2006-2011 Hyundai Azera Brake Fluid Type and Flush Interval

By Core Brake Parts Tech Team — Circleville, OH warehouse

The 2006-2011 Hyundai Azera takes glycol-based brake fluid that meets the DOT 3 or DOT 4 specification, poured only from a sealed container. Hyundai's owner's manual for this generation does not set a fixed mileage for flushing it. Instead it calls for a brake fluid inspection at every scheduled service, and the fluid should be replaced when testing shows it has taken on moisture or it has gone dark, which for most owners works out to every two to three years.

What brake fluid the Azera uses

The 2008 Azera owner's manual (this generation of Azera was sold in the US from the 2006 through 2011 model years) states plainly that the braking system should use only hydraulic brake fluid conforming to DOT 3 or DOT 4 specifications. It adds that the fluid should come from a sealed container, and that neither the fluid can nor the reservoir should sit open longer than necessary, so dirt and moisture cannot get in.

DOT 3 and DOT 4 are federal grades defined in Federal Motor Vehicle Safety Standard 116. Both are glycol-ether fluids. The main practical difference is heat tolerance: the standard sets a higher minimum boiling point for DOT 4 than for DOT 3, both when the fluid is fresh and after it has absorbed water.

DOT 5 has the highest numbers on paper, but the Azera manual does not list it, so it does not belong in this car. Stick with DOT 3 or DOT 4. If you do a full flush, it makes sense to pick one grade and use it throughout; DOT 4 gives you more heat margin for mountain driving or towing a light trailer.

How often to check and flush it

This is where a lot of generic advice gets the Azera wrong. The scheduled maintenance chart in the 2008 owner's manual lists brake fluid as an "I" item, meaning inspect and, after inspection, clean, adjust, repair or replace if necessary. That inspection falls at every service interval in the chart, starting at 7,500 miles or 6 months and repeating every 7,500 miles or 6 months after that. There is no "R" (replace) entry for brake fluid on a fixed mileage.

So the factory position is: look at it every time the car is serviced, and change it when it needs it. In practice, glycol fluid does not stay good forever. ADVICS, a major OE brake supplier, explains that glycol-ether fluid is hygroscopic, meaning it pulls moisture out of the air, and that it is considered saturated once it reaches about 3.7 percent water by volume. ADVICS notes that DOT 3 formulas typically need changing about once a year and DOT 4 formulas last about two years before saturation, while still telling owners to follow their owner's manual first.

A sensible plan for an Azera that is now 15 to 20 years old:

• Check the level and color at every oil change, as the manual's inspection schedule intends.
• Test the fluid for moisture or copper content with a test strip or electronic tester at least once a year.
• Flush it whenever testing fails, the fluid is dark, or the history is unknown. If you just bought a used Azera and have no record of a flush, do it now.
• Flush it any time the hydraulic system is opened for major work, such as a caliper or brake hose replacement.

Why old fluid matters on this car

Water in brake fluid does two kinds of damage. First, it lowers the boiling point. Federal Standard 116 sets separate "wet" boiling points precisely because fluid in service absorbs water, and the wet minimums in the table above are far below the dry ones. When the fluid near a hot caliper boils, it forms vapor bubbles that compress, and ADVICS describes the result as vapor lock, a condition where the brakes stop working properly. A long downhill grade with a loaded car is the classic trigger.

Second, the manual itself warns that dirt and moisture can damage the brake system. The Azera has four-wheel disc brakes plus an anti-lock brake system, and the manual also covers Electronic Stability Control. Those systems rely on a master cylinder, an ABS hydraulic unit and caliper pistons with tight internal clearances. Moisture-laden fluid promotes internal corrosion in those parts, and replacing an ABS unit or a set of calipers costs far more than a fluid flush.

Symptoms of fluid that needs attention

• Spongy or soft pedal, especially after heavy braking or a long downgrade. ADVICS lists spongy pedal feel as a warning sign.
• Dark, cloudy or discolored fluid in the reservoir. Fresh DOT 3 and DOT 4 are clear to light amber.
• Low fluid level. The level should sit between the MIN and MAX marks on the side of the reservoir. A slowly dropping level is normal as the pads wear, but a sudden drop points to a leak.
• Red brake warning light. The Azera shares one warning lamp for the parking brake and low brake fluid level. If it stays on with the parking brake fully released, check the fluid level right away.
• ABS warning light along with pedal changes. This can have many causes, but contaminated fluid and a corroded hydraulic unit are on the list.

How to add fluid and what a flush involves

Topping off is simple. The manual's steps: wipe the dirt off the reservoir cap first, unscrew the cap, slowly pour in the recommended fluid, and do not overfill past MAX. Handle the fluid carefully; the manual warns it can damage your eyes, and glycol fluid will also lift paint, so cover the fender and wipe any drips immediately.

A full flush replaces all of the old fluid, not just what is in the reservoir. The usual approach is to pull most of the old fluid out of the reservoir, refill with fresh fluid, and then bleed each caliper in turn until clean fluid comes out, never letting the reservoir run dry so air does not enter the lines. Follow the bleed sequence in the factory service manual. If air gets into the ABS hydraulic unit, the service manual procedure may call for a scan tool to cycle the unit, which is one reason many owners hand this job to a shop.

For a DIYer with a helper or a one-person bleeder, a flush is a one to two hour job. The fluid itself is inexpensive; the time goes into doing it cleanly.

What to do at the same time

The Azera's schedule pairs the fluid check with inspection of the brake hoses and lines, the front pads, calipers and rotors, and the rear disc brakes and parking brake. Doing them together makes sense:

• Pads and rotors. With the wheels off for bleeding, measure pad thickness and check the rotors for scoring and lip wear. We carry a front rotor and ceramic pad kit for the 2006-2011 Azera, and you can browse more ceramic brake pads and brake rotors.
• Calipers. A sticking piston or a torn dust boot is common on older cars run on neglected fluid. If a caliper is seized, replace it before bleeding; see our brake calipers.
• Hoses. The manual says to check hoses and lines for chafing, cracks, deterioration and leakage. Rubber hoses on a car this age are worth a close look; replacements are in our brake hoses section.
• Parking brake. The Azera uses a foot-operated parking brake pedal. The manual says to check it periodically for proper stroke and have it adjusted if it feels loose, because a poorly adjusted parking brake can let the car roll on a steep hill.

Frequently Asked Questions

Can I use DOT 4 in my 2006-2011 Azera if it has DOT 3 in it now?

Yes. The owner's manual approves either DOT 3 or DOT 4. DOT 4 has higher minimum boiling points under the federal standard. For the cleanest result, switch grades during a full flush rather than just topping off.

Can I use DOT 5 silicone fluid?

No. The Azera manual specifies only DOT 3 or DOT 4 fluid. DOT 5 is not listed and should not go in this car.

Does Hyundai say to replace brake fluid at a certain mileage on the Azera?

Not in the 2008 owner's manual. It lists brake fluid as an inspect item at every 7,500 mile or 6 month service, with replacement when the inspection calls for it. Moisture testing is the best way to decide.

Why does my brake fluid level keep going down?

As the pads wear, the caliper pistons move out and the fluid level in the reservoir drops a little. That is normal. A level that falls noticeably between services, or wet spots near a wheel or on the inside of a tire, means a leak that needs to be found before driving further.

Should I flush the brake fluid when I replace pads and rotors?

It is a good time to do it, especially if the fluid is dark or its history is unknown. The wheels are already off, and fresh fluid protects the calipers whose pistons you just pushed back.

Can I tell if fluid is bad just by looking at it?

Dark fluid is a clear sign it is due, but clear-looking fluid can still hold enough water to lower its boiling point. A moisture or copper test strip, or a boiling point tester, gives a real answer.

Sources

1. Hyundai 2008 Azera Owner's Manual - Recommended Brake Fluid - DOT 3 or DOT 4 only, sealed container, MIN/MAX level, adding procedure and handling warnings
2. Hyundai 2008 Azera Owner's Manual - Scheduled Maintenance - brake fluid, hoses, pads, rear disc brakes and parking brake listed as inspect items every 7,500 miles or 6 months
3. Hyundai 2008 Azera Owner's Manual - Explanation of Scheduled Maintenance Items - what to check on brake fluid, hoses and lines, rear discs and parking brake
4. Hyundai 2008 Azera Owner's Manual - Checking Parking Brake Pedal - foot-pedal parking brake stroke check and adjustment warning
5. 49 CFR 571.116 (FMVSS 116) Motor Vehicle Brake Fluids - dry and wet boiling point minimums for DOT 3, DOT 4 and DOT 5; clean-and-dry container warnings
6. ADVICS - Brake Fluid Boiling Points - hygroscopic glycol-ether fluid, 3.7 percent water saturation, vapor lock and symptoms, typical DOT 3 and DOT 4 life