2006-2009 Ford Fusion Brake Fluid Type and Flush Interval

By Core Brake Parts Tech Team — Circleville, OH warehouse

The first-generation Ford Fusion uses DOT 3 brake fluid. Ford's owner guide lists Motorcraft High Performance DOT 3 Motor Vehicle Brake Fluid, part number PM-1-C, meeting Ford specification WSS-M6C62-A, filled to between the MIN and MAX marks on the reservoir. Ford's normal maintenance schedule for cars does not set a fixed brake fluid change interval, so the practical rule is to test the fluid at every brake inspection and replace it whenever it fails the test, looks contaminated, or the hydraulic system is opened for repair.

What Ford Specifies for the 2006-2009 Fusion

The Maintenance Product Specifications and Capacities table in the Fusion owner guide lists one brake fluid for the car. It is the same fluid whether you have the 2.3L four-cylinder or the 3.0L Duratec V6, and whether the car has an automatic or a manual transaxle.

If you buy a fluid other than the Motorcraft product, read the bottle. It should say DOT 3 and, ideally, state that it meets Ford WSS-M6C62-A. The part number and spec are also useful when you ask a parts counter for the right fluid, because "DOT 3" alone covers a wide range of quality.

What the DOT rating actually means

DOT ratings come from Federal Motor Vehicle Safety Standard 116. The standard sets minimum boiling points for new, dry fluid and for fluid that has been humidified in a test, which it calls the wet boiling point. The wet number exists because glycol-based fluid absorbs water from the air over time, and water lowers the boiling point.

Two practical points follow. First, a quality DOT 4 fluid is also glycol-based and exceeds DOT 3 minimums, which is why many shops use it in DOT 3 systems; if you go that way, pick one that meets the Ford spec and do a full flush rather than topping off. Second, never put silicone DOT 5 in a Fusion. The federal standard makes silicone fluid purple precisely so nobody mixes it into a glycol system by mistake.

How the Fusion Brake Hydraulics Work

The brake fluid reservoir sits on top of the master cylinder. On the 2.3L four-cylinder, Ford's engine-compartment diagram labels it the brake/clutch fluid reservoir; on the 3.0L V6 it is labeled the brake fluid reservoir. Ford's vehicle symbol glossary marks brake fluid as non-petroleum based, a reminder that oil-based products must never go in.

On manual-transaxle cars, the brake and clutch systems draw from the same reservoir. That matters when you service the fluid: flushing only the four brake bleeders leaves old fluid sitting in the clutch master and slave cylinder. If your Fusion has a manual transaxle, bleed the clutch circuit too.

The system also runs through the anti-lock brake hydraulic unit on cars that have ABS. A normal flush that never lets the master cylinder run dry pushes fresh fluid through it. If air gets into the ABS unit, follow the bleed procedure in the factory service manual, which may call for a scan tool.

Symptoms of Low or Worn-Out Brake Fluid

Ford builds two warnings into the Fusion for fluid level. If the red BRAKE light stays on after you release the parking brake, the owner guide says that indicates low brake fluid or a brake system malfunction, and the system should be inspected right away. Cars with the message center can also display LOW BRAKE FLUID or CHECK BRAKE SYSTEM.

Old fluid usually does not trigger a warning. Watch for these instead:

• A soft or sinking pedal, especially after repeated hard stops or a long downhill run. Moisture-laden fluid can boil in the calipers and create vapor, which compresses.
• Dark, cloudy fluid in the reservoir, or fluid with debris in it. Ford notes that some discoloration can be normal, so use a test rather than color alone to decide.
• Corrosion-related problems such as sticking caliper pistons or a leaking wheel cylinder, which water in the fluid encourages over the years.

The most reliable check is a brake fluid test strip or an electronic moisture tester dipped in the reservoir. If it reads out of range, flush the system.

Why the Reservoir Level Drops (and When Not to Top It Off)

The owner guide explains that the fluid level drops slowly as the brakes wear and rises again when brake parts are replaced. As pads get thinner, the caliper pistons sit farther out, and fluid moves from the reservoir to fill the space behind them. A level near MIN on a car with worn pads is often a sign the pads are due, not that the system is leaking.

Ford is clear that anywhere between MIN and MAX is normal and needs no fluid added. Topping off a low reservoir on worn pads just means it will overflow when new pads push the pistons back. If the level is below MIN, find out why: check pad thickness first, then look for wetness at each wheel, along the lines and hoses, and at the back of the master cylinder.

If the pads are the reason, that is the repair. We carry rear pad sets that fit the 2006-2009 Fusion 2.3L, including the EBC Yellowstuff DP41766R rear brake pad set and the EBC Redstuff DP31766C rear brake pad set. First-generation Fusions came with different rear brake setups, so look behind a rear wheel to confirm your car has rear discs before ordering rear pads or rotors.

How Often to Flush Fusion Brake Fluid

Ford's scheduled maintenance guide for this era splits service into a Normal Schedule for cars and minivans and a Special Operating Conditions schedule. The normal car schedule calls for inspecting the brake pads, rotors, drums, lines, hoses and parking brake at the 15,000-mile service intervals, but it does not list a time or mileage interval for replacing brake fluid on the Fusion. The only brake fluid change exception in that guide is for Class A motorhomes.

For cars in extensive idling or low-speed use, such as delivery, taxi or patrol work, Ford calls for a brake system inspection every 5,000 miles. The same guide says fluids should be changed at the specified interval or in conjunction with a repair, and that flushing should use the same fluid the system requires.

Because there is no fixed number, base the decision on the fluid's condition:

• Test the fluid at every brake inspection and every pad or rotor job.
• Flush whenever the test fails. On a Fusion that is now well over a decade old, if you have no record of a flush, assume it is due.
• Flush after any repair that opens the hydraulic system, such as a caliper, hose, line or master cylinder replacement.
• Flush sooner if you tow, drive in hills, or live somewhere humid.

Doing the Flush and What to Replace at the Same Time

A brake fluid flush on a Fusion is a moderate DIY job with a helper or a one-person bleeder kit. The basic process is to remove the old fluid from the reservoir, refill with fresh DOT 3 from a sealed container, then bleed each wheel until clean fluid comes out, never letting the reservoir run dry. Work from the wheel farthest from the master cylinder toward the closest unless the factory service manual gives a different sequence, and bleed the clutch circuit on manual cars.

Handle the fluid with care. Ford's safety data sheet for its DOT 3 fluid lists it as a glycol ether-based product that causes serious eye irritation, so wear eye protection. Brake fluid also damages paint; wipe spills immediately. Keep the bottle capped because open fluid absorbs moisture, and never reuse fluid that has been bled out.

While the wheels are off, inspect the parts that the fluid touches and the parts that wear with it:

• Pads and rotors. Measure pad thickness and check rotors for scoring. For rear discs on the 2.3L, the EBC USR slotted rear rotors USR1197 fit this car. Browse more brake pads and brake rotors.
• Rubber brake hoses. Look for cracks, bulges or wet spots. Hoses on a car this age are often original. See our brake hoses.
• Calipers. A stuck piston or torn boot often shows up during a flush. Replacement units are in brake calipers.
• Bleeder screws. Seized bleeders are common on older cars; soak them in penetrant before you start and use a six-point wrench.

If the pedal stays soft after a thorough bleed, or the reservoir keeps dropping with no visible leak, suspect an internal master cylinder leak and have the system checked. Our brake parts section covers the rest of the hydraulic system.

Frequently Asked Questions

What brake fluid does a 2006-2009 Ford Fusion take?

DOT 3. Ford lists Motorcraft High Performance DOT 3 Motor Vehicle Brake Fluid, part number PM-1-C, meeting Ford specification WSS-M6C62-A, for both the 2.3L and 3.0L engines.

Can I use DOT 4 in my Fusion?

DOT 4 is glycol-based and exceeds DOT 3 boiling point minimums, so it is compatible with a DOT 3 system. Choose one that states it meets the Ford spec, and do a complete flush instead of mixing the two. Never use silicone DOT 5.

How much brake fluid does the Fusion hold?

Ford does not publish a volume in the owner guide; it lists the capacity as between MIN and MAX on the reservoir. For a full flush, buy enough to push clean fluid through all four wheels and the clutch circuit if equipped, plus some extra.

Does Ford require a brake fluid change at a set mileage on this car?

Not on the normal car schedule for this era. Ford calls for brake system inspections and says fluids should be changed with related repairs. Test the fluid at each inspection and flush it when the test fails.

Why is my Fusion's brake fluid low but there is no leak?

Worn pads are the most common reason. As the pads wear, fluid moves out of the reservoir into the calipers. Check pad thickness before adding fluid, since new pads will push the level back up.

Is the clutch fluid separate on a manual Fusion?

No. On manual-transaxle Fusions the brake and clutch systems share one reservoir and the same DOT 3 fluid, so bleed the clutch when you flush the brakes.

Sources

1. Ford: 2008 Fusion Owner Guide - brake fluid spec (PM-1-C, WSS-M6C62-A), capacity between MIN and MAX, shared brake/clutch reservoir, level drop with pad wear, warning light and message center behavior
2. Ford: 2007 Model Year Scheduled Maintenance Guide - normal car schedule brake inspections, no fixed brake fluid interval for cars, 5,000-mile brake inspection for severe use, fluid change and flushing guidance
3. 49 CFR 571.116 (FMVSS 116), Legal Information Institute - DOT 3, DOT 4 and DOT 5 dry and wet boiling point minimums and required colors
4. Motorcraft High Performance DOT 3 Brake Fluid Safety Data Sheet - glycol ether composition and eye irritation hazard