brake fluid

rsporsche

rsporsche

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i know this has been talked about previously, but not a lot of importance put on the discussion. we know that ATE Blue isn't available in the USA anymore ... and that is what i used to use in my 2002s. there has been discussion about DOT 3 and DOT 4 ... and some aversion to using DOT 5 (silicone). prior to 2002, BMW calls for DOT 5.1 ... which is downwardly compatible with DOT 3 + 4. i know that newer cars use DOT 4.0 LV (low viscosity) / DOT 4+

so in looking into this a little deeper,
DOT 3 - is glycol ether based - wet boiling point is 284 degrees F and dry boiling point is 401 degrees F - its viscosity is 1500 mm2/s
DOT 4 - is glycol ether / borate ester based - wet boiling point of 311 degrees F and dry boiling point is 446 degrees F - its viscosity is 1800 mm2/s
DOT 4+ - is glycol ether / borate ester based - wet boiling point of 311 degrees F and dry boiling point is 446 degrees F - its viscosity is 750 mm2/s
DOT 5.1 - is glycol ether / borate ester based - wet boiling point of 356 degrees F and dry boiling point is 500 degrees F - its viscosity is 900 mm2/s

so here's a question, what happens when you use a LV fluid (DOT 4+ / 4 LV) in an older car? not sure i want to go there, but all of my brakes are new (the calipers are about to be rebuilt).

here are some of better brake fluids i have seen in the market
ATE 200 DOT 4 - BF1200 ($19.19 - $20.65 / 1L) - <racing? - also listed for vintage>
ATE SL DOT 4 - 81229407513 - $74.70 / 5L> - listed for vintage BMW
ATE Super DOT 5.1
ATE SL.6 DOT 4 - ($15.34 - $18.98 / 1L) - <low viscosity> - listed for vintage BMW

Motul DOT 5.1 - 100951 ($11.00 / 500ml) - <firmer pedal / more aggressive bite than OE>

LiquiMoly DOT 4 - 20152 ($11.90 / 500ml) <for newer cars?>
LiquiMoly DOT 4 - 20154 ($7.50 - $10 / 500ml) <for newer cars?>
LiquiMoly DOT 5.1 - 20158 ($6.09 / 500ml)

any experience with any of these? what do the pros use?
 
Just bled the brakes this evening for the first time with the new calipers, master/slave, brake lines, rotors, pads, etc. I used the BMW DOT 4 that had come with something that I’d ordered, hopefully that will work out ok. All newer system, so perhaps newer fluid…
I used a motive powerbleeder, works phenomenally well. I had a cheaper one which then broke, so it’s the usual pay more once and be done. No brake fluid enters the motive system so it’s not hard to keep it clean and functional. I got the “black” because I found it used on marketplace, not sure why it’s more expensive at baseline. The FORD screw-on cap works perfectly for our brake reservoir.
 
I just re-built the entire brake system on an e12. I'm running dot 4, which is what come up as the OEM specification when they ran it at the auto supply shop.
Also bought a pressure bleeder. Changed my life...
 
"ATE 200 DOT 4 - BF1200 ($19.19 - $20.65 / 1L) - <racing? - also listed for vintage>:
and a Motive Pressure Bleeder that I would loan to you if we lived closer
 
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