[wheelspin]

While touring the local Pepboys in search of some conventional DOT 3/4 brake fliud I discovered that only synthetics were available on the shelf as offered by Prestone, Valvoline, and Gunk.

I experimitted w/ the vastly superior DOT 5 syn brake fliuds in the early 80s, but I experienced problems w/ sticking pistons caused by swollen cups, even after flushing the DOT 3 & 4 out of the systems and filling w/ fresh DOT 5. New rubber brake parts cured the problem, allowing me to use DOT 5 in a variety of motorcycles and cars.

These new products are not identified as DOT 5, but are listed as being fully compatible w/ DOT 3 & 4 (no mention of flushing being required), causing me concern about topping up/mixing with my existing master cylinder's capacities.

Anyone else notice this change?

Les

[Mr_GTO]

I haven't. I know in both of my old mans restorations of his mid year corvettes, where all the lines/calipers had been changed/new/replaced, he has used DOT 5 with great sucess.

If you need regular DOT 3/4, I would suggest Castrol or Ford fluid.

[wheelspin]

I toured Autozone, Kragen, and NAPA today in search of DOT 3, 4, or 3/4 brake fluid and only found one old dirty can of Castrol DOT 4. Could it be that the above described syn fluid is slated to replace conventional (petro based) brake fluid @ a 100% increase in price?

Les

[lust4speed]

I just went through the same thing looking for fluid for the Yukon. Everything was synthetic 3/4 or Silicone 5 except for the Wagner brand DOT-4. Strange thing about this old-fashion mix was everything was in Spanish first and then in English underneath.

[KO]

Castrol LMA works the best.

[b777d]

Worked at Wagner brake fluid plant in St Louis Mo for 15 years, we never blended a can of dot 4 brake fluid.

Just put our label on it.

They (Federal Mogul) shut the brake fluid plant down a few years back and I'm sure the only thing about it that is still Wagner is the label.

[amcmike]

ATE Type 200 (it's BMW OEM brake fluid) is DOT 4, has a higher wet & dry boiling point than Castrol LMA, and comes in a steel can. The last part is extremely important since moisture is the enemy, and a plastic bottle will absorb moisture before you even put it in your system.

[69lm69gp]

Originally Posted by amcmike

ATE Type 200 (it's BMW OEM brake fluid) is DOT 4, has a higher wet & dry boiling point than Castrol LMA, and comes in a steel can. The last part is extremely important since moisture is the enemy, and a plastic bottle will absorb moisture before you even put it in your system.

And yet the reservoir on the master cylinder is plastic.

[engineer]

sorry, plastic bottles do not absorb or allow moisture to penetrate.

[KO]

Originally Posted by amcmike

ATE Type 200 (it's BMW OEM brake fluid) is DOT 4, has a higher wet & dry boiling point than Castrol LMA, and comes in a steel can. The last part is extremely important since moisture is the enemy, and a plastic bottle will absorb moisture before you even put it in your system.

The DOT ratings are based on boiling points so if it has a higher boiling point why is it only DOT 4?

[amcmike]

Probably because it is not silicone-based.

Here's the values:
Castrol LMA DOT  3/4 Wet 446 Dry 311
ATE Super Blue Racing Wet 536 Dry 392
(ATE TYP 200 is same as Super Blue except red in color)

[b777d]

Originally Posted by engineer

sorry, plastic bottles do not absorb or allow moisture to penetrate.

You are correct sir; I have run hundreds of wet and dry boiling points on brake fluid.

[Cammer-6]

DOT 5 can not be used in ABS systems.
I loved LMA when it came out,then went to silicone in all my classics. The only way to do silicone right is replace every rubber piece in system and bleed with very slow low effort pumps on the pedal. Air entrapment is the reason most silicone systems get low pedal.
Ive never had any problems with silicone since day one. Ive been buying Valvoline synthetic to put in my daily drivers with ABS for about 2 yrs and so far zero problems.
Local Discount auto still has regular DOT 3 here and its only about $1 quart cheaper.
I did notice a $2 increase in the Valvoline since the last Qt I bought.

[aMaizedGoat]

I had my master cyl, rear cyl, and front calipers rebuilt by a local brake guru. He suggested staying away from synthetic brake fluid, but suggested the ATE Super Blue or 200. You can switch between the two when bleeding, when the color changes, youre done.

[Tom McQueen]

http://www.mpbrakes.com/uploads/prod...osin_large.jpg

Only brake fluid I have used in my performance cars for the last 10 years.

[quicksilver97ta]

I went looking for brake fluid to use as I needed to bleed my 68's partially restored brake system (new master and ss lines). FWIW there was plenty of Valuecraft and another brand Dot 3 at the local Autozone. I ended up buying Valvoline Dot 3/4 Synthetic. After bench bleeding the master I started to bleed the the brakes and noticed there was some sediment at the bottom of the new Valvoline bottle.