Brake Fluid

[Guest]

Just because the fluid in the reservoir looks okay that doesn't mean the rest of the system fluid is.

I just finished overhauling the rear brake on my 84 Kat and found what appeared to be tan jello inside the master cylinder. Fortunately, the seals were all in good order (soft) so no need to replace them.

I'd never been inside a M/C before, and without a manual, I was a little nervous. However, I forged ahead and got the job done in a matter of an hour or so. Hugely satisfying!

If anyone has any trepidation I say fear not - these things are supremely simple.

[Nessism]

Yup, pretty easy work. Only hassle is when the rubber boots are old and torn.

BTW, when the brake fluid is solidified like you describe, a scale forms on the inside of the brake lines and they should be replaced. Failure to do this will contaminate your new clean brake fluid.

[Smokinapankake]

Agreed. I hosed them out with brake cleaner then flushed with high pressure water. Lotso goo came out but I'm still planning to upgrade to stainless lines in the near future.

[Shin-Ken 1074]

To help reduce problems with gunge and tan gello in the brake system I change the front and rear brake fluid twice each year. Brake fluid absorbs moisture and this causes most of the problems as the moisture/water contamination reacts with the brake fluid creating the various flavoured soups in our systems, still using J1703 in mine. Doesn't seem like much of a task but it has kept my master cylinders in good condition for many years. Cheers.

[Pete Logan]

Does anyone happen to know whether it's OK to use DOT 5.1 ?

All the literature says it's fully compatible with 3 and 4.

Thanks.

[crazedfooter]

small amount of brake fluid

congrats on the first mc rebuild. I am going to toss my question in here since it is related.

I just cleaned and rebuilt the calipers on my 1100, I used a bit of dot 4 fluid to lube everything when i put it back together. I have since decided to take the bike down to a bare frame and have it powder coated, which brings me to my question Will that brake fluid that i used in the calipers give me any problems (rusting, turning to goo etc) if it sits in them for an extended period of time (i figure six months worst case)

If i need to dismantle them and wipe the fluid out i will but i didn't want to if i didn't have to.

thanks for the input
nick

[Steve]

To help reduce problems with gunge and tan gello in the brake system I change the front and rear brake fluid twice each year.

Seems a bit of overkill, but if you don't mind the expense and trouble, that's great. I do mine every two years.
Another way to judge when to change fluid is color. The clearer the better. When it starts to look like root beer, a fluid change had better be high on your priority list. :shock:

Does anyone happen to know whether it's OK to use DOT 5.1 ? All the literature says it's fully compatible with 3 and 4.

Yes, 5.1 is OK. Just make sure the "point one" is there, as DOT 5 (no point one) is NOT compatible.

Will that brake fluid that i used in the calipers give me any problems (rusting, turning to goo etc) if it sits in them for an extended period of time (i figure six months worst case)

What shape is the fluid in right now? With the exception of Shin-Ken, most riders tend to change fluid every one or two years, so your six-month hibernation should not be a problem for reasonably fresh fluid. If in doubt, flush the system before you take the bike apart.


.

[Junkie]

You used WATER to clean out your brake lines? I hope you flushed a good full can of fluid through them after.


And yeah, 3 4 and 5.1 are all variations of the same thing. For some reason the really high performance fluids are all 4 though, not 5.1... no clue why. ATE Super Blue is nice.

[crazedfooter]

right now all thats in there is the little bit i used to push the pistons back in, the calipers are still sitting on a table, and the fluid was new as of two days ago.

i just wasn't sure since its not going to be in a sealed environment (as they will not be going back on the bike for a while)

nick