2011-2019 Ford Fiesta Brake Fluid Type and Flush Interval

By Core Brake Parts Tech Team — Circleville, OH warehouse

The 2011-2019 Ford Fiesta does not use a single brake fluid across every year. The 2011 owner's guide calls for Motorcraft High Performance DOT 3 fluid (PM-1-C, Ford spec WSS-M6C62-A or WSS-M6C65-A1). The 2019 owner's manual calls for Motorcraft DOT 4 LV High Performance fluid (PM-20, Ford spec WSS-M6C65-A2). Ford's US maintenance schedule has no fixed flush mileage. It only calls for a brake system inspection every 10,000 miles or 12 months. Ford's own spec sheet for the DOT 4 LV fluid recommends changing it every three years.

Which Brake Fluid Your Fiesta Takes, by Year

Ford changed brake fluid specs during this generation. Do not assume a 2011 and a 2019 Fiesta take the same bottle. Here is what Ford's own owner manuals print for the two ends of the run:

For the years in between, check two places before you buy fluid. First, look at the printing on the reservoir cap. Second, look at the Capacities and Specifications chapter of the owner's manual for your exact year. Ford's warning in the 2019 manual is blunt: using any fluid other than the recommended one reduces braking efficiency and can lead to loss of vehicle control. The 2011 guide lists the Ford spec numbers, not just "DOT 3", so match the spec, not only the DOT rating.

What DOT 3, DOT 4 and DOT 4 LV Actually Mean

The DOT number refers to the federal brake fluid standard, FMVSS 116. The standard sets a minimum boiling point for fresh fluid (dry) and for fluid that has absorbed a controlled amount of moisture (wet):

The "LV" in DOT 4 LV stands for low viscosity. Ford's data sheet for PM-20 says it meets ISO 4925 Class 6, with a maximum kinematic viscosity of 750 mm2/s at -40 F. That is far thinner in the cold than the DOT 4 ceiling. Ford says the thinner fluid gives faster brake response at low temperatures, and it is designed for vehicles with ABS and stability control. Ford lists PM-20 at a 500 F dry boiling point and a 338 F wet boiling point. Both numbers are well above the DOT 4 minimums.

The wet boiling point is the number that matters as the car ages. Brake fluid is glycol-based and pulls moisture out of the air. As water builds up, the boiling point drops toward the wet figure. On a long downhill or a hard stop from speed, low-boiling fluid can vaporize in the calipers, and the pedal goes soft. That is why the federal standard requires this label text on every bottle: keep the fluid clean and dry, store it only in its original container, and keep the cap tight.

How Often to Flush a 2011-2019 Fiesta

This is where owners get confused. Ford's scheduled maintenance tables for the Fiesta (we checked the 2015 and 2019 US schedules) have no line item for replacing brake fluid. What they do call for, every 10,000 miles or 12 months, is to inspect the brake pads, shoes, rotors, drums, linings, hoses and parking brake. The special operating conditions tables change the oil and transmission intervals, but they do not add a brake fluid change.

Ford's own fluid division does give a number. The product page for Motorcraft DOT 4 LV (PM-20) says the recommended service, or change-out interval, is every three years. That is the most useful Ford figure for a Fiesta on DOT 4 LV, and it is a sensible target for the DOT 3 cars too, since DOT 3 starts with the lower wet boiling point. Flush sooner if:

• The fluid in the reservoir has gone from clear or amber to dark brown.
• The pedal feels softer after repeated hard stops, then firms up after it cools.
• You drive a Fiesta ST hard on back roads or at track days, where caliper temperatures run far higher than commuting.
• You have just replaced a caliper, hose or master cylinder and opened the system.

Symptoms of Low or Worn-Out Fluid

The Fiesta tells you when the level is low. In the 2019 manual, a red "Brake fluid level low" message means the level is low or there is a brake system fault, and Ford says to have the car checked immediately. The red brake warning lamp works the same way. If it stays on after you release the parking brake, it indicates low brake fluid or a brake system fault.

Keep in mind that the level drops slowly as the pads wear. Ford's 2011 guide explains that the level falls as brakes wear and rises when new brake parts are installed. A level between MIN and MAX is normal, and Ford says there is no need to add fluid. A level below MIN is not something to just top off and forget. It usually means very worn pads or a leak at a caliper, hose, line or the master cylinder. Find the cause.

Old fluid rarely triggers a warning light. The signs are a spongy or long pedal, a pedal that fades after several hard stops, and dark fluid in the reservoir. Corrosion inside the system from wet fluid can also cause sticking caliper pistons over time.

Manual Transmission Fiestas: The Clutch Shares the Reservoir

If your Fiesta has a manual gearbox, including every Fiesta ST, the clutch hydraulics run off the brake fluid reservoir. Both the 2011 guide and the 2019 manual say this plainly: the brake and clutch systems share the same reservoir. Two things follow from that:

• A leak at the clutch master or slave cylinder will drop the brake fluid level and can trigger the brake warning.
• A complete fluid change on a manual car means bleeding the clutch slave as well as all four brakes. Otherwise old fluid stays in the clutch circuit.

Automatic Fiestas use a dual clutch transmission that takes its own Motorcraft dual clutch transmission fluid. That fluid is separate from the brake system and is never a substitute.

Doing the Flush: Difficulty and What to Replace at the Same Time

A brake fluid flush on a Fiesta is a moderate DIY job with a helper or a pressure bleeder. The basic order is to bleed each wheel, starting with the one farthest from the master cylinder, until clean fluid comes through, while never letting the reservoir run dry. Ford's 2019 manual warns that letting the fluid level fall outside its normal range can compromise the system. Use fluid only from a freshly opened, sealed container, and do not let it touch paint or skin.

ABS-equipped cars can trap old fluid in the hydraulic unit. Many shops run the ABS pump with a scan tool during the bleed to push it out. If the pedal is still soft after a careful bleed, that is the likely reason. Have it bled with the proper tool instead of guessing.

Because you are already opening every bleeder, a flush is the right time to handle the parts that share the job:

• Pads and rotors. If the pads are near the wear limit, replace them first, then flush. That way the reservoir level is right for new pads. See our brake pads and brake rotors. For the Fiesta ST, the Hawk HP Plus front pads for the 2014-2016 Fiesta ST are a spirited-driving compound. The EBC BSD V-slot front rotor pair for 2013-2019 Fiesta is a slotted upgrade.
• Brake hoses. Cracked or swollen rubber hoses add pedal softness that no amount of bleeding fixes. Our brake hoses collection covers replacements.
• Bleeder screws. Seized bleeders are the most common thing that turns a one-hour job into a caliper replacement. If one snaps, see brake calipers.
• Track-driven ST cars. Owners who run a Fiesta ST at track days should flush before each event season. A bigger brake package such as the Wilwood Dynapro 6 front big brake kit for 2011 and newer Fiesta adds thermal capacity, but it still depends on fresh fluid.

Torque the bleeder screws and wheel lug nuts to the values in the factory service manual. Pump the pedal to a firm feel before moving the car.

Frequently Asked Questions

Can I put DOT 3 in a Fiesta that calls for DOT 4 LV?

No. Ford's manual for the DOT 4 LV cars says to use only the recommended fluid, and that any other fluid may reduce braking efficiency. DOT 3 has a lower minimum boiling point and does not meet the low-viscosity requirement of WSS-M6C65-A2.

Is DOT 5 brake fluid OK for a Fiesta?

No. DOT 5 is silicone-based and dyed purple under the federal standard. No Fiesta in this range lists it. Do not confuse it with DOT 5.1, which is glycol-based. Ford's PM-20 data sheet specifically says not to use PM-20 in vehicles that call for a DOT 5.1 spec. Use exactly the spec your manual lists.

Does Ford require a brake fluid change on the Fiesta?

The US scheduled maintenance tables we checked only require a brake system inspection every 10,000 miles or 12 months. Ford's Motorcraft data sheet for DOT 4 LV recommends a change every three years. That is the interval we recommend following.

Why does my brake fluid level keep dropping?

Some drop is normal as pads wear. A steady drop, or a level below MIN, points to a leak. On manual-transmission Fiestas, that includes the clutch master and slave cylinders because they share the reservoir.

How much brake fluid does a Fiesta flush take?

Ford does not list a flush volume in the owner's manual. It only specifies filling between the MIN and MAX lines. Buy more than you think you need in sealed bottles, and open a fresh one rather than reusing a half-used container, since opened fluid absorbs moisture.

Sources

1. Ford Motor Company - 2019 Fiesta Owner's Manual - PM-20 DOT 4 LV / WSS-M6C65-A2 spec, brake fluid warnings, shared clutch reservoir, warning lamp and message meanings, 10,000-mile/12-month brake inspection
2. Ford Motor Company - 2011 Fiesta Owner's Guide - PM-1-C DOT 3 / WSS-M6C62-A or WSS-M6C65-A1 spec, shared brake/clutch reservoir, level drops with pad wear
3. Ford Motor Company - 2015 Fiesta Normal Scheduled Maintenance - no fixed brake fluid change interval; brake inspection every 10,000 miles or 12 months
4. Ford Chemicals and Lubricants - DOT 4 LV High Performance Brake Fluid - three-year change-out interval, ISO 4925 Class 6, 500 F / 338 F boiling points, 750 mm2/s viscosity, do not use in DOT 5.1-spec vehicles
5. 49 CFR 571.116 (FMVSS 116) Motor Vehicle Brake Fluids - DOT 3 and DOT 4 minimum dry and wet boiling points, viscosity limits, container label warnings, DOT 5 color