear and the left rear.
5. Repeat the procedure for each wheel in the sequence until air bubbles no longer appear in the fluid.
6. Test-drive the vehicle.
7. If the brake pedal is now spongy, there may be air trapped in the modulator and then induced into the normal brake system during modulation. Exercise the ABS and bleed the brake system again, starting with the front wheels.
The rotors on the seventh-generation Accord have a good reputation with technicians. Most technicians report front rotors can be turned at least once before they are below service limits.
Honda issued a TSB in 2007 advising technicians that 2003-’07 4-cylinder Accords could develop a brake judder that could be felt by drivers in the steering wheel due to uneven rotor wear (thickness variation).
Honda’s corrective action was to replace the brake pads and refinish the rotors. Also, Honda tightened up the specs for runout and thickness variation during this time.
Tech Tip: Remember Your Runout — For the front or rear rotors, set up the dial gauge against the rotor and measure the runout at 10 mm from the outer edge of the disc. The overall brake disc runout (front or rear) cannot exceed 0.10 mm. If the front rotors are beyond the service limit, refinish the brake disc.
Front Brake Disc Specs:
15-inch brake type: 22.9-23.1 mm
Max. Refinishing Limit: 21.0 mm
16-inch brake type: 27.9-28.1 mm
Max. Refinishing Limit: 26.0 mm
Rear Brake Disc Specs:
8.9-9.1 mm (0.35 – 0.36 in.)
Max. Refinishing Limit:
1. Remove the brake hose-mounting bolt.
2. Remove the lower flange bolt while holding the flats behind the flange with a wrench. Do not spin the caliper pin in the bore. Damage can occur to the bore and pin boot.
3. You can rotate the caliper upward and secure it if you’re replacing just the pads. If not, remove the upper flange bolts.
4. Remove the brake pads and pad shims. New pads should have a thickness of 10.5-11.5 mm and the pads should be replaced once the friction material is worn below 1.6 mm.
5. Check the hose and pin boots for damage and deterioration. Remove the pins and coat with a silicone-based caliper grease.
6. Remove the pad retainers/abutment clips and check the caliper pins for free movement.
7. Clean the caliper and slides thoroughly. Remove any rust, and check for grooves and cracks.
8. Clean and install the brake pad retainers.
9. Apply a light coat of molybdenum-based lubricant to the pad retainers, pad sides of the shims and the back of the brake pads. Wipe excess paste off the pad shim and brake pads.
10. Install the new brake pads and shims. Install the brake pads with the wear indicator on the inside. The wear indicator should be on the top of the pad.
11. Gently push in the piston so the caliper will fit over the new rotor and/or pads.
12. Install the flange bolt and tighten it to 26 ft.-lbs. for the smaller system and 37 ft.-lbs. for the larger system.
13. Install the hose-mounting bolt.
14. Test-drive the vehicle.
1. Remove the lower flange bolt while holding the flats behind the flange with a wrench. Do not spin the caliper pin in the bore. Damage can occur to the bore and pin boot.
2. Remove and inspect the pads. New pads should have a thickness of 8.9-9.1 mm and the pads should be replaced when the friction material is worn below 1.6 mm.
3. Remove the pad shims.
4. Remove the pad retainers.
5. Clean the caliper thoroughly. Remove any rust and check for grooves and cracks.
6. Check the brake disc for damage and cracks.
7. Install the pad retainers.
8. Apply a thin coat of molybdenum-based lubricant to both sides of the shim and to the back of the brake pads. Wipe excess lubricant off the pad shims and brake pads.
9. Install the brake pads and pad shims. Install the brake pad with the wear indicator on the inside bottom. If you’re reusing the brake pads, always reinstall the brake pads in their original positions to prevent a momentary loss of braking efficiency.
10. Rotate the caliper piston clockwise into the cylinder, then align the cutout in the piston with the tab on the inner pad by turning the piston back. Lubricate the boot with rubber grease to avoid twisting the piston boot. If the piston boot is twisted, back it out so it’s positioned properly.
11. Install the caliper. Install the flange bolts, and tighten it to the specified torque 17 ft.-lbs.
12. Press the brake pedal several times to make sure the brakes work.
1. Pull the parking brake lever with 44 lbs. of force to fully apply the parking brake (use a fish scale). The parking brake lever should be locked within three to five clicks.
2. Adjust the parking brake. For vehicles with drum brakes, loosen the parking brake adjusting nut, start the engine and press the brake pedal several times to set the self-adjusting brake before adjusting the parking brake.
3. Remove the center console.
4. Pull the parking brake lever up one click.
5. Tighten the adjusting nut until the parking brake drags slightly when the rear wheels are turned.
6. Release the parking brake lever fully, and check that the parking brakes do not drag when the rear wheels are turned. Re-adjust if necessary.
7. Pull the parking brake all the way up, and make sure the parking brakes are fully applied.
8. Reinstall the center console.