Brake Fluid Viscosity Test: DOT 3 vs. DOT 4 vs. DOT 4 LV

Pentosin has started making a DOT 4 Low Viscosity brake fluid that helps with modern anti-lock brakes. In this video, I compare the low viscosity fluid with regular DOT 3 and DOT 4 fluid with some unexpected results.

[@rendeath]

Measuring viscosity in this manner is highly inaccurate. You're simultaneously introducing surface tension as a variable rather than solely testing viscosity. If you want to have a fair comparison you must use a viscometer to determine sheer rate and stress and then calculate your result in centipoise.

[@mjgoffice]

Thanks for the video! I was waiting for a colder comparison where the low viscosity should really shine, but thank you for putting out what you have.

[@wehtjns]

thanks for all your hard work and support of sharing information.

[@mygiguser]

You didn't test water in the second test

[@charleshines6155]

I am really watching this because I own a Volkswagen and it is one of those cars that they recommend using low viscosity brake fluid in. The VW spec for that is 501.14 and it is on the cans of fluid the dealer sells. I suspect that stuff is very likely to be rebranded Pentosin. Pentosin is a known supplier of many fluids for those cars and similar cars. Would it make much if any difference if I just used regular DOT 4 fluid instead? As you might already know, fluids for Volkswagens and similar vehicles are usually expensive. How does $24.80 for a liter if transmission fluid sound to you? Sure there may be more expensive ones but these are those fluids that the dealer will tell you that unless you use them, bad things may happen one day as a result. The fact is that there are fluids that can be used that are cheaper BUT read the forums to make sure that they are not causing problems with your car (or would cause problems). One reason they recommend DOT 4 LV for that car is that the ESP is supposed to work better with it. I read somewhere that the ABS pumps in those cars have smaller fluid passages. I have never seen any comparison and I would not mess with mine to see, they are expensive to replace.

[@wesbez6226]

Did you not do a heat test.

[@truth409]

Havoc versus curiosity means high cohesion it sticks to itself high vescosity

[@alfa1712]

1ST comment. Respect your dedication to sharing info and knowledge with others in the 986 world.

[@BurnersCars]

Thanks! Is your screen name a reference to the 1,712cc Alfa Romeo Boxer engine? If so... respect!

[@slybunda]

would there be a difference in brake pedal travel with standard dot 4 vs dot 4 LV?

[@charleshines6155]

I wonder that myself. Or would the brake response be any different? I would expect the low viscosity fluid to flow more easily which would give a better brake response. The only problem is that without two identical cars but one with the low viscosity fluid and the other with the regular DOT 4 both driven the same way (acceleration and braking both the same) as a part of a controlled test it might be hard to tell for sure other than looking for any difference in brake pedal feel and travel.

[@johnnguyen7700]

Depend how long the DOT 4 LV been open. but that should not matter. I don't think your can was open for that long. Normal flush is 2 years. I live in Texas. My customer live in Texas. I was thinking DOT 4 LV was better for my customer. After Watching your video. It show me. I should keep on Using Super DOT 4 or DOT 5.1. If we was up north. DOT 4 LV it is. Thank You

[@BurnersCars]

Yeah, the DOT 4 LV was open some months... probably less than a year. And I totally agree. I won't bother with LV unless I go somewhere that routinely experiences freezing weather. Glad I could help! Cheers!

[@doriangray2347]

I would imagine covalent bonding with water would change viscosity. You mentioned the 4 LV to have been opened for a while. the difference between wet and dry boil is rather huge, so maybe these fluids change drastically when exposed to air. Try 4LV brand new compared to the old bottle of 4LV? Be great to see it at 0 F temps and 120 F temps.

[@BurnersCars]

Brake fluid definitely absorbs water and changes properties. You have some good thoughts. I would like to follow this up with a test of old (wet) brake fluid vs. new (dry) fluid. I'll have to tackle this test, again, when I get the time!

[@doriangray2347]

I wonder also if you have a good scale. Or else test this in a desiccated sort of environment. is this stuff anhydrous when it comes in a can? I would imagine it would absorb a lot of water in a few minutes if it was and very hydroscopic

[@maurod2433]

molto interessante, a questo punto penso proprio che lv abbia piu lubrificazione per le pinze e pompa freno il che' e un vantaggio in piu..👍🏻👍🏻👍🏻👍🏻👍🏻👍🏻

[@Michael-uo4jj]

so basically it should benefit me -9 Celsius yesterday change my tires to winter with my winter brake fluid 😆

[@musicfashionstyle9269]

Can i use DOT 4 LV On my Acura Tsx 2009

[@LeParadisDuGeek]

yes dot 3, 4, 4vl and 5.1 are compatible but Dot 5 NO

[@truth409]

That test is backwards that's not low viscosity that's high viscosity

[@setoman1]

Water raises the viscosity...

[@jayguy173]

test popular store stuff valvoline bosch and prestone brake fluids

[@BurnersCars]

Great suggestion! I've been thinking of doing a followup video.