2009 Nissan GT-R Brake Fluid Type and Flush Interval

By Core Brake Parts Tech Team — Circleville, OH warehouse

The 2009 Nissan GT-R takes Genuine NISSAN Brake Fluid R35 Special DOT4, which is the factory fill. Nissan's 2009 GT-R maintenance log calls for replacing it at 36 months, 60 months and 84 months, a time-based interval that works out to about every two years after the first change. If you drive the car hard, the owner's manual says to change it every 1,800 miles (3,000 km).

That short-interval rule surprises a lot of new R35 owners, so below we explain what the fluid spec means, why Nissan is so specific about it, how to read the two schedules, and what else to check when the fluid gets changed.

What brake fluid the 2009 GT-R uses

The 2009 GT-R owner's manual lists one brake fluid in its capacities chart and in its GT-R overview section: Genuine NISSAN Brake Fluid R35 Special DOT4. It is a DOT 4 glycol-based fluid, but Nissan does not treat it as just any DOT 4. The manual says the Vehicle Dynamic Control (VDC) unit and related parts were designed specifically for this fluid, and that Nissan cannot ensure the best performance and proper operation of the car if another brake fluid is used.

In practice, that means two things:

• For top-offs and routine changes, the fluid the manual names is the one that matches what the VDC and ABS hydraulics were calibrated with. If you want to stay exactly on the factory spec, use it.
• If you switch to another DOT 4, you are going outside Nissan's recommendation. At the very least, choose a fluid that meets the federal DOT 4 standard, flush the whole system so you are not running a mix of two formulas, and keep records in case the brakes are ever questioned under warranty or at resale.

Never put DOT 5 (silicone) fluid in this car. DOT 5 is chemically different from the glycol-based fluid the system was built around, and the manual only lists the R35 Special DOT4.

What DOT 4 actually means

"DOT 4" is a grade defined by Federal Motor Vehicle Safety Standard 116 (49 CFR 571.116). The standard sets minimum boiling points for new ("dry") fluid and for fluid that has absorbed a set amount of moisture ("wet"). Here is how the grades compare:

The gap between the dry and wet numbers explains why the GT-R's fluid has to be changed on a schedule even if the reservoir still looks full. Glycol brake fluid pulls moisture out of the air through the reservoir, seals and hoses. As the water content goes up, the boiling point goes down. On a car that can put a lot of heat into its brakes in a few hard stops, a lower boiling point means a greater chance of vapor forming in the caliper. You feel that vapor as a soft or sinking pedal right when you need the brakes most.

FMVSS 116 also requires every container of brake fluid to warn you to keep the fluid clean and dry and to keep the container tightly closed so it does not absorb moisture. Nissan's manual says the same thing in its own words: use only new fluid from a sealed container, because old, inferior or contaminated fluid can damage the brake system.

The flush interval: normal driving vs. performance driving

Nissan gives the 2009 GT-R two separate brake fluid rules. Which one applies depends on how you drive the car.

Normal driving: the maintenance log

The 2009 GT-R Service and Maintenance Guide lists "Replace brake fluid" at the 36,000 miles or 36 months, 60,000 miles or 60 months, and 84,000 miles or 84 months services. At most of those services, the item carries Nissan's mark meaning it is performed based on the number of months only. In other words, age is what triggers the fluid change, not mileage. A garage-kept GT-R that sees 3,000 miles a year still needs its fluid changed on the calendar, because the fluid absorbs moisture whether the car moves or not.

The same 60-month service also lists "Replace brake hoses." If your car is at or past five years old and the hoses have never been done, plan to do the hoses and a full fluid flush at the same time.

Performance driving: every 1,800 miles

Both the owner's manual and the maintenance guide include an "Additional Maintenance Items" section for performance driving. Nissan describes this as extended periods of high-rpm operation, frequent high pedal force braking from moderate and higher speeds, frequent throttle activation, and fast revving throughout the rpm range. When you drive that way, Nissan says to change the brake fluid, engine oil, transmission oil and front and rear differential oil every 1,800 miles (3,000 km) with the specified fluids. The same section also says to check fluid levels before driving.

If you take the car to track days or canyon runs, the 1,800-mile rule is the one that applies to you. Many owners also bleed the calipers before every track event, because a single hot session can boil fluid that has already absorbed moisture.

Checking the level and reading the warning light

The brake fluid reservoir is under the hood (the owner's manual shows it as item 5 in the engine compartment diagram). The level should sit between the MAX and MIN lines. Nissan recommends checking fluid levels as often as possible, or at least whenever you refuel.

• Level below MIN or the brake warning light on: The manual says to top up with R35 Special DOT4 to the MAX line. It also says that if the level is below MIN, you should not drive until the brake system has been checked by a GT-R certified Nissan dealer.
• Needing to add fluid often: This is not normal. Fluid slowly drops as the pads wear, but if you keep adding fluid, something is leaking and needs to be found.
• Brake warning light with the parking brake off: The same light warns of low brake fluid. If the light and the ABS warning light come on together and the fluid level is correct, the manual says the ABS may not be working properly. Have it checked promptly and avoid high-speed driving and abrupt braking until then.

When you open the reservoir, clean the cap first so dirt cannot fall into the fluid. Keep rags handy, because brake fluid damages paint. If you spill any, wash it off with water right away.

Symptoms of old or contaminated fluid

Old fluid rarely causes a sudden failure on the street. More often, it gradually makes the pedal feel worse. Watch for:

• A pedal that feels softer or travels farther after a few hard stops, then firms up once the brakes cool. This is the classic sign that the fluid's boiling point has dropped.
• Fluid in the reservoir that has turned noticeably darker than new fluid. Color alone is not a moisture test, but dark fluid on a car past its interval should be changed.
• No record of a fluid change within the last two to three years, especially on a used GT-R. Assume the fluid is due unless there is a receipt that says otherwise.

Other problems can cause a spongy pedal too, including air in the lines, a leaking hose or a failing master cylinder. If a fresh flush does not restore a firm pedal, have the whole hydraulic system inspected.

What to do at the same time

A fluid flush is a good time to look over the rest of the brake system:

• Pads and rotors: The GT-R uses what Nissan calls a high performance brake system, with cross-drilled floating rotors and radial-mounted six-piston monoblock calipers. Nissan says to replace brake pads and disc rotors as a set, and to replace all four sets at the same time to keep braking at its best. The manual also warns that frequent hard braking can scorch the pads, which means they may need to be replaced before they reach the wear limit. If yours are due, see our DBA 5000 Series XS two-piece front rotor for the 2009+ GT-R R35, or browse brake rotors and brake pads.
• Brake hoses: Nissan lists hose replacement at 60 months. Rubber hoses age with time and heat, and many track owners switch to braided lines. See brake hoses and brake lines.
• Wear indicators: The pads have audible wear indicators. A high-pitched scraping sound that first appears only when braking, and then all the time, means the pads are due.

Some R35 brake noises are normal. The manual explains that the pad-to-caliper gap is larger than usual, so the pads can rattle lightly over bumps. The rotors can also make a rumbling noise when hot until they cool down. Neither noise is a fluid problem.

How hard is the job?

The flush itself is the same work as on any car. You remove the old fluid from the reservoir, then bleed each caliper in turn with new fluid until clean fluid comes out, keeping the reservoir from running dry. On the GT-R, a few things make it more demanding:

• The calipers are large multi-piston monoblock units. Find every bleed screw on each caliper and bleed them in the order the factory service manual gives.
• The VDC/ABS hydraulic unit was designed around the specified fluid. If air gets into that unit, follow the factory service manual's procedure for it. This is one reason Nissan points owners to a GT-R certified dealer for brake work.
• The car's warranty and GT-R Performance Optimization services were tied to certified dealers. Keep receipts for any brake work you do yourself.

A careful DIYer with a pressure or vacuum bleeder can do a routine flush. If the pedal feels different afterward, or an ABS or VDC light comes on, stop and have the system checked before you drive the car hard.

Frequently Asked Questions

Can I use any DOT 4 brake fluid in a 2009 GT-R?

Nissan specifies Genuine NISSAN Brake Fluid R35 Special DOT4 and says it cannot ensure the best performance and proper operation of the car with any other fluid, because the VDC unit and related parts were designed for it. Any substitute should at least meet the FMVSS 116 DOT 4 standard, and the whole system should be flushed, not just topped off, so you are not running a mix of fluids.

How often should I flush the brake fluid if I only drive on the street?

The 2009 maintenance log lists brake fluid replacement at 36, 60 and 84 months, based on time rather than mileage. That is about every two years after the first change at three years.

Why does Nissan say 1,800 miles?

The 1,800-mile (3,000 km) interval applies to performance driving: extended high-rpm use and frequent hard braking from moderate and higher speeds. That kind of use heats the fluid more and uses up its boiling-point margin faster, so Nissan shortens the interval for brake fluid along with the engine, transmission and differential oils.

Is DOT 5 fluid an upgrade because it has a higher boiling point?

No. DOT 5 is silicone-based and is not what this system was designed for. The 2009 GT-R calls for a DOT 4 glycol fluid only.

My brake warning light is on but the parking brake is off. Can I drive?

First check the reservoir. If the fluid is below MIN, the manual says not to drive until the brake system has been checked. If the level is correct and the ABS light is also on, have the ABS checked promptly and avoid high-speed driving and abrupt braking until then.

Should I replace pads and rotors when I flush the fluid?

Only if they are worn or heat-damaged. When they do need replacing, Nissan says to replace pads and rotors as a set and to do all four corners at the same time.

Sources

1. 2009 Nissan GT-R Owner's Manual (Nissan USA) - R35 Special DOT4 fluid spec, VDC caution, 1,800-mile performance-driving fluid change, reservoir MAX/MIN check, warning light behavior, brake system and pad notes
2. 2009 Nissan GT-R Service and Maintenance Guide (Nissan USA) - brake fluid replacement at 36, 60 and 84 months (time-based), brake hose replacement at 60 months, Schedule 1 and 2 definitions
3. 49 CFR 571.116, FMVSS No. 116 Motor Vehicle Brake Fluids (Cornell LII) - DOT 3/4/5 dry and wet boiling point minimums, -40 C viscosity limits, container moisture warnings