Techniques on replacing brake fluid

[Gsxxx600]

What are your techniques when it comes to flushing out the old fluid?

Id rather get some input from the more experienced, instead of just giving it awhile...after all, it does eat ur paint.

I heard of ppl using syringes to suck out the fluid in the master cylinder...
Im just looking for some input, or even a how to.

thanks

[Anonymous]

The easiest way for me has been with a vacuum pump (typically designed for cars). It's makes bleeding take less than 5 minutes...tops. Available for like $40.

[stevnmd]

It's super simple... I don't bother sucking the old fluid out of the reservior, though you can if you'd like.

Open the reservior cap, suck old fluid out if you'd like. If you do, make sure you refill it before pumping the lever!

Remove the bleeder cap. Attach a clear piece of hose to the bleed nipple and put the other end of the hose into an empty container. Get the appropriate size box end wrench handy. Apply some pressure to the lever while loosening the bleed screw SLIGHTLY. Squeeze the lever completely. Before releasing the lever, close the bleed screw. Release lever. Repeat until all new fluid is coming out the bleed screw. KEEP AN EYE ON THE RESERVIOR. Don't let it run out of fluid or you'll be pumping air into the lines and have to start the whole process over... You're going to repeat the process until not only all new fluid is coming out, but no air bubbles are in the fluid, too. It helps to have two people. One to work the lever and keep topping off the reservior, and one to open and close the bleed screw. Fill the reservior close to MAX once done.

[KitKat]

Attach a clear piece of hose to the nipple

you said nipple!!!!

[Black_peter]

I have easy access to syringes..
(No LEGALLY!!) so I chose to remove the old fluid.
Before you do either do this:
Get a wire tie or NEW tiny plastic brush and loosen the gunk in the corners and edges of the reservoir.
This is like silt, if you run fluid through the system untill it pumps out clean in a week this silt will disolve and the fluid will be cloudy.

I'll say this: If the fluid is really bad?
Maybe it's time for a seal change?
If so just unbolt the whole mess drain it into a bucket and cean/replace refill..

As Cyber says:
Seals and hoses should be replaced every 4 years..

[Gsxxx600]

thanks fellas,

perhaps ill take a pic of my brake fluid, and you can let me know if it looks dirty?

[md86]

Get some Speedbleeders , they ROCK ! I changed my brake fluid in like 5 minutes after I put the new bleeders in !

[The CyberPoet]

Get some Speedbleeders , they ROCK ! I changed my brake fluid in like 5 minutes after I put the new bleeders in !

I'm a firm believer in SpeedBleeders, which replace the bleed valves in the calipers with ones that have one-way valves in them (you can't suck air back in!). Once installed, turn them 1/4 turn from closed and pump from the handlebars. One time purchase, and they run between $8 and $15 a pair, with one pair needed for the front and one pair for the rear on a 98+ Kat (probably the same for the pre-98's).

Meanwhile, brake fluid should be clear (water clear) to really light amber (think miller high-life watered down a little). Dirty brake fluid is varying shades of brown and/or murky, which is what happens as it gets water build-up in it. Anything that is as dark as a Guiness or New Castle Brown Ale means it's time to disassemble the calipers and really clean it out totally, because that means water build-up at the low-end of the system is virtually gauranteed.

Good Luck!
=-= The CyberPoet

[md86]

. One time purchase, and they run between $8 and $15 a pair, with one pair needed for the front and one pair for the rear on a 98+ Kat (probably the same for the pre-98's).

One pair for each CALIPER , you mean Unless of course the 98+are different .... Each caliper has two bleeder valves , so you'll need 4 up front , and have to get another pair for the rear , since they come in pairs . Didn't do my rear though , so not sure what you'll need there.

[The CyberPoet]

. One time purchase, and they run between $8 and $15 a pair, with one pair needed for the front and one pair for the rear on a 98+ Kat (probably the same for the pre-98's).

One pair for each CALIPER , you mean Unless of course the 98+are different .... Each caliper has two bleeder valves , so you'll need 4 up front , and have to get another pair for the rear , since they come in pairs . Didn't do my rear though , so not sure what you'll need there.

The 98+ is different then -- a single bleeder per front caliper, because it's a single-sided system (2 caliper pistons push from the outside side of the wheel, other side slides on carrier pins to even up the pressure from the inside pad -- no caliper pistons on the inside side of the 98+ calipers).

Cheers
=-= The CyberPoet

[md86]

Huh , I'll be damned ! I thought I had you on that one !

[Gsxxx600]

It's super simple... I don't bother sucking the old fluid out of the reservior, though you can if you'd like.

Open the reservior cap, suck old fluid out if you'd like. If you do, make sure you refill it before pumping the lever!

Remove the bleeder cap. Attach a clear piece of hose to the bleed nipple and put the other end of the hose into an empty container. Get the appropriate size box end wrench handy. Apply some pressure to the lever while loosening the bleed screw SLIGHTLY. Squeeze the lever completely. Before releasing the lever, close the bleed screw. Release lever. Repeat until all new fluid is coming out the bleed screw. KEEP AN EYE ON THE RESERVIOR. Don't let it run out of fluid or you'll be pumping air into the lines and have to start the whole process over... You're going to repeat the process until not only all new fluid is coming out, but no air bubbles are in the fluid, too. It helps to have two people. One to work the lever and keep topping off the reservior, and one to open and close the bleed screw. Fill the reservior close to MAX once done.

This is for just one caliper correct?
Ill have to repeat for the other side?

[The CyberPoet]

This is for just one caliper correct?
Ill have to repeat for the other side?

This is once for each bleeder screw you have. If you use the speed bleeders you don't have to concern yourself about closing the bleeder while still squeezing.

Cheers
=-= The CyberPoet

[Black_peter]

The thing that keeps me from speed bleeders??
The fact that I have more worrries about leaking at the threads than getting air back in.

Just to back up md86:
Each front caliper has two bleeders.
That equals four for the front.
(four pistons and four seals too )

One for the rear (go figure)
Actually the inside bleeders make caliper removal a bit of a PIA IMO...

[The CyberPoet]

The thing that keeps me from speed bleeders??
The fact that I have more worrries about leaking at the threads than getting air back in.

You're no more likely to have an air leak at speed bleeder threads than at regular bleeder threads -- and the bleeders I used (Gaffer?) had an additional rubbery compound on the threads to address just this sort of issue.

Cheers
=-= The CyberPoet