Brake bleeding for dummies?

[nnamssorxela]

Hello all,

First of all I would like to say that I am fairly new here (joined a while back looking for a bike and finally found one not too long ago). I picked up a 1998 Yamaha WR400 (yeah yeah, I know it's just a dirtbike :D) to convert over to supermoto. Well ever since I put on the hydraulic brake switch (and attempted to bleed the brakes but failed miserably) I haven't really been able to ride the bike. The rear brake was bled no problem, but I have tried everything for the front brake: tapping the lines, hanging the caliper above the bike over night, bleeding it above my head on one foot with a glass slipper, I mean everything. The first time I did it I forgot to put something the size of the rotor in between the pads (the caliper was off the bike and hanging) resulting in my brakes slowly tightening until they locked up (not a fun test ride). I did it again and after the test ride, the brakes are rubbing enough that I can hear it and feel the resistance when pushing the bike.

It was mentioned that I might have let the brake fluid absorb water out of the air, and that water was expanding as it heated up. It was also mentioned that I might need a stainless steel line, instead of the plastic/rubber or whatever is on there.

I decided the only option was to completely drain the system and start from new. I drained it as best as I could, and began to fill it up and bleed it (bleeding from the master cylinder by cracking the banjo fitting a little). Obviously there is no pressure whatsoever in the brake. How do I restore this pressure to continue the bleeding process? Pump the brake until I can't take it anymore, sleep, then do it again? Or should I possibly purchase a vacuum bleeder and give that a shot?

A member on a different forum (I believe he is a member on here as well: MrDude) mentioned that I post up a thread on here, asking for advice, and also that if someone wants to help a young broke n00b out, that I live on James Island and could use a helping hand or a vacuum bleeder. :smilebig:

Thanks for any and all help,

-Alex

[Mike]

I'll look around and see if I can find my bleeder. You could try to get a hold of DK at Shadetree.

[mccutch2u]

there are a number of ways to do it

1 you can use a vacuum pump which would be the quickest

basically you would fill the master cylinder and hook one end of the vacuum hose to the bleeder screw and pump while keeping fluid in the cyilnder until no air bubbles are present

2. take a piece of hose and attach one end of the hose to the bleeder screw and the place the other end into a jar of brake fluid, then pump the brake until there are no more air bubbles present then tighten the bleeder screw and check for a tight lever you may need to bleed the master cylinder first by filling the reservior with brake fluid and pump it until it tightens and hole pressure on the brake lever while loosening the brake line to release the air and retighten repeat as necessary until fluid comes out making sure you never run the reservior too low

3.

[fasterthanyours]

3?

I did option number 2 on my R6, worked like a champ.

[nnamssorxela]

I've done option 2 probably 100 times and no luck. I was told to go stainless (though I don't know how this could possibly help), drain all the fluid, bench bleed the master, then bleed the rest of then system, probably by using method 2. Of course by then I'll probably have broken down and bought a vacuum bleeder.


(Also, how do I make it so that this site sends me an email every time I get a new post?)

Thanks,
-Alex

[fasterthanyours]

Wouldn't help from what I know, but would look cool. Probably make you go faster too LOL ;)

Give it a day or 2, there's enough motorcycle goofballs on here with extra tools that will help you out.

Go into advanced reply mode and select Instant email notification at the bottom.

It's also an available option when you create a new thread.

[Scootimus]

If I had the time I'd be more than happy to help. I know you said you have done it a 100 times but keep trying. I had the same problem with my mini bike and just as I was starting to give up on it, it started working.

[nnamssorxela]

Thanks guys! I'm going out tomorrow and I'll swing by and possibly pick up a vacuum bleeder. There's a $20 one at harbor freight that looks nicer than the mity vac.

[gemini]

vaccum pump works well, just eb sure you don't get fluid in the pump. turns them to junk.

a small variation to method 2 in case you have problems, open bleder, press the brakes, close bleeder, release brakes and repeat until satisfied.

[mccutch2u]

it sounds like you have a caliper issue.............. you may want to get a manual there is one online if you do a search i have a copy saved on my pc but it sounds like the caliper is sticking i would pull it off and apply the brakes until the piston is out and work it back and forth to see if it has any resistance if so you may want to overhaul it or replace it, when you pressed the brakewhile the caliper was off it may have gone too far and now is binding make sure it isn't cock eyed or anything

[nnamssorxela]

I'm gonna try a stainless line and power bleeder first. If the problem persists I'll cry for help then maybe work on the caliper. (maybe it's a sign that I need to upgrade :P)

[nnamssorxela]

Got the vacuum bleeder today. If my new brake line comes in before I leave again for school I'll let you guys know how things go. If not, I have to wait until spring break.

[nnamssorxela]

Hey guys, just letting you know that the brakes are working again. A member I met on a different forum (I think he's a member on here as well); Tony from North Charleston, helped me a great deal today. Turns out there was some sort of lock or bubble in the hydraulic brake switch banjo fitting thing. We took the system completely apart and re-bled it again. Works like a charm so far! Now I have to wait until the stainless line comes in so I can do it again :)

[fasterthanyours]

I figured you had a bubble somewhere in the system.

[nnamssorxela]

Yeah, I never would have guessed that it would be in the banjo fitting, especially after bleeding it at the banjo. The one thing that I don't get though, is why the brakes started "coming on" and stopping the bike, as I thought a bubble made them squishy and lose power? Oh well, the problem is solved, bow all I gotta do is wire the bugger. Thanks for the help guys!
-Alex

[fasterthanyours]

My R6 did the same thing for a while until I bleeded them at the calipers.

I'd be going along and letting off the throttle and it was slowing down way to fast lol