DOt3 vs dot4 are there problems using dot 4? (4 Viewers)

[slicky rick]

The series 200 specifies dot 3, some owners had bad experience using dot 4 pedal staying mid way etc... can someone elaborate? Is this true or a myth. Cap on my 2018 says dot3 or dot 4

 

[gaijin]

Manual for my 2013 says:
SAE J1703 or FMVSS No. 116 DOT 3

But I'd go with whatever is your manual - or on your brake fluid resevoir.

HTH

 

[TeCKis300]

Dot 4 is a higher performance fluid, with a higher boiling point.

So why shouldn't everyone use dot 4? It's a matter of maintenance.

All brake fluids are hygroscopic, meaning they will absorb moisture. Dot 4 can be more hygroscopic, and/or its performance degrades quicker relative to dot 3.

Vehicle using dot 4 will need more regular flushes. My Porsche Turbo utilizes dot 4, and requires annual flushes. Dot 3 vehicles generally specify 3-5 year intervals for flushes. (Anyone know what Toyota recommends for intervals for the LC?)

If you don't mind more regular flushes, you can use dot 4. You have to ask yourself, can you really utilize the higher boiling point? Is it worth the trade for more maintenance?

 

[bjowett]

Dot 4 will absorb moisture at a quicker rate, but the wet boiling point is still higher than Dot 3 WBP. Corrosion issues can occur, so as TeCKis300 writes, more frequent flushing of Dot 4 may be required. There are also viscosity differences , with 4 being a bit thicker than 3, so there is a possibility that may play into the recommendation. There are low viscosity Dot 4 fluids available.

 

[slicky rick]

Here is the cap...

 

[gaijin]

Here is the cap...View attachment 1912103

It sure would be nice if we could read what the cap has embossed on it...

 

[slicky rick]

Apologies bro. Best the iPad can do. if we magnify it says “dot 3 or dot 4 from a sealed container”.