2012-2018 Ford Focus Brake Fluid Type and Flush Interval

By Core Brake Parts Tech Team — Circleville, OH warehouse

A 2013 through 2018 Ford Focus calls for DOT 4 Low Viscosity (LV) brake fluid meeting Ford specification WSS-M6C65-A2 and ISO 4925 Class 6, sold by Ford as Motorcraft PM-20. The 2012 model year owner's guide instead lists DOT 3 fluid (Motorcraft PM-1-C, WSS-M6C62-A or WSS-M6C65-A1). The Focus normal maintenance schedule has no fixed brake fluid change interval, but Ford's own product sheet for PM-20 recommends servicing every three years, which is the sensible plan for a daily driver.

Which Brake Fluid Your Focus Takes, by Model Year

The third-generation Focus changed fluid spec after its first year, so the model year on your door jamb matters. Here is what each Ford owner's guide lists in its Capacities and Specifications chapter:

The 2013 guide is the odd one: its parts table still prints the older PM-1-C number next to the new WSS-M6C65-A2 spec, while the footnote says to use only DOT 4 LV fluid meeting WSS-M6C65-A2 and ISO 4925 Class 6. Follow the specification, not the part number. A DOT 4 LV Class 6 fluid satisfies the 2013 footnote and is the fluid Ford specifies for every later year.

For a 2012, Ford's PM-20 sheet states the fluid is intended for Ford vehicles specifying WSS-M6C65-A2 or WSS-M6C65-A1, and the 2012 guide accepts WSS-M6C65-A1. So a 2012 can take either the listed DOT 3 or the DOT 4 LV fluid. Check the cap on your reservoir and the owner's guide for your exact car before you buy.

One more detail every Focus owner with a manual gearbox should know: the owner's guide lists the entry as "Brake fluid (and clutch fluid, if equipped)". On the manual-transmission Focus, the hydraulic clutch uses the same fluid as the brakes, so the same spec covers both. The PowerShift dual-clutch automatic does not use brake fluid for its clutches; it has its own dual clutch transmission fluid.

What DOT 4 LV Actually Means

DOT 3 and DOT 4 are both glycol-based fluids defined by Federal Motor Vehicle Safety Standard 116. The standard sets minimum boiling points and a maximum cold viscosity:

The "LV" is the part that matters on a Focus. A plain DOT 4 is allowed to be as thick as 1,800 mm2/s at -40 C. Ford's PM-20 is rated at 750 mm2/s maximum, less than half that. Ford's product sheet says this fluid is recommended for ABS systems with stability control. The ABS and stability-control unit on the Focus moves fluid through small valves very quickly to brake individual wheels, and thin fluid lets it do that on a cold morning. ISO 4925 Class 6 is the international grade for this kind of low-viscosity fluid, which is why Ford lists it alongside its own spec.

Ford's own wording is blunt: the 2014 guide says use of any fluid other than the recommended fluid may cause brake system damage, and the 2016 guide says it may cause degraded brake performance. Do not put DOT 5 silicone fluid in a Focus. It is a different chemistry and does not meet the Ford specification.

How Often to Flush Brake Fluid on a 2012-2018 Focus

Look through the scheduled maintenance section of a 2012 or 2014 Focus owner's guide and you will find inspections of brake pads, rotors, drums, hoses and the parking brake, plus a brake fluid level check in the multi-point inspection, but no line that says "replace brake fluid" at a set mileage for a normal passenger car. That does not mean the fluid lasts forever.

Glycol brake fluid absorbs water from the air over time. That is the reason FMVSS 116 publishes a separate "wet" boiling point, and the reason every legal container must be labeled to be kept tightly closed to prevent absorption of moisture. As water content rises, the boiling point drifts from the dry number toward the wet number. For PM-20 that is a drop from 260 C toward 170 C. Water in the fluid also corrodes steel lines, caliper bores and the valves inside the ABS unit from the inside.

Ford's product sheet for Motorcraft PM-20 recommends servicing every three years. That is the interval we recommend for any 2012-2018 Focus. Flush sooner if any of these apply:

• The fluid in the reservoir has turned dark brown or has visible debris in it.
• You are replacing a caliper, hose, brake line or master cylinder, which opens the system anyway.
• The pedal feels soft or sinks after repeated hard stops or a long downhill grade.
• The car lives in a humid climate or has years of missing service history.
• On a manual car, the clutch pedal feels spongy or does not return, since the clutch uses this fluid.

The owner's guide itself notes that some fluid discoloration is normal and does not by itself mean the fluid must be changed. Color is a hint, not a test. An electronic brake fluid tester or test strips give a better read on moisture content.

Symptoms of Old or Low Brake Fluid

The Focus warns you about low fluid directly. The instrument cluster shows a "Brake fluid level low, Service now" message, and the red brake system warning light comes on if the parking brake is released and the fluid is low or the system has a fault. Ford's guide warns that driving with this light on is dangerous because the car will take longer to stop.

Brake fluid does not get used up. If the level falls, it is almost always for one of two reasons:

• Worn pads. As pads wear, the caliper pistons move out and more fluid sits in the calipers, so the reservoir level drops slowly. If the level is near MIN and the pads are thin, the pads are the fix, not more fluid.
• A leak. Check the inside of each wheel, the hoses at each corner, the lines along the body, and the back of the master cylinder. A wet caliper or a seeping hose needs to be replaced before you flush.

Old fluid that has absorbed water shows up as a pedal that goes soft when the brakes are hot, a pedal that feels fine cold but fades on a long descent, and in later stages sticking caliper pistons from internal corrosion.

The Job: Flushing and Bleeding a Focus

A brake fluid flush replaces all the old fluid in the reservoir, master cylinder, lines, ABS unit and calipers with fresh fluid of the correct spec. On a manual-transmission car, the clutch circuit should be bled at the same time so it gets fresh fluid too. Ford's guide states that systems should be flushed only with new fluid that is the same as the fluid required to fill the system.

A basic flush with a pressure bleeder or a two-person pedal method is a reasonable driveway job for someone who has done brakes before. Work from the wheel farthest from the master cylinder to the closest, keep the reservoir from running dry, and use fresh, sealed fluid. If air gets into the ABS hydraulic unit, a full bleed may require a scan tool that can cycle the ABS valves, and that is a shop job. Fill only to the MAX line; the guide notes that a level between MIN and MAX is within the normal range.

Keep the fluid clean. Ford warns that contamination with dirt, water, petroleum products or other materials may result in brake system damage and possible failure. Never use fluid from an old opened bottle, and do not use a funnel that has held oil.

What to Replace at the Same Time

A fluid flush is the natural time to look at the rest of the hydraulic system and the friction parts, since the wheels are off and the system is open:

• Brake pads. If your front pads are close to the wear limit, replace them before the flush so the reservoir level reads correctly afterward. For this car we carry Bosch front ceramic brake pads for the 2012-2018 Ford Focus and C-Max, and more options in our ceramic brake pads collection.
• Rotors. Pulsation or a lip at the rotor edge means rotors should go with the pads. See our brake rotors.
• Hoses. Rubber hoses with cracks or swelling should be replaced while the system is being bled. Browse brake hoses.
• Calipers. A caliper with a sticking piston or torn boot is a sign that moisture has done damage. Replace it now rather than bleeding the system twice. See brake calipers.
• Hardware. New clips and slide pin boots keep the new pads quiet. See brake hardware kits.

Depending on trim, a Focus may have rear drums or rear discs, so check which your car has before ordering rear parts.

Frequently Asked Questions

Can I use regular DOT 4 instead of DOT 4 LV in my Focus?

Ford specifies DOT 4 LV meeting WSS-M6C65-A2 and ISO 4925 Class 6 for the 2013-2018 Focus. A standard DOT 4 can be more than twice as thick at -40 C, which slows ABS and stability-control response in cold weather. Buy a fluid labeled DOT 4 LV or ISO 4925 Class 6.

Can I mix DOT 3 and DOT 4 LV?

Both are glycol-based, but mixing lowers the performance of the better fluid. On a 2013-2018 Focus, top off only with DOT 4 LV, and if the system has been topped with something else, a full flush restores the specified fluid.

Does the Focus manual transmission use brake fluid for the clutch?

Yes. The owner's guide lists "Brake fluid (and clutch fluid, if equipped)" with the same specification. The PowerShift automatic uses its own dual clutch transmission fluid, not brake fluid.

How much brake fluid does a Focus hold?

Ford does not publish a fill quantity in the owner's guide; it says to keep the level between MIN and MAX on the reservoir. For a full flush, have more than one bottle on hand so the reservoir never runs dry during bleeding.

My brake warning light is on but the reservoir looks fine. What now?

The red brake warning light also comes on for a brake system fault or when the parking brake is applied. If the parking brake is released and the light stays on, Ford advises having the system checked immediately.

Sources

1. 2012 Ford Focus Owner's Guide - DOT 3 PM-1-C, WSS-M6C62-A or WSS-M6C65-A1; brake and clutch share the fluid spec
2. 2014 Ford Focus Owner's Guide - DOT 4 LV PM-20, WSS-M6C65-A2 and ISO 4925 Class 6; warning lights; MIN/MAX check; scheduled maintenance and flushing guidance
3. 2017 Ford Focus Owner's Manual - DOT 4 LV PM-20 and WSS-M6C65-A2 for later model years
4. Motorcraft DOT 4 LV High Performance Brake Fluid (PM-20) product sheet - boiling points, -40 C viscosity, ABS/stability-control use, three-year service recommendation
5. 49 CFR 571.116, FMVSS No. 116 Motor Vehicle Brake Fluids - DOT 3 and DOT 4 dry and wet boiling points, viscosity limits, moisture labeling