Brake Bleed, need help!!!!!!!!

[samm895]

I haven't found a thread that tell how to bleed brakes. What I was going to do is clean mc, then fill resevoir with new fluid, loosen two 8mm bleeder screws on front calipers, then gently pump brake lever till new fluid starts to come out at other end. Then top fluid off again. How far off am I????? --Never done this before.

[samm895]

Oh yeah i thought i should replace cap on mc before i started pumping on brake handle.

[Incubus]

Disassemble, clean and reassemble master cylinder and both calipers. Remount all three back on bike. Run bake line, but don't attach yet. Fill master cylinder reservoir. Pour brake fluid into each caliper through the hole the brake line attaches to. Attach brake lines to calipers. Pump brake lever with your finger over the hole where the brake line attaches to the master cylinder until you have resistance in the handle and brake fluid wants to squirt around your finger. Reattach brake line to master cylinder. Pump brake lever. Loosen one brake bleeder while keeping brake lever depressed to allow air to be forced out. Close brake bleeder, Repeat. A lot. After you bleed that one for a while and feel no improvement, switch to the other caliper and bleed it. While bleeding the second caliper you should start feeling resistance in the lever. Repeat, going from side to side, until all of the air is out of the brake line and the lever is firm.

Hint: Go to an auto parts store and pay $30 for a speed bleeder. It will save a lot of time and aggravation. Many folks have trouble getting their front brakes on their XS11s to bleed correctly. It is much quicker and easier with a speed bleeder.

Patrick

[fabricgator]

You can leave the cap off or loose.
When you pump the brake and release it may squirt up a bit and brake fluid is tough on painted parts, so clean it up as you go.

Use new DOT 3 brake fluid from a sealed container. Crack left brake bleeder first, then put a piece of vacuum hose on the bleeder screw and run it to a container to catch the old fluid.

Then I would slowly pump the handle to lower the level of the old fluid in the reservoir to just above any hole in the bottom of the reservoir. This way you have gotten most of the old fluid out 1st.

Then continue to fill and slowly pump the new fluid, thus flushing the master cylinder, hose to the splitter block and then the left hose and caliper. Continue until the fluid from the bleeder is "clear and bright" (clean).

Close that bleeder, and switch to the right hand caliper and fill and flush until the other is flowing clear and bright.

Note: if at anytime you let the fluid level get low to the point that the hole(s) in the bottom of the reservoir can suck air, then you must continue to fill and flush until all the air has been removed.

The vacuum hose in the container should stay below the old fluid level so that :
A) you can observe if any air bubbles come out...
B) will help ensure that air is not sucked back into the caliper when you slowly release the handle to take another charge of fluid into the master cylinder...

The rear brake is basically the same procedure.

When you are done, the brake should be nice and firm. This is indicitive that no air is in the system. An air bubble somewhere in the system will act like a spring and will compress when pressure is applied and expand when pressure is released. "Brakes feel spongy" You do not want air in hydraulic brake system.

[samm895]

Thanks this info should keep me out of trouble.

[fabricgator]

What Patrick said is all excellent information...

A complete disassembly, cleaning, inspection, replace any bad parts or complete rebuild kits are available. This is recommended if the brakes are neglected or not functioning.

The process I posted is for a maintenance flushing and replacement of the old brake fluid in a functioning system.

I reviewed what I posted and thought I would just make a few more comments.
"Crack the bleeder screw" There is no need to open a bleeder screw more then a half turn or so. If you don't get fluid flow from it, completely remove it and clean the two holes with a small wire, paperclip, brake cleaner or even WD 40 spray in a pinch. One hole is inside in the side of the bleeder screw and the other is on the outside where you connect the small hose to the scrap fluid catch cup.

I have not used the speed bleeders, I think they are a neat, great, invention that I should have thought up. The use of a length of vacuum hose (or that clear hose that you may have from a fish tank air compressor) submerged in the old fluid catch cup, works the same way, by not letting air suck back into the caliper.

When you pump the handle, do it slowly and gently..... both directions. Ease back off of it as it sucks the next clean charge of fluid from the reservoir. Wear safety glasses so you don't get a squirt in the eye. Keep an eye on the fluid level in the reservoir and make sure you keep fluid in there so the pump (master cylinder) does not get air in the system.

My procedure is done with the brake system installed on the bike and complete.

After any brake service or repair, DO NOT RIDE BIKE until you are certain the brakes are operating properly!

One more thing I do: after I am done... and sometimes before I ride as a preflight inspection. Squeeze the brake with everything you got. Try to break it...... if something is going to give, pop, leak, fail..... you want it to happen when you are at home AND when you life does not depend on it.

If you have any more questions..... just ask!

Kurt

[samm895]

possible clogged line?

So I bled out left side and went fine. When I went to do right, it acted like i never loosened the bleeder screw though I did. I went back to left and it still flows smoothly. Possible clogged line? I don't really know where to go from here other than take right side off at splitter but didn't know if all fluid will drain out if I do that. Going to start on rear till I here back. Thanks

[Incubus]

There are two conditions that could be causing the right side not to bleed. First, the brake line could be filled with solidified old brake fluid. If so, toss the line and replace it. You will NEVER get it clean enough to trust. Second, your brake bleeder screw could be clogged or the hole in the bottom of the bleeder hole could be plugged. See Fabrigator's post for the correct was to address that issue.

Patrick

[fabricgator]

If you don't get fluid flow from it, completely remove it and clean the two holes with a small wire, paperclip, brake cleaner or even WD 40 spray in a pinch. One hole is inside in the side of the bleeder screw and the other is on the outside where you connect the small hose to the scrap fluid catch cup.

Here is the section on the bleeder screw.

Kurt

[DGXSER]

A couple added things.

1. The issue with the bleed screw not flowing, I hope you did clean that caliper out, as in disassemble it and clean out everything including the groove the seal sits in.

2. After you get done bleeding, if you don't get a real firm feel. You can squeeze the brake handle about 3/4 the way in, and tie it there or use a bungee to hold it and leave it there overnight. In the morning you will find the lever much firmer.

[jmelin]

I use a homemade power bleeder.

Buy a new hand oil pump. You can not clean an old one good enough for your safety.

Attach a couple of feet of clear vinyl tubing to the spout. Fill the pump with clean brake fluid, then pump until all of the air is out of the line.

Do not fill the master cylinder prior to bleeding. You will fill it as you bleed.

Slip the free end of the line to your bleeder valve, remove the cap from the mc, loosen the valve, and pump.

I have used this setup for many years on various bikes and it works.

If you have multiple vehicles with different fluid types, use a seperate pump for each one. Do not mix DOT 3 and 5 in the same pump.

[xj11john]

I use a homemade power bleeder.

Buy a new hand oil pump. You can not clean an old one good enough for your safety.

Attach a couple of feet of clear vinyl tubing to the spout. Fill the pump with clean brake fluid, then pump until all of the air is out of the line.

Do not fill the master cylinder prior to bleeding. You will fill it as you bleed.

Slip the free end of the line to your bleeder valve, remove the cap from the mc, loosen the valve, and pump.

I have used this setup for many years on various bikes and it works.

If you have multiple vehicles with different fluid types, use a seperate pump for each one. Do not mix DOT 3 and 5 in the same pump.

The only thing I would do differently would be to bleed it first a few time the old fashioned way to get any crud that may be lurking inside the bleeder or caliper out, IMO just using the oil pump method right off the bat would push that crud up in the system and maybe back into the master cylinder.

Otherwise a very inovative way to an easy bleed.
Good luck, and ride safe.

[jmelin]

You are right I left out that you should disassemble, clean, inspect, and replace anything that looks the least bit bad on a system that could place your life in jeopardy. Then bleed.

[mjpxs11sh]

unable to bleed rears after caliper, line, and MC cleaning

i had no pressure at pedal to rear caliper after filling MC with new brake fliud.
dont laugh, well u can if u want, but this is what worked 4 me.
1) fill MC with new fluid and install MC diaphram, plate, and cover on with nuts
2) diconnect brake hose at caliper union bolt
3) fill caliper with fluid at brake hose entry hole
4) suck on the open brake line as u pump rear pedal until u taste fluid
5) re-attatch union with bolt to the caliper and tighten
6) bleed as normal until clear of bubbles and pedal pressurizes
7) let stand overnite and repeat after fluid settles if nec.

read many posts and thought id add this one. didnt have to bench bleed. all components were installed on bike and i was desperate not to pull it all apart again cause that rear MC is a B..ch!
get that beast back on the road already!

[mjpxs11sh]

road ready aft 15 yrs of storage

changed engine oil/filter, middle and final drive oil, front brake fluid, thorough rear MC, brake line and caliper cleaning, (rear caliper was smokin, front sticky), cam chain adjustment. aired up front suspension and tires, replaced 85mph speedo with 160mph set, installed cruise control and gave it a scrub. heres early pix b4 totally cleaned up. enjoy my hard work, hope it shows