DOT 4+ Brake Fluid explained

[j_cd]

Everyone's favorite subject. I found this document.



Regular DOT 4 has a minimum Wet Boiling Point of 165 degrees celsius, while the DOT 4+ spec is 180 degrees.

I was told at the dealer parts counter that Volvo just buys brake fluid from whoever and re-brands it. That doesn't sound like they're importing the DOT 4+, made only by BASF in Europe.

The important thing is, you want a fluid that combines high minimum boiling point with low viscosity. The low viscosity is so your ABS/TRACS system works optimally.

The ATE SL6 specs very close to DOT 4+, but IPD says it's not for my vehicle. Maybe it has something to do with it's Class 6 rating. Check out Pentosin DOT 4 LV, made by CRP Industries. You can find it on Amazon, and O'Reilly stores can get it in 24 hours if it's not in stock.

CRP Pentosin DOT 4 LV spec sheet

www.pentosin.net/f_brakefluid.asp

BG Tech Tips - European DOT 4 Plus Brake Fluid

Many forum users report excellent results with regular DOT4 fluid. If you're driving in Arctic conditions however, the low viscosity is probably not a bad idea.

[tjts1]

I use DOT3 in the 850 and 960. Never had a problem with it.

[j_cd]

I'm not sure which year Volvo switched from DOT 3 to DOT 4(+). The '98 manual says DOT 4+. My guess is, the Volvo engineers liked that DOT4+ fluid, but it didn't really catch on, and our brakes are fine with regular DOT 4.

I went to O'Reilly and asked about the Pentosin DOT 4 LV. They can get it, but CRP specifies their Super DOT 4 for Volvo, so I'll probably go with that.

[tjts1]

I'm not sure which year Volvo switched from DOT 3 to DOT 4(+). The '98 manual says DOT 4+. My guess is, the Volvo engineers liked that DOT4+ fluid, but it didn't really catch on, and our brakes are fine with regular.

Both owners manuals in the 1994 960 and 1996 850 say DOT 4+.

[tjts1]

I'm not sure which year Volvo switched from DOT 3 to DOT 4(+). The '98 manual says DOT 4+. My guess is, the Volvo engineers liked that DOT4+ fluid, but it didn't really catch on, and our brakes are fine with regular.

Both owners manuals in the 1994 960 and 1996 850 say DOT 4+. The Prestone DOT 3 bottle I have in the garage claims 284f wet boiling point and 470f dry boiling point. While DOT 4 and 4+ fluids are clearly superior in this respect, I'm not sure its worth the extra effort and expense on our cars.

[yair]

As far as I know, Volvo used dot 4 way back, in the 240 in the 1970 and my 1987 740T used dot4.

[bmdubya1198]

Good info! I actually have a bottle of Volkswagen branded brake fluid, which is rebranded Pentosin DOT 4 LV. My cousin is able to get it from work. I'm planning on using it in my R after I flush the brake system.