2003-2011 Lincoln Town Car Brake Fluid Type and Flush Interval

By Core Brake Parts Tech Team — Circleville, OH warehouse

The 2003-2011 Lincoln Town Car uses DOT 3 brake fluid. Ford's owner guide calls for Motorcraft High Performance DOT 3 Motor Vehicle Brake Fluid (part PM-1 or PM-1-C) meeting Ford specification ESA-M6C25-A or WSS-M6C62-A, and says DOT 4 can be used if DOT 3 is not available. Ford's normal maintenance schedule for the Town Car does not list a fixed brake fluid change interval; it calls for regular brake inspections instead, so the practical answer is to flush when a test or inspection shows the fluid is worn out, and sooner on livery cars.

What Brake Fluid the Town Car Takes

The third-generation Town Car (the 2003 refresh through the end of production in 2011) shares one brake fluid requirement across its run. The 2006 Town Car Owner's Guide lists it in two places: the refill capacities table and the lubricant specifications table.

Ford's footnote is worth reading closely: use only brake fluids certified to meet Ford specifications. In practice that means a DOT 3 fluid from a reputable maker, sealed, fresh from the bottle. The guide's engine-compartment diagram for the 4.6L SOHC V8 shows the brake fluid reservoir in the engine bay, and the guide's symbol glossary identifies brake fluid as non-petroleum based.

Can you use DOT 4 or DOT 5.1?

Ford explicitly allows DOT 4 when DOT 3 is not available. DOT 3, DOT 4 and DOT 5.1 are all glycol-based fluids, and the federal brake fluid standard (FMVSS 116) sets their minimum boiling points: DOT 3 must have a dry boiling point of at least 205 C (401 F) and a wet boiling point of at least 140 C (284 F); DOT 4 must reach 230 C (446 F) dry and 155 C (311 F) wet. So DOT 4 is a step up in heat tolerance, not a compromise. DOT 5.1 is not mentioned in the Town Car guide, so stick with DOT 3 or DOT 4.

Never use DOT 5 silicone

DOT 5 is silicone-based. The federal standard requires it to be dyed purple so it is easy to tell apart, while DOT 3, 4 and 5.1 range from colorless to amber. Silicone fluid is not what the Town Car's system was designed around and it does not mix with glycol fluid. If you ever see purple fluid in a Town Car reservoir, someone put the wrong fluid in and the system needs to be fully flushed.

What Ford's Maintenance Schedule Actually Says About Flushing

This is where most owners get confused. Ford's 2006 and 2010 Scheduled Maintenance Guides both place the Town Car on the Normal Schedule for Cars, and neither lists a brake fluid replacement at any mileage for it. What the schedule does list:

• Normal driving: inspect brake pads, rotors, brake lines and hoses and the parking brake system every 15,000 miles. The 2010 guide also recommends checking and topping up the brake fluid level at every multi-point inspection.
• Livery, taxi and heavy commercial use: inspect the brake system every 5,000 miles. The 2010 guide lists Executive Series Town Cars equipped with an engine idle hour meter under this same severe schedule.
• The only fixed fluid interval in the book: the Exceptions page lists changing brake fluid every two years, but only for Class A motorhome chassis, not for cars.

So Ford did not set a calendar interval for Town Car brake fluid. That does not mean the fluid lasts forever. It means Ford leaves the call to inspection, which is how a good shop should treat it.

Why Brake Fluid Wears Out

Glycol brake fluid absorbs moisture. The federal standard requires every DOT 3 and DOT 4 container to carry the warning to keep the container clean and tightly closed to prevent absorption of moisture, and to store the fluid only in its original container. The same thing happens slowly inside the car through the reservoir cap and hoses.

Water in the fluid does two things. First, it drops the boiling point toward the wet boiling point numbers above. A heavy Town Car coming down a long grade, or a livery car making stop after stop, can heat the calipers enough to boil old fluid, which puts vapor in the lines and gives you a soft or sinking pedal. Second, moisture promotes corrosion in the calipers, the brake lines and the ABS hydraulic unit, which are far more expensive to replace than a bottle of fluid.

The Town Car has a four-wheel anti-lock brake system, so the fluid also runs through the ABS modulator valves. Keeping that fluid clean is cheap insurance for one of the costliest parts of the brake system.

When to Flush a Town Car's Brake Fluid

Since Ford gives no fixed interval, use condition and use case:

• Test it at every brake inspection. Brake fluid test strips or an electronic moisture tester give a real reading instead of a guess. Fluid that tests high for moisture or copper content should be replaced.
• Look at it. New DOT 3 is colorless to amber. Fluid that has turned dark brown or has debris in the reservoir is overdue.
• Flush whenever the system is opened. Replacing a caliper, brake hose or master cylinder lets air and moisture in. Bleeding the whole system at that point costs little extra.
• Shorten the gap on livery and airport cars. Ford already puts these on a 5,000 mile brake inspection. High stop counts mean more heat cycles, so test the fluid at each of those inspections.
• If the history is unknown, as with most used Town Cars today, flush it once and start a record.

Symptoms That Point to Fluid Problems

• Red BRAKE warning lamp with the parking brake released. Ford's owner guide says this indicates low brake fluid and the brake system should be inspected immediately. Low fluid usually means worn pads or a leak, not evaporation.
• Soft or spongy pedal that firms up with pumping: air or boiled fluid in the lines.
• Pedal that fades on long downhill runs and recovers after cooling: classic sign of wet, low-boiling-point fluid.
• Dropping fluid level. The guide notes the level drops slowly as the brakes wear and rises when brake components are replaced. A slow drop between pad changes is normal; a noticeable drop in weeks is a leak.

Do not just top off a low reservoir and forget it. Ford says levels below MAX that do not trigger the warning lamp are in the normal range. If the level drops below that, find out why before adding fluid.

What to Replace at the Same Time

A fluid flush is the natural time to look at the rest of the hydraulic system. Check the rubber brake hoses at each wheel for cracking or bulging and replace any that are soft; our replacement brake hoses are the usual fix. If a caliper piston is sticking or a bleeder screw is seized, replacement brake calipers save a lot of frustration. And if the pads are close to the wear limit, doing them together means you only bleed once. The 2003-2011 Lincoln Town Car front and rear brake kit covers pads and rotors on both axles, or browse all brake pads and brake rotors.

How hard is the job?

A basic gravity or two-person bleed on a Town Car is a driveway job for a careful owner with a line wrench, clear tubing and a catch bottle. Start at the wheel farthest from the master cylinder and work toward the closest, keep the reservoir from running dry, and use only fresh fluid from a sealed bottle. If air gets into the ABS hydraulic unit, a full bleed may need a scan tool to cycle the ABS valves; follow the factory service manual procedure in that case. Brake fluid damages paint, so cover the fender and wipe up spills right away.

Frequently Asked Questions

What type of brake fluid does a 2003-2011 Lincoln Town Car use?

DOT 3. Ford specifies Motorcraft High Performance DOT 3 Motor Vehicle Brake Fluid, part PM-1 or PM-1-C, meeting Ford specification ESA-M6C25-A or WSS-M6C62-A.

Can I put DOT 4 in my Town Car?

Yes. Ford's owner guide says DOT 3 is recommended, but DOT 4 can be used if DOT 3 is not available. DOT 4 has higher minimum boiling points under the federal standard.

How often should Town Car brake fluid be changed?

Ford's normal schedule for the Town Car does not list a fixed brake fluid change interval. It calls for brake inspections every 15,000 miles in normal use and every 5,000 miles in livery or taxi use. Test the fluid at those inspections and replace it when it shows moisture or contamination, or whenever the hydraulic system is opened.

How much brake fluid does a Town Car hold?

Ford does not publish a volume for the Town Car. The owner guide simply says to fill to the line on the reservoir. For a full flush, have more than one sealed bottle on hand so you never run short mid-bleed.

Why is my BRAKE light on after I release the parking brake?

Ford's owner guide says that indicates low brake fluid and the brake system should be inspected immediately. Check for worn pads and leaks at the calipers, hoses and master cylinder before driving further.

Is it safe to mix brands of DOT 3 fluid?

The simplest rule is to top off with the same type already in the system: a DOT 3 (or DOT 4) glycol fluid certified to Ford specifications, from a sealed bottle. Never add DOT 5 silicone fluid, which is dyed purple. If you do not know what is in there, a full flush removes the question.

Sources

1. Ford Motor Company - 2006 Lincoln Town Car Owner's Guide - brake fluid type, Ford part numbers and specs, DOT 4 allowance, fill to reservoir line, fluid level behavior, brake warning lamp, four-wheel ABS
2. Ford Motor Company - 2006 Scheduled Maintenance Guide - Town Car on the car schedule, 15,000 mile brake inspection, 5,000 mile inspection for livery and taxi use, two-year brake fluid change listed only for Class A motorhomes
3. Ford Motor Company - 2010 Scheduled Maintenance Guide - brake fluid level check at multi-point inspection, severe schedule including Executive Series Town Car with idle hour meter
4. 49 CFR 571.116 (FMVSS 116) via Cornell Legal Information Institute - DOT 3 and DOT 4 dry and wet boiling point minimums, moisture warning label, DOT 5 purple color requirement