Synthetic brake fluid for w124

[ps2cho]

I know that MB states that the brake fluid should be flushed every year for my 87' 260E, but I know that was back in 87' and much the same as oil technology is far superior today, has brake fluid become any better in regards to "hygroscopic technology"? (if there is such a thing...)

I see autozone carries DOT4 Synthetic brake fluid for like $6.99/L.

Would it be worth going Synthetic over regular?

Thanks,

[compress ignite]

EDIT:
Please Ignore my incorrect ramblings.
SEE KESTAS's CORRECT reply Below!

THANKS!

[Kestas]

Not quite. ALL brake fluid is synthetic. It's just that some manufacturers make a big deal of it and put the word "synthetic" on the bottle.

I haven't heard of any technological improvements with respect to "hygroscopic technology". There are minor variances between manufacturers.

DOT 3, 4, and 5.1 are all glycol-based and compatible with each other. The numbers denote the boiling resistance of each DOT grade. I'm not sure about the difference in hygroscopic properties between the different grades. I've heard that the higher grades actually absorb more moisture than the lower grades.

DOT 5 is silicone-based, and is incompatible with the other DOT grades.

[daddi]

DOT 5.1 is by far the best fluid to get the air out of.

[ps2cho]

Originally Posted by daddi

DOT 5.1 is by far the best fluid to get the air out of.

Just to clarify -- DOT 5 is silicon and DOT 5.1 is NOT, correct? So I should use either DOT4 or DOT5.1 ?

[compress ignite]

"DOT 3, 4, and 5.1 are all glycol-based and compatible with each other. The numbers denote the boiling resistance of each DOT grade. I'm not sure about the difference in hygroscopic properties between the different grades. I've heard that the higher grades actually absorb more moisture than the lower grades."

[Wodnek]

I flush the brake fluid every 2 years on all of mine. I alternate between the ATE Blue and Amber.

With a motive power pressure bleeder it takes less than a half hour per car.

The pressure bleeder was about $100 with adapters for most every car.

I use a 30 inch clear tube slipped over the bleeders to divert the old fluid into a container.

[Chas H]

You should use the grade of fluid recommended by the owners manual. There is a difference between DOT 3 and DOT 4.

[mak]

DOT 4 has a higher boiling point than 3,any other difference ?
mak

[Chas H]

Originally Posted by mak

DOT 4 has a higher boiling point than 3,any other difference ?
mak

There could be an issue with rubber parts compatibilty.
While DOT4 in general does have a higher DRY boiling point than DOT3, it is more likely to absorb moisture. So DOT4, if left in place for more than 2 years, might have a lower boiling point than 2 year old DOT3.
Unless one is extremely hard (abusive) on brakes the boiling point is academic. Follow the makers recommendations for the grade of brake to use.

[pawoSD]

I flush with the "synthetic" DOT 4 valvoline stuff every couple of years....