Brake Bleeding 101

[Jarhead767]

Can anyone send me some good info on bleeding brake fluid? I would like to change mine but want to do it right due to the importance of the brakes to work correctly after I am done

Help with fork oil changing would be nice too!

Thanks!!!

[ThAzKat]

Get a good vacuum pump and bleed it that way.

as far as disposing of the fluid, I can't answer or the EPA will be knocking at my door LOL

[The CyberPoet]

Brake fluid is just a very acidic (base?) hydraulic oil. Hence it can be recycled with standard motor oils -- recycle it in the same place you dispose of your motor oil (and I don't mean a dumpster or hole in the ground).

As for bleeding, here's what you need to know:

there are three ways of bleeding - standard (gravity/brake lever), plus forced top-down, and forced bottom-up. I will describe standard, because that's the way most people do it (unless the run into big problems).
on your bike are bleeder valves for the calipers. If you replace these with SpeedBleeders (available via any dealer with a PartsUnlimited account), life will be much easier. SpeedBleeders are bleeder valves with an one-way check-valve built-in (permits things to come out, but nothing to go back in).
doing the front left caliper? Put the bike on the sidestand. For the others (front right & rear), put bike on the centerstand or race stand.
Required Tools: 7 or 8mm wrench (can't remember which off the top of my head), fresh brake fluid (never use brake fluid which has been opened for more than a month or so), eye protection.
Suggested additional Tools: length of clear tubing that will fit over the bleeder nipple, plus an old spaghetti jar or mason jar. If used, place the tube over the nipple, put the far end of the tube in the mason jar and cover it with a bit of brake fluid. As you pump down, this will keep air from going back into the system.
Directions:
Put on the eye protection. Open the top of the brake fluid reservior. Fill with brake fluid. Have someone pump the brake, and then with the brake lever held down under force, open the bleeder valve at the bottom (caution: fluid may want to spray out if you're not using the tube method) and then close it again before all the pressure at the lever bleeds away. With the SpeedBleeders, the close procedure isn't necessary until you are done bleeding that side -- simply open 1/4 turn and pump your lever.
Repeat pump-bleed cycle. Whenever the reservior gets down to 50% full, refill it. Keep doing this until you get fresh fluid out of the bleeder valve. Then move to the other bleeder valve for those brakes and repeat the whole process. When finished, make sure the brake fluid is filled up to the full mark and close off the reservior again.
With the tube method, the air in the tube will bubble out first, and from that point on, only fluid should come out. If you see any bubbles comes out, keep bleeding, even if you are seeing fresh brake fluid (you still have bubbles in the system).

Remember, brake lines are rated for four years -- replace them at that point. The four year replacement schedule is based on both aging and wear from moving up/down/rotating as the wheels move -- you don't want to ever end up with unexpected brake failure.
Brake fluid darkens or turns murky as it absorbs water content (and all brake lines permit some water vapor transition); using a clear brake fluid, such as Castrol GT LMA or Valvoline PowerSynth will let you spot contamination early (and also help prevent dying the window of the reservior a color over time). Water content is the primary reason we change brake fluids.
Use only DOT 4 brake fluids in your Katana! DO NOT USE DOT 5.0 BRAKE FLUID -- it is not compatible.

Cheers
=-= The CyberPoet

[Teh_K]

Excellent write up CP, as usual - I was looking on how to do this too.

Do you know if this SpeedBleeder work for cars too?

[md86]

Speedbleeders are just replacement bleeder valves . You pop out the old bleeder bolt and replace it with the Speedbleeder . Takes about 1 minute to change the fluid and bleed the brakes wit hthose things in place . I LOVE mine . Got them from Speedwerks for about $12 a set (2 in a box , you'll need 2 boxes) .

[BraadaJim]

Speedbleeders are awesome!!!! Changed out my lines for stainless recently and had the whole system bled and tight inside of 10 minutes. Worth every penny and a few more!

[kiba]

Required Tools: 7 or 8mm wrench (can't remember which off the top of my head), fresh brake fluid (never use brake fluid which has been opened for more than a month or so), eye protection.

You will also need a philip screwdriver to get the top off the front reservoir. And that wrench is 8 mm.

/kiba

[Teh_K]

(2 in a box , you'll need 2 boxes) .

...and have 1 lonely bleeder left over? How sad...

Edit: Do KR members get any kind of discount? Sorry, I'm cheap...

[The CyberPoet]

Do you know if this SpeedBleeder work for cars too?

Yes, many auto parts stores carry speed bleeders for cars -- but know that they are usually a larger size than those used on the motorcycles.

KNOW THIS:
By this time next week I will be a SpeedBleeders (TM) authorized dealer.

2 in a box , you'll need 2 boxes.

98+:
one bleeder for each front caliper, two (one for each caliper half) in the rear. A lot of people miss the inside caliper bleeder when bleeding and when installing bleeders -- don't: this bleeder is actually more important that the outside bleeder in most cases.

Cheers
=-= The CyberPoet

[ShakaKatana]

hey CyberPoet...You have the speedbleeders yet???

are you going to sell them individually or per box??? How much??? Discount for KatRiders members???

[AkBigN]

When you put the speed bleeders on do you have to drain all the fluid in the lines, or can you switch them out real quick?

[kiba]

When you put the speed bleeders on do you have to drain all the fluid in the lines, or can you switch them out real quick?

I havn't done it, but my guess is that a little fluid will come out and you will need to bleed it afterwards to get that air out, but you shouldn't have to drain the whole thing.

/kiba

[Black_peter]

2 in a box , you'll need 2 boxes.

98+:
one bleeder for each front caliper, two (one for each caliper half) in the rear. A lot of people miss the inside caliper bleeder when bleeding and when installing bleeders -- don't: this bleeder is actually more important that the outside bleeder in most cases.

Cheers
=-= The CyberPoet

Pre 98 you will need 5
TWO for each front caliper.
ONE for the rear.

[The CyberPoet]

Not yet, but it's in the works. I'll even break them into specific set-sizes (5 for pre-98's, 4 for post-98's) so you can just order what you need as a complete solution.

Cheers
=-= The CyberPoet

[md86]

When you put the speed bleeders on do you have to drain all the fluid in the lines, or can you switch them out real quick?

I havn't done it, but my guess is that a little fluid will come out and you will need to bleed it afterwards to get that air out, but you shouldn't have to drain the whole thing.

/kiba

Yup , that's pretty much it . Just gotta watch getting the brake fluid all over the place (paint , rubber) .