Brake fluid preference

[Guest Anonymous]

In a reply to a big brake related question a well respected poster mentioned NOT using a specific brake fluid:

Do not use that fluid (Valvoline Synthetic Brake Fluid). Use Castrol Dot 4 or ATE or some other good Dot 4 fluid. Drain, flush and refill. Probably take 2 liters.

http://www.bmw2002faq.com/component/option,com_forum/Itemid,50/page,posting/mode,quote/p,433125/

I am familiar with your 02 the products and on that fact alone place great value on your opinion. But what is wrong with Valvoline Syn brake fluid?

I have used this product in several cars, trucks, and motorbikes without any problems. So, please be specific as to why you do not recommend this product?

I do not disagree with use of Castrol, especially because I have found it to be a very good product and it seems to be the gold standard for brake fluids. But I am not aware that it is the only good product available. For example, I do not know who makes it, but I'm pretty sure I have also used Ford's Dot 4 product too.

Thank you.

P.S. I think it might be helpful if this board had a separate area for posters to offer their opinions regarding products we all use, share, or buy. Such opinions could be good bad indifferent excellent etc.

[BillWilliams]

but I believe the DOT 4 and DOT 5 are friendly to certain types of seals in the brake components.

I don't think our older type seals like DOT 5.

[Guest Anonymous]

I may be jumping to conclusions, but you may be confusing the product with silicone based (Dot 5) brake fluid.

Some of that product claims to be compatible with other types of fluid but conventional wisdom says flush flush and flush if you change to the silicone based product.

According to the product descriptions, the Syn brake fluid absorbs fluid just like the traditional paint loving Dot 3/4.

Perhaps you are suggesting that just like certain synthetic motor oils, and their alleged incompatibility with engine seals, Syn brake fluid has similar issues. This would be the first I have heard of this theory. Considering the few manufacturers of these specialized seals and the obvious safety implications, I would guess the word would really be out there.

For what its worth, I drive 30+ year old cars, listen to AM radio and some day plan to purchase a color television with remote control!

[Shad]

I'm not touching the Syn/Reg debate, but on all of our track cars we use the good old, tried and true, FoMoCo PM1, High Performance DOT 3 Brake Fluid/550 Degrees(12 fl. oz.) $4.99. It's more than enough for our setups on the 2002's and very economical. (Note: we flush our brake systems before each race event so it's fresh from the fall of the green flag.)

Good stuff, No complaints...

HTH.

-s

[john_a]

I'm not touching the Syn/Reg debate, but on all of our track cars we use the good old, tried and true, FoMoCo PM1, High Performance DOT 3 Brake Fluid/550 Degrees(12 fl. oz.) $4.99. It's more than enough for our setups on the 2002's and very economical. (Note: we flush our brake systems before each race event so it's fresh from the fall of the green flag.)

Good stuff, No complaints...

HTH.

-s

Yep, I use the Ford HD brake fluid for the race car. It was better when it came in a metal can, but I still will buy the new PM1 part number for cars that get frequent fluid flush.

For street cars I get Castrol LMA, because it is readily available and supposedly has Low Moisture Affinity.

[Guest Anonymous]

Since I am currently using the Syn brake fluid (have been for at least 6 months) are you advising me to leave it or change to another brand?

(Brakes work fine - hard pedal, easy to lock all four wheels) I would just prefer avoiding any surprises.

Thanks

[JohnN]

years. It has a higher dry and wet BP than Castrol LMA (although not as high as Ate' Blue/Gold). Its cheap and very easy to find, it is certainly going to remain my choice until someone comes up with a good reason for me to change.

Cheers!!!

John N

[c.d.iesel]

.....in my BMW cars and bikes -

The Only One to use :

and avoid 'super blue' fluid.

If you have to ask,

you won't getit.

[JohnN]

to back up your opinion. . . .

John N

[John_in_VA]

as far as I know.

I have been using the Valvoline Synthetic DOT 4 stuff in the tii, E28 & E30 without any surprises for 2-3 years, but I don't race. The local place didn't carry Castrol LMA anymore so I gave it a try.

[fazeShift]

I think c.d. might be talking about the tendancy of any blue brake fluid to mess with seals. Often, the blue dye in the fluid will weaken the seals, causing squeaks in hydraulic clutches, leaks in slave or master cylinders, etc... It's that dye that is to blame. If you really like ATE, I would personally recommend their TYP 200 because it's pretty much the same as Super Blue, but without the blue.

I use Motul RBF600 in the GTI and might give it a try in the 02 in the future, as well. It's DOT4 and I absolutely love it, thus far.

Some people like DOT5, but I avoid it because I read this:

:::::::::::::::::::::::::

DOT 5 fluid is not hygroscopic, so as moisture enters the system, it is not absorbed by the fluid, and results in beads of moisture moving through the brake line, collecting in the calipers . It is not uncommon to have caliper temperatures exceed 200 F, and at 212 F, this collected moisture will boil causing vapor lock and system failure. Additionally, DOT 5 fluid is highly compressible due to aeration and foaming under normal braking conditions, providing a spongy brake feel. DOT 5 fluid is best suited for show car applications where its anti-corrosion and paint friendly characteristics are important.

:::::::::::::::::::::::::

[JohnN]

Since you like Motul, here is what they say:

http://www.buybrakes.com/store/MOTUL-8070HCM

Long life 100% synthetic fluid for hydraulic actuated-brake and clutch systems

DOT 5.1 NON-SILICONE BASE

TYPE OF USE

All types of hydraulic actuated-brake and clutch systems

in accordance with DOT 5.1, DOT 4 and DOT 3 manufacturers’ recommendations.

Fluidity specially designed for anti-locking brake system (ABS).

PERFORMANCE

STANDARDS : FMVSS 116 DOT 5.1 NON SILICONE BASE & DOT 4 & DOT 3 SAE J 1703

Long life fluid:

The high wet boiling point (185°C / 365°F), superior to DOT 4 (155°C / 311°F mini) and DOT 3 (140°C / 284°F

mini) fluids enables to use this product longer. Indeed, DOT 3 / DOT 4 and DOT 5.1 brake fluids have the property to absorb humidity contained in the air, which reduces their boiling points and consequently security.

The wet boiling point is representative of the fluid after one year of use.

Specially designed to anti-locking brake systems (ABS):

The viscosity (820 centipoises at -40°C / -40°F) lower than DOT 4 (up to 1800 cp) and DOT 3 (up to 1500 cp) brake fluids, allows an easier fluid circulation in micro-valves of anti-locking systems.

Perfectly neutral with seals used in braking systems. Anti-corrosion.

RECOMMENDATIONS

Mixable with DOT 3, DOT 4 and DOT 5.1 NON SILICONE BASE products.

Do not mix with silicone (DOT 5 silicone base) or mineral base fluids (LHM).

Store brake fluid in its original container, tightly closed to prevent absorption of moisture.

Aggressive chemical product if contact with hands, paint or varnish.

If skin contact, rinse thoroughly with water.

I'm still waiting for CD to show some beef behind the BS

Regards,

John N

Drain interval : 12 to 24 months as per manufacturers’ recommendations.

[fazeShift]

Whoops! Learn something new everyday! I'll edit my post above to nuke the 5.1 reference. Thanks, John!

As for the RBF600, I like it because of its slightly better stats for track use... It is pricey, but I thought it was worth it.

From here: http://www.buybrakes.com/store/MOTUL-8069HC

DOT 4 100% synthetic fluid for hydraulic actuated-brake and clutch systems

Very high boiling point : 593°F / 312° C

TYPE OF USE

All types of hydraulic actuated-brake and clutch systems requiring a non-silicone synthetic fluid.

Specially designed to resist to high temperature of racing actuated-brake (steel or carbon) and clutch systems.

Exceeds DOT 5.1 and DOT 3 standards also, except for viscosity at - 40°C (-40°F).

PERFORMANCE

STANDARDS : FMVSS 116 DOT 4 / SAE J 1703

Extreme thermal resistance and stability:

The very high boiling point (312°C / 593°F), superior to conventional DOT 5.1 non silicone base / DOT 5 silicone

base fluids (260°C / 500°F mini) and DOT 4 (230°C / 446°F mini) enables an effective brake even under extreme

conditions.

Efficient when rainy:

The very high wet boiling point (216°C / 420°F) superior to conventional DOT 5.1 non-silicone base fluid (180°C / 356°F mini) and DOT 4 (155°C / 311°F mini) enables to keep an efficient brake system when rainy. Indeed, DOT 3, DOT 4 and DOT 5.1 brake fluids have the property to absorb humidity in the air, which reduces their boiling points and increases the risk to get the phenomena called “ vapour lock ”. The wet boiling point is measured by humidifying the product with about 3.5 % of water.

RECOMMENDATIONS

3 Bottles recommended for full system flush.

Avoid mixing with polyglycols based brake fluid with lower performances.

Do not mix with silicone (DOT 5 silicone base) or mineral base fluids (LHM).

By the way, here is a place to get it cheaper. Great customer service, too:

http://www.purems.com/products/product.php/II=775

[KFunk]

Funny that CD says to use only BMW brake fluid, and not ATE super blue; since ATE blue is actually the factory recommended brake fluid for my '74 2002. It's even printed on my brake reservoir cap: ATE blau, and says it in my repair manual.

Anyways, I love the ATE super blue and have been running it for a year or two. I've had a rock solid pedal since I last bled the brakes over a year ago. Its held up for multiple laps on HRP, well after many modern cars came in to cool down.

The stuff is so thick that it won't leak. I've taken off and re-connected brake lines without spilling a drop. My clutch master cylinder used to leak a 1/2 pint of DOT3 per week into the pedal box, until I switched to ATE super blue. It hasn't leaked any noticeable amount since then.

[boxy02]

Funny that CD says to use only BMW brake fluid, and not ATE super blue; since ATE blue is actually the factory recommended brake fluid for my '74 2002. It's even printed on my brake reservoir cap: ATE blau, and says it in my repair manual.

Anyways, I love the ATE super blue and have been running it for a year or two. I've had a rock solid pedal since I last bled the brakes over a year ago. Its held up for multiple laps on HRP, well after many modern cars came in to cool down.

The stuff is so thick that it won't leak. I've taken off and re-connected brake lines without spilling a drop. My clutch master cylinder used to leak a 1/2 pint of DOT3 per week into the pedal box, until I switched to ATE super blue. It hasn't leaked any noticeable amount since then.

I just put ATE SB in my 74 2002's system last weekend. I've only used ATE Super Blue in my 930 (street & track car) using the 993 TT calipers and an ATE 23mm MC with never any problems with seals. It's in my 914 with 930 calipers and a 23mm ATE MC, no problems. And since the Tii MC I just installed in my 2002 was made by ATE, I have a hard time believing that Super Blue would "eat" up their own products.

I guess I "just don't get it"....ha ha ha!