brake fluid recommendations
 

as i was cleaning my engine bay the other day i notice brake fluid was runing low
tried doin a search but all i found is recommendatiosn for racing brake fluid(ie motul/endless)

besides those anyone recomened something i can buy at autozone/pepboys?
car is mainly street/canyons

*or should i just buy nissan brake fluid to be on the safe side?

thanks

I heard motul RBF 600 is good, as I'll probably get that brand when I switch to SS brake lines. Anyone know how many bottles I'll need? How Long it will last?

if i buy the motul is it safe to mix it with the current fluid on the resevoir as a temporary fill?

Well since I will have to drain the current fluid when I change the brake lines, everything will work out & be new.

i think stock is Dot 3 fluid. so u cant mix it with DOT 4.

The fluid level drops as the brake pads wear, which is normal. Check your pads before filling the reservoir.

I recommend AP Racing Formula 5.1 fluid for street and light track use. AP600 for serious track work.

Chris

Dot 4 is Dot 3 compatible, it's basically just a higher spec of Dot 3.

OO sorry, nvm then

Amsoil Series 600 DOT 4. Its going in mine once I switch pads.

http://www.amsoil.com/StoreFront/ima...rake-Fluid.jpg

I just supplied a Time Attack team with a bunch of this stuff.

DOT 4 has a significantly higher cold viscosity than DOT 3 and is not as compatible with ABS in cold climates. If you are going to be in an area where temps get low, I'd go with Motul DOT 5.1 as it has a thinner viscosity for keeping the ABS happy and has very good boiling point stats. It also wont need to be changed as often as racing brake fluid.

To answer your question as to something you can buy at the local auto parts store, for street use, and even occassional light track use, I recommend Valvoline Synthetic. Its a great fluid with a relatively high boil point, and what I put in all of my customers cars when I do brake swaps for them. Until this car, its what I always used when tracking my 350z and C6 also, with no problems and a much lower cost than all the fancy stuff.

Now I use Brembo fluid. Its as good as the others, and just slightly cheaper where I get it from.

Castrol SRF if you track your car

+1 on SRF. But yes, complete overkill if you only drive on the street.

Although, 90% of the crap (sorry, I mean mods) that members bolt onto their cars are complete overkill...

yup, 2 piece rotor, etc.

True, but would it not be safer and bring piece of mind that no matter what you can throw at your car, every part will be up to the task and more? At least that is how I rationalize a lot of modding haha.

Is there a concern about the age of brake fluid? I've got an unopened, sealed bottle of Motul thats been sitting on my shelf for I don't know how long. Was going to use it to flush my clutch but wanted to tap the expertise on here first to see if I'd be wasting my time with it.

if you have an unlimited budget, sure why not.

i might be in the minority, but i like to save money where it makes sense. i wont spend money on rotoros and rims, but i will gladly spend it on tires, brake pads and synthetic oil

If you read the label on most DOT4 fluids, it will tell you that you can mix DOT4 with DOT3. You might as well do it right the first time and flush your system with DOT4 brake fluid. If you're careful, you should be able to drain, flush and bleed with new DOT4 and use 2 quarts. Don't use DOT5...that is silicone based and is not compatible with ABS brakes. DOT4 is fine with ABS. DOT4 has a higher boiling point than DOT3, and therefore is more performance oriented. Likely overkill for most, especially if your car remains on the street 100% of the time, but if you want to splurge a little it doesn't hurt. Keep in mind, some luxury brands put DOT4 in their vehicles from the factory, eg. BMW, Mercedes-Benz.

In my opinion, if you can afford a good quality DOT4 go for it. If not, a "house brand" DOT4 is likely better than a DOT3 fluid.

Should be OK, if it is still sealed. If it is a previously opened bottle, you need to worry about exposure to dust, contaminants and moisture, all of which could lower the boiling point of the brake fluid...obviously not good.

most performance shops recommend motul 600... it's not cheap but it's worth the price

That is why they recommend it.

For 99.9% of drivers, the valvoline synthetic will be good enough.

Actually, the opposite is more likely true. The manufacturing process is the key to high-quality fluid. There are only a handful of chemical plants in the world equipped to make glycol ester-based brake fluid. Every label you see on the market comes from one of them. However, there are major differences in how the product is specified and what type of packaging process is used.

The better (more expensive) fluids on the market are packed in nitrogen, not air like some of the cheaper stuff. This means that the better fluids are actually "dry" when you crack the seal on the bottle. The cheaper fluids have already pulled whatever moisture they could out of the air they were packaged in, lower their boiling point efficacy. The cheap DOT4 stuff may have passed the SAE tests, but the product actually sitting on a store shelf may not have the exact same properties as what was tested in the lab.

Also, the more expensive fluids are typically more dense, meaning they have less dissolved air trapped in suspension. The more dense the fluid is (higher specific gravity), the better the brake pedal feels. Specifying a denser fluid adds production costs since it takes more times to make it. The cheaper fluids skip the extra steps.

But in all reality, if changing brake fluid every two years (like we are supposed to), the few extra bucks on a better fluid isn't really going to make much difference in overall maintenance costs per mile. Those tracking their cars will spend a lot more on fluid as they will replace it more often, but will also receive more benefit from the improved properties of the top shelf stuff (AP Racing PRF, Castrol SRF, Prospeed RS683, Motul RBF660 and a few others).

Chris

you should always compare the wet boiling point, not the dry since you should assume there is some type of moisture in the system or bottle already

Valvoline synthetic was discontinued over a year ago.

If you plan on keeping brake fluid in the vehicle for over two years, then, yes, wet boiling points should be compared. Brake fluid, if made and stored correctly before use, absorbs about 1.5-2.0% moisture per year while in the vehicle. Most of this moisture comes through the OE rubber brake lines -- another argument for upgrading to stainless steel braided Teflon hose. It is also an argument against pressurized brake bleeders that don't have diaphragms.

Since the SAE WERBP (Wet Equilibrium Reflux Boiling Point) test measures wet boiling points at 3.5-4.5% typical moisture content (the reference fluid is at 3.70% +/-.05%), we should only be concerned with the wet boiling point if we stay with OE rubber lines, use cheap pressure bleeders and aren't that concerned with regular maintenance. If, as enthusiasts, we choose to keep up on maintenance and use better lines and bleeding methods, the dry boiling point is much more relevant to our use.

Chris

they just changed the bottle. The white bottle with blue label is still synthetic
Its 480/311 which is fine for the street
http://www.valvoline.com/admin/p28.png

I'm all for quality stuff, but anything more is overkill on the street, assuming like AP Chris said, you are going to change your fluid every two years.

you should anyway

I just switched to a set of goodridge SS brake lines, & 4 bottles of Motul 600. The car is running great now.

So am I understanding that even though Nissan recommends DOT 3 that we should uses DOT 4 if we track?

yes

DOT4 and DOT3 are immiscible, so there is no problem using DOT4 on the track or on the street. It is a higher spec than DOT3 as it pertains to boiling points. Most racing fluid "conforms" to DOT4, although the best fluids are quite a bit better than the minimum specs call for.

Chris

If you guys are careful, you can bleed your brake system using a single quart of new fluid. Using the RBF600 and ATE SuperBlue alternating schedule, it's easy to know when you've adequately bled each caliper.

How often should you bleed the brakes if you run RBF600 on a mostly street driven Z?

Define mostly?

I bleed the brakes every 2 years on my street cars.

99% of the time just street driving, I would like to think someday I can go to a track for the first time haha. Thanks for the information, I am upgrading the fluid and pads for my base brakes since the stock pads and fluid cannot cope with any serious sustained braking, that's for sure.

If you are just driving on the street RBF600 is a waste of money. Given that it is recommended that you bleed the brakes directly before a track event, go with something a little more economical (but meets the DOT4 spec) until you hit the track.

For the Motul, I replaced mine on my other cars about every 6months. You should prob do it in smaller increments seeing as though it's a huge difference on the track everytime I flush the system.

Now I use Neo sythetic brake fluid, which lasts prob half as long, but I still replace every 6months. LOL.

I use AP Racing DOT 5.1. It is compatible with ABS, etc. Stillen sells it for about $14 a pint. Three pints are enough for flush and fill. The dry and wet boiling points are way higher than the stock DOT 3. I also changed the brake lines to Goodridge SS. That way the brake fluid will stay drier.

ss lines are to keep the brake pressures consistent, because the lines do not expand. It doesn't really have anything to do with brake fluid staying drier.

Pressure isn't lost with rubber lines, but fluid volume is. In other words, as I press the pedal and the rubber lines expand, more brake fluid must be provided by the master cylinder to keep filling the growing line volume. With SS lines, nearly zero growth means less pedal travel at the same pressure level as compared to OE lines.

OE rubber lines are the main pathway for moisture ingress in the brake system. This is why most manufacturers recommend changing brake fluid every two years. It's the moisture that lowers the boiling point and can eventually cause internal component corrosion. SS lines do not allow moisture through them, keeping the fluid "drier" -- or with a lower moisture content for a longer period of time.