DOT 4+ has a higher boiling point. Unless you are tracking your car, DOT 4 would be fine.

Or you can go all out and get DOT 5.1

 

DOT 4+ has a higher boiling point. Unless you are tracking your car, DOT 4 would be fine.

Or you can go all out and get DOT 5.1

That said, make sure you read the label. I haven't been to an auto parts store that carries Dot 5.1 fluid made for cars equipped with ABS.

 

Just get ATE TYP 200 or Super Blue and be done. Easily found online and even locally at tuning shops.

 

Brake Engineer Hat on - DOT3, DOT4, DOT4+ and DOT5.1 are all Glycol based. The differences are in viscosity and boiling point. Use the grade that your car calls for (Volvos are usually DOT4), with DOT4 and DOT4+ pretty much interchangeable. DOT5 is silicone based. Do NOT interchange glycol and silicone based fluids.

Thank being said, +1 for BumpinVolvo, for your Volvo get ATE TYP 200 or Super Blue.

Landru

 

+1 on this. Complete Accuracy.

And I haven't heard that anyone has ever started recommending DOT5 in ABS systems... anyone have anything specific on it? Last I knew, you didn't want to do that (issue with foaming from rapid pulsation, if I remember correctly from brake school 20 years ago)

DOT 5, being Silicone based, (and non hygroscopic) is used in collector cars that sit around a whole lot in temp controlled environments, and also in racing applications where the fluid will be changed on a fairly regular basis. All of the DOT3 and 4 (and I assume 5.1, because it's the glycol that does it) are hygroscopic, in other words, they will pull moisture out of the system and suspend it, keeping rust from forming on the inside walls of the brake system. And that is why it's important to not store brake fluid long term, and also important to change your brake fluid every few years (to get the water loaded fluid out). The more water in the fluid, the lower the boil point (and therefore, the brake fade out point).

 

Super Blue is great. And you can get it in a different color as well, which helps you see whether you've flushed your brake fluid completely next time you do it. Amazon carries it as do most speed shops.

I've used it on the 850's (including one with a Porsche brake kit), on the XCV90 (felt a nice difference over trips involving repeated, hard braking and on the R). Great stuff for the money.

 

DOT 5 is used in systems that cannot afford to absorb water and systems that see a much higher brake temp. A lot of old roadsters and classic car guys use it because it prevents any rusting. It also protects any painted parts if a brake leak should occur... which would total destroy the paint if they used something other than DOT 5. The entire system has to be rebuilt to use it... like the Master cylinder, Slave, lines, seals, ect. You cannot switch back after going with DOT 5 since its silicone base is there for life.

While some brake fluids are rated 5.1, these fluids see wet temps well below DOT 4 fluid wet temps... so, a Dot 4 can have a better brake response than a DOT 5.1 fluid as it starts into the last half of its life. This is something else to ponder when dumping money into fluids.

Another thing... The brake fluid also feeds down into the slave cylinder. So besides brake temps, it also helps manage the slave cylinder and clutch under hard driving conditions.

Some people stay away from Super Blue, because Super Blue stains the parts. If you were to use Super Blue under the factory warrantee, the dealer could quickly void the warranty on any brake items due to the fact it's very easy for them to tell that you are using a fluid beyond the factory specs. Because of this, some lean towards a high temp fluid that is gold in color. Others go between Super Blue and Motul because it's an easier way to see a fluid flush... seeing one color go and the new color appear.

I've used both Super Blue and Motul. I've been using Motul 600 and 660 since SS member Helmut Ranff recommended them to the R forum, but I feel both ATE and Motul are great. Both brands hold up very well on the track and around town. You notice the brakes stopping power more when you pull out the OEM brake lines and replace them with a SS braided line.

Choosing between 4 or 5.1 is determined on how you drive. I would pay attention to dry and wet temps, then weigh the options against cost and usage.

 

Just go to a local dealer.. Dot 4+ is like 16$ for a large can (more than enough for a flush and more)

 

FWIW ATE SL6 DOT4 is 10 a liter from motive products.