Dot 3 or 4 brake fluid...

[fastpappy]

So definitely DOT4 but what flavor is preferred regular or synthetic??

 

[RossKean]

So definitely DOT4 but what flavor is preferred regular or synthetic??

Don't think it matters. I have used synthetic without problems.
I have never had an issue with brake fade but was wondering if anyone has tried DOT 5.1 hydraulic fluid? It has a significantly higher boiling point and is supposed to be compatible with DOT 4. (DOT 5 is a silicone fluid and is NOT compatible). Not planning on going there since I have never had a problem but I am curious. Higher numerical designation must be better, right?

(Its Friday!)

 

[ionbeam]

Why try 5.1? If you never had an issue with clean DOT 4 in an air free system on public roads there is no need for anything better. If you have had a failure on public roads I would suggest you are doing something wrong

Yes, the higher numerical designation means it is better for both dry and wet boiling points by a significant amount over DOT 4. The manufacturer's advertising tells the brainless masses that they should run to the store and buy the 'new and improved'.

The polyethylene glycol based 5.1 has very similar performance numbers to the silicon based 5.0 but retains the polyethylene glycol's compressibility ratings. Silicone based 5.0 has poor compressibility resulting in soft peddle and long brake lever/pedal travel with the only offsetting benefit of being non corrosive and paint safe.

 

[Donal]

The only 'benefit' I can think of is an improved additive package but I haven't seen any details posted anywhere. It would be nice to think you can buy improved protection for your ABS solenoids................... I change my hydraulic fluids out yearly for that very reason YMMV

 

[wfooshee]

I just wanted to repeat the notice that the reservoirs all have DOT4 molded clearly into the caps..... Not very confusing at all.

 

[ionbeam]

I just wanted to repeat the notice that the reservoirs all have DOT4 molded clearly into the caps..... Not very confusing at all.

The owners manual clearly spells out what grades of oil are acceptable....Not very confusing at all. But, we know how that turned out... :lol:

 

[DennisJ]

So definitely DOT4 but what flavor is preferred regular or synthetic??

I like Valvoline Syn-Power synthetic but don't think it has any particular advantage over any of the other major producers. Just been using it for years in my cars and now the FJR. Did notice that the local O'Reilly's did not carry it in their local stores (Bellevue, WA area) but I think NAPA may carry it. Need to bleed the FJR and car brakes this month so probably should look around this weekend unless we get a reasonably dry day in which case I will be out riding somewhere just to work out the bike a little and refresh my basic riding habits.

 

[fastpappy]

I was under the impression that synthetics were more resistant to absorbing moisture , would that make the maintenance intervals longer??