2004-2012 Mitsubishi Galant Brake Fluid Type and Flush Interval

By Core Brake Parts Tech Team — Circleville, OH warehouse

The 2004-2012 Mitsubishi Galant uses DOT 3 or DOT 4 brake fluid. Mitsubishi's owner's manual says to use fluid "conforming to DOT 3 or DOT 4," and the factory workshop manual lists the same spec for the caliper overhaul. Change it on a time basis rather than waiting for a problem: test the fluid at every brake job and flush it whenever the test fails or the fluid has turned dark.

What Fluid the Galant Takes, and Why DOT 4 Is the Smart Pick

The ninth-generation Galant (the 2004 through 2012 cars) is a four-wheel disc car. Mitsubishi's service diagrams show a front disc brake and a rear disc brake fed by a master cylinder on a vacuum brake booster, with either a hydraulic unit integrated with the ABS-ECU on ABS cars or proportioning valves on cars without ABS. Everything in that system is built for glycol-based DOT 3 or DOT 4 fluid.

Both grades are legal for the car. The difference is heat tolerance. The federal brake fluid standard (FMVSS 116) sets these minimum boiling points:

"Wet" boiling point is the number that matters in real life. It is measured after the fluid has absorbed moisture, which is exactly what happens to fluid sitting in a Galant for a few years. DOT 4 starts higher and stays higher once it is wet, so if you tow a small trailer, drive in the mountains or just brake hard, DOT 4 gives you more margin before the pedal goes soft. For a daily driver, a quality DOT 3 still meets the spec.

Do not use DOT 5. It is silicone-based, it is not a fluid Mitsubishi lists for this car, and it does not mix with the glycol fluid already in the lines and ABS unit. DOT 5.1 is a glycol fluid, but it is not what the manual names either, so there is no reason to use it on a Galant.

Where to Check It and What the Marks Mean

The brake fluid reservoir sits on top of the master cylinder at the back of the engine bay, in front of the brake booster; the engine compartment diagram in the owner's manual labels it. The level must stay between the MAX and MIN marks on the side of the reservoir.

Mitsubishi makes a point worth knowing: the level drops slightly as the brake pads wear, and that is normal. As pads get thinner the caliper pistons move out, and fluid moves from the reservoir into the calipers to fill that space. So a level that has crept down toward MIN on a car with worn pads is telling you about the pads, not a leak. Do not top it off to MAX on worn pads; when new pads go in and the pistons are pushed back, that extra fluid has nowhere to go and can overflow.

What is not normal is a level that falls markedly in a short time. The manual says that points to a leak somewhere in the system and the car should be checked before it is driven much further.

Signs Your Galant's Brake Fluid Needs Attention

• Red brake warning light on while driving. On the Galant this light comes on with the parking brake lever set, when the fluid in the reservoir falls to a low level, or when the brake circuit is not operating correctly. If it stays on with the lever fully released, stop somewhere safe and check the reservoir.
• Soft or sinking pedal, especially after hard stops. Moisture-laden fluid can boil in a hot caliper and form vapor, and vapor compresses where fluid does not.
• Dark fluid. Fresh DOT 3 and DOT 4 are colorless to amber by federal rule. Fluid that looks like coffee is contaminated and worn out.
• A failed test strip or meter reading. This is the most objective check and takes a minute at the reservoir.
• ABS light plus a brake light together. Low fluid or a hydraulic fault can trigger both; check the level first, then have the codes read.

How Often to Flush It

Brake fluid wears out with time, not miles. Glycol fluid pulls moisture from the air through hoses, seals and the reservoir cap, and Wagner's technical team notes that the absorbed water both lowers the boiling point and leads to corrosion inside the lines and hydraulic parts. That is why a Galant that sits a lot still needs fresh fluid.

Wagner recommends judging fluid by its copper content: as the corrosion inhibitors in the fluid are used up, copper from the brake lines dissolves into it, and they say the fluid should be changed when copper reaches 200 ppm or more. Inexpensive test strips read that directly. They also note the change interval can be shorter in humid climates, and cars that tow or work hard should have the fluid tested more often.

For the exact time or mileage interval on your specific Galant, follow the maintenance schedule in the Mitsubishi warranty and maintenance booklet that came with the car, and treat it as a maximum. On a car this age, the practical rule is simple: test the fluid every time the wheels come off for pads or rotors, and flush it any time it fails the test, looks dark, or has an unknown history.

How the Job Goes on a Galant

A flush on this car is a normal driveway job for someone with basic tools, a helper and a clear hose into a catch bottle.

1. Pull as much old fluid out of the reservoir as you can with a clean suction tool and refill with fresh DOT 3 or DOT 4 from a sealed bottle.
2. Bleed each wheel in the order the factory service manual gives for your car, pushing fresh fluid through until it comes out clean and bubble-free. Keep the reservoir from running dry the whole time, or you will pull air into the master cylinder and, on ABS cars, possibly the hydraulic unit.
3. Tighten the bleeder screws to the value in the factory service manual; they are small and snap easily.
4. Finish with the level between MAX and MIN, the cap sealed tight, and a firm pedal before the car moves.

Mitsubishi's handling rules from the owner's manual apply here: keep any petroleum-based fluid (engine oil, power steering fluid, parts cleaner residue) out of the brake system because it damages the rubber seals, do not mix brands of brake fluid, keep the cap closed so the fluid does not absorb moisture or evaporate, and wipe up spills right away because brake fluid damages paint.

If the reservoir was ever run dry or air reached the ABS unit, a manual bleed may not clear it. That is a job for a shop with a scan tool that can cycle the ABS pump.

What to Replace While You Are In There

A flush is the perfect time to look at the rest of the system, because you are at every wheel anyway:

• Pads and rotors. If pads are near the wear limit, do them first, then flush, so the reservoir level is set with pistons in their new position. Our 2004-2012 Mitsubishi Galant front and rear brake kit covers rotors and pads at all four corners of this four-wheel disc car.
• Rubber brake hoses. Cracked, swollen or seeping hoses let moisture in and make a soft pedal. See our brake hoses.
• Calipers. A seized bleeder, a torn boot or a piston that will not retract is a sign the caliper is done. Browse brake calipers.
• Hardware. Fresh clips and slide pin boots keep pads from dragging; see brake hardware kits.

If the fluid came out full of dark sludge, or the pedal still sinks slowly at a stop after a good bleed, the master cylinder seals may be bypassing internally. That calls for a replacement master cylinder rather than another flush.

Frequently Asked Questions

Can I mix DOT 3 and DOT 4 in my Galant?

Both are glycol-based and both are approved for the car, so they are chemically compatible. Mitsubishi's owner's manual does say not to mix brands because additives differ, so the cleanest approach is to flush and fill with one brand and one grade.

Should I switch my Galant to DOT 4?

It is a reasonable upgrade. DOT 4 is on the approved list, and its minimum wet boiling point is higher than DOT 3's, which gives more fade margin on hot, hard stops. Just do a complete flush when you switch rather than topping off.

Why is my brake fluid low if there is no leak?

Pad wear. As pads thin, the caliper pistons move out and fluid follows them from the reservoir. Mitsubishi notes that this slight drop is normal. A fast drop, or wet spots at a wheel or under the master cylinder, is a leak.

Is silicone DOT 5 fluid better for my Galant?

No. It is not a fluid Mitsubishi lists for this car and it should not be mixed with the glycol fluid in the lines and ABS unit. Stick with DOT 3 or DOT 4.

How do I know when the fluid is worn out?

Use a copper test strip at the reservoir. Wagner's guideline is to change fluid once copper reaches 200 ppm. Dark color and a soft pedal after hard use are other clues, but the strip is the objective answer.

Does the brake warning light mean I am low on fluid?

It can. On the Galant the same red light covers the parking brake being applied, low fluid in the reservoir, and a brake circuit fault. Release the lever fully, then check the fluid level. If the level is fine and the light stays on, have the system inspected.

Sources

1. Mitsubishi Galant Owner's Manual, Vehicle care and maintenance 7-14 - DOT 3 or DOT 4 spec, MAX/MIN marks, pad-wear level drop, no petroleum fluids, do not mix brands
2. Mitsubishi Galant Owner's Manual, Features and controls 3-78 - brake warning light conditions
3. Mitsubishi Galant 2004 Workshop Manual, brake section - DOT3 or DOT4 for caliper service, vacuum booster, proportioning valves
4. Mitsubishi Galant 2004 Workshop Manual, brake system layout - front and rear disc brakes, ABS hydraulic unit integrated with ABS-ECU
5. 49 CFR 571.116, FMVSS 116 Motor vehicle brake fluids - DOT 3/4/5 dry and wet boiling points, fluid color
6. Wagner Brake: When to Change Brake Fluid - moisture absorption, corrosion, 200 ppm copper change point, humid-climate note