Changing brake fluid

[A.J.]

Happy riding season! The weather here in Illinois is finally ride worthy and I haven’t been off my bike in a week. When I’m asleep I’m thinking about it lol. Anyway, a good friend of mine and a fellow forumer here said “always change your break fluid every season”. So my question is what kind should I use and where can I get it? This will be my first time doing so. I’m somewhat handy with a wrench when it comes to these wonderful bikes but any tips or anything I need to know would be much appreciated. Happy to be back and see some familiar posters! Be safe happy riding in 2018!

[jkv45]

This section should have what you need - https://faq.ninja250.org/wiki/Brakes

[cbinker]

I put this in my 250:
https://www.walmart.com/ip/Prestone-...12-oz/35764362
I even saw another guy I race with putting it in his R3.

[DannoXYZ]

If you're changing it out yearly, pretty much any DOT-3 fluid will do.

[1994Ninja250F]

You definitely don’t need to change it every season, brake fluid doesn’t get subjected to same stresses and extreme temperatures like the engine oil does.

Water/moisture absorption is why brake fluid gets “dirty”, and why it changes color as it gets older. If it’s tan/Brown, dump it. If it’s clear, you’re definitely good for another year.

I change mine every 3 years. The manual officially calls for either 2 years or 4 years, can’t remember.

[A.J.]

Hey guys thanks for all the tips. I went to O’Reilly since I too my moms bike battery in for a charge anyway and bought Prestone Dot 4. That’s pretty much what wiki said. Since I just bought the bike last summer I’m not sure when the fluid has been changed last although it was regularly serviced the expensive route before I got her. I changed the oil last season but used Mobile 1 synthetic 4T racing oil and it’s amazing stuff. As recommended by @ramjett. So I’ll go ahead and change it this summer (brake fluid). Probably do it this weekend and inspect the breaks very throughly. Appreciate the responses as always you guys are great!

[cbinker]

you may want to double check, pretty sure the ninjette uses dot 3 brake fluid.

[Ram Jet]

Originally Posted by DannoXYZ

If you're changing it out yearly, pretty much any DOT-3 fluid will do.

Kawasaki recommends DOT 4 for pregens.

Bill

[DannoXYZ]

Originally Posted by Ram Jet

Kawasaki recommends DOT 4 for pregens.

Bill

Yeah, DOT-4 has more overhead and can absorb more water than DOT-3 before it reaches too-low a boiling point. Better for longer 2-yr change intervals.

[cbinker]

Also Dot-4 and Dot-3 do not mix.

[Lump]

Originally Posted by cbinker

Also Dot-4 and Dot-3 do not mix.

Dot 3, 4, and 5.1 are glycol ether based. They are compatible, but like motor oils, you should use the recommended or higher grade fluid. Dot 4 and 5.1 also have borate ester to handle higher temperatures. DOT 3, 4, and 5.1 fluids are found in most brake and clutch systems
It is important never to mistake DOT 5.1 (glycol-based) with DOT 5 which is silicone-based and should never be mixed with any other DOT fluid.

[jkv45]

Originally Posted by Lump

Dot 3, 4, and 5.1 are glycol ether based. They are compatible, but like motor oils, you should use the recommended or higher grade fluid. Dot 4 and 5.1 also have borate ester to handle higher temperatures. DOT 3, 4, and 5.1 fluids are found in most brake and clutch systems
It is important never to mistake DOT 5.1 (glycol-based) with DOT 5 which is silicone-based and should never be mixed with any other DOT fluid.

Who's the genius that thought of making DOT 5 and DOT 5.1 not compatible with each other? Ya couldn't have just made it DOT 6 instead of 5.1?

DOT 5.1 is fine to use for most applications but DOT 5 is not.

Duh.

[DannoXYZ]

It has to do with boiling-point ratings:

DOT-3 = dry boiling 401F / wet 284F glycol-based
DOT-4 = dry boiling 446F / wet 311F glycol/ester-based
DOT-5 = dry boiling 500F / wet 356F silicone-based
DOT-5.1 = dry boiling 500F / wet 356F glycol/ester-based

Back in the '80s, I used DOT-5 in my Supra and it worked great! Can last for 5-years or more due to not absorbing water*. I was flying down moutain-roads with my brake-rotors glowing red-hot and there was absolutely zero fade or pedal depression. Only issue is that it's not compatible with ABS and you have completely to clean brake system with alcohol before switching. Making it a pain as upgrade and mainly of benefit in systems that use it from the start. Such as military vehicles which are the primary users of DOT-5 today.

So, a more compatible DOT-5.1 glycol-based fluid was developed that was backwards-compatible AND provided higher boiling-point than DOT-3 or DOT-4.


* rumours of DOT-5 causing water-pooling are mis-diagnosed. The fluid doesn't absorb water at all, so where does water come from? In all cases where this occurred, it was due to users not completely clearing brake-system of prior glycol fluid and water by flushing with alcohol. The issue isn't the fluid, but how it was used.

[Ram Jet]

Originally Posted by cbinker

Also Dot-4 and Dot-3 do not mix.

Thanks, I didn't know that. Anyway, DOT4 is imprinted right on the front master cylinder cover on the pregen.

Bill

[DannoXYZ]

Originally Posted by cbinker

Also Dot-4 and Dot-3 do not mix.

Originally Posted by Ram Jet

Thanks, I didn't know that. Anyway, DOT4 is imprinted right on the front master cylinder cover on the pregen.

Bill

They actually do mix and function perfectly OK. Only difference is you end up with a BP in between the two; kinda a DOT-3.5 fluid. If adding DOT-3 to DOT-4 it will lower your BP in system. If adding DOT-4 to DOT-3, it'll raise BP in system.

I have, along with plenty of others have put DOT-3 in master-cylinder without any issues. Part of this has to do with being able to use whatever supplies are within easy reach of tracks in event raceflais rears its ugly head. Need to be able to run to local auto-parts stores for supplies.

[A.J.]

I went with dot 4. Why? Because Kawasaki and my bike said so.

[Ram Jet]

Originally Posted by A.J.

I went with dot 4. Why? Because Kawasaki and my bike said so.

Me too!

Bill