Break fluid won't go down!

[Guest]

After tearing apart the front end and taking apart the calipers after my accident I reassembled and reset everything. I would be back on the road here for the last couple weeks before it seems to be coming to a close for me but I cant get my break fluid to go down for my front breaks. I suspect it is clogged but I know others on this site will have much more insight and suggestions on how to fix it. Correct me if I am wrong, but there are two holes in which the fluid drains? If so only one seems to be clear, the other would be but there is a hard piece with a tiny hole blocking (or that is the way it is made, I am not sure). What are everyone's thoughts? Aside from the issue is there any thing special I should be doing when changing/punting in new fluid?


Thanks

[chuck hahn]

What bike? Most masters have a bigger hole the fluid flows in and is compressed by the rubber cups inside. Then there is a very very tiny return port. like bread tie small hole.

Are you using a mighty vac to bleed or the pump the lever and loosen the bleeder nipple method? If the later, try to ever so slightly wiggle the lever and youll see a bubble come out of the big hole. Keep doing this and it will release the air trapped inside the bore. Also use the search feature using words like priming the master cylinder etc etc.

Most auto parts places have tool rentals. Tell them you need the power bleeder.

[robertbarr]

try to ever so slightly wiggle the lever and youll see a bubble come out of the big hole. Keep doing this and it will release the air trapped inside the bore.

This approach always does it for me. Just move the brake lever about half an inch, if that, again and again. With luck, you'll see a few little air bubbles float up from the base of the MC reservoir. Be patient. It might take a while. The more tiny bubbles you get out of there, the closer you are to being done. Soon enough, it'll bleed normally and you can force all the air out of the bleeder valve.

[CUEagle17]

Chuck,

I have a 1978 GS750. I don't really know any methods, I am going to try robetbarr's method and see if that works. If not i may be off to use the power bleeder. also, I dont see any large holes on my master cylinder, only two small, and one looks like there is a super tiny hole in the already small hole!

[Gorminrider]

I find the "Barr" method is the one though lately I've been using a syringe (no needle in it) to goose it a bit...sucking with it seems to help in between some pumping. Then , now that the MC is "primed" it's as said, pumphandle slow while open the bleed at Caliper-close bleed and release brake handle etc. To save that stage "pumpopenclose release", there's a doodad for bleeding brakes if not refilling them...

http://www.thegsresources.com/_forum/showthread.php?226985-Speedbleeders

but I am stealing that idea and playing with a tire valve in the drain line for next time...preliminary test is aah ...hopeful .Likely save trouble for the last bubbles anyways.

[Gregory]

I don't know if this will apply to your situation, but I learned a trick on the forum here regarding when the brakes don't get firm enough.

Pull lever in and tie it in with a rubber band, wire or string...then just leave it overnight. The next day WALLA, bubbles and therefore softness disappear and good hard brakes. (I have used that method twice when I didn't want to break out the pneumatic bleeder, and it worked miraculously)

[robertbarr]

but I am stealing that idea and playing with a tire valve in the drain line for next time...preliminary test is aah ...hopeful .Likely save trouble for the last bubbles anyways.

I've done that, and it works great. I used an expended spray bottle, like you'd get Windex in, and it functions perfectly as a check valve. This'll let you bleed almost anything single-handed. Ghetto, but effective. I'd doubt it would help in this case, though, since we need to prime the MC to get the juices flowing in the first place.

[Gorminrider]

Hey good one,RB! Spray-bottle guts ! (Back to the shop and try that one...) Especially would have been useful for the Goldwing I was fixing "pinhole" fail on. Two-man job without something like this and it'll save the saying, "pump-release-pump-release..."

[Steve]

I usually prime the master cylinder by removing the brake hose(s), then covering the hole with my finger. Squeeze the lever gently, while allowing pressure past the finger. Clamp down with the finger before releasing the lever, then repeating as necessary. Two or three strokes will usually do the job. Re-install the hose(s), continue to bleed the hoses and calipers.

.

[Gorminrider]

THAT'S actually the best way to prime alright...( When I'm smart, that's a good way but mostly stupid-I compulsively bolt-it-all together and then deal with the consequences after. )

I'd add for the OP to Always cover the tank with something-I know it's rusty already but it's a good habit for when it's painted nice. Saves dents on other jobs too.

[Grimly]

From a bakery supplies or a farmers' market50cc plastic syringe (sans needle), and some aquarium air hose. Put one into the other, put the other over the nipple, crack the nipple off and pull the plunger. Brakes? Easy - five minutes does both sides.
I've been using this method for years, while others have been buying fancy vacuum bleeders for stupid money. It cost me a buck.

[Gorminrider]

I am going to try that too! Enema size! good point per getting at bakery and farm- syringes like this don't show up at my drugstore. My only issue is trying to keep the rubbers of syringes from jamming when they have been used a few times...any secret for this? maybe vaseline or something that won't dry up?
Have to include this idea


from http://cx500forum.com/forum/technica...tml#post323912
(especially @ steve who dissed my carb-synch tool )

[Grimly]

I haven't had any problem with the current syringe rubber jamming up, but an older one did a bit. That had seen a few years' use though and it eventually became too grungy to be much good. They vary, of course; designed to be limited use and throw-away on the farm, so that they work for this app is a bonus

[Who Dat?]

After reading all these wonderful replies and suggestions, I can't help but wonder if it might work better with brake fluid?

[Gorminrider]

Found one! (60cc syringe) Cost me $3. Farm supply/Pet place.... "farm" and "aquarium" were the clues I needed,Grimly! ...Useful for setting oil level in forks too!
....I think my longevity issue is the rubber on the plunger swells and then comes off the stem when pulled after lying around too long (note to self:dissassemble and clean in soap and water from now on! )