Hi I bought a GS500 in farely good condition for $300. I am working on the front brakes right now. The scenario is the front brake system was completely bone dry, so I took the caliper off and made sure that was function properly and changed the pads. The brake hose itself does not visually appears to be crack free. so I took the brake reservoir off and checked that. I put brake fluid in it and pumped it with my thumb over the hole and I can purge the reservoir and feel bake pressure. As soon as I put it on the bike though I can pump the brakes a million times and no fluid will leave the reservoir. The bleed screw is closed and I do not hear any air exscaping anywhere. Any suggestions on what I'm doing wrong or what mechanically is wrong? Thanks for all the help
open your bleed Screw!!!!!!
you must allow the air to escape. until brake fluid comes out the screw. Then continue pumping until you no longer have air bubbles coming out of the bleed screw.
then tighten your bleed screw, check for leaks and your on your way.
BTW - congrats on the bike and welcome to the site. :thumb:
I have also read the tip to fill the system from the bleed screw. (With a long, clear hose and a funnel as a makeshift reservoir.)
Advantage: You don't have to force the air down through the system
True. I have heard using a Miti-Vac helps get the air out, too. But, there's the old standby: http://gstwins.com/gsboard/index.php?topic=19126.0
Ok guys i'm sorry I suck so bad but I can't get pressure in this system. I know that I am able to get pressure because when I isolate the resevoir I can get pressure but as soon as I put it back on the bike I can't get pressure. I don't know what to do. I read the manual and I read Kerry's replacing brake fluid article and I still can't seem to get pressure. I know once I get pressure how to get air out but how do I get pressure in the system to begin with?
Aparently the empty system does not give you enugh resistance so that all the brake fluid that you pump in is sucked back up. Try filling the line and caliper first by gravity. (Attach some funnel doohickey to the end of the brake line and run in brake fluid. Or fill from the bottom, as I wrote above.)
Once the line is mostly full it should get easier.
Thank you for helping me through this process. I appreciate it very much. One question if I were to fill the brake line from the top how would I remove the metal tip were the ubolts slide into?
Mate good luck with your brakes, but if you have any problems with them see a professional!
Brakes are one area you want working 120% :thumb:
if the lines are full of air the pump will feel "Pressureless" because it will compress the air.
brake fluid is alot harder to compress. thats your "pressure".
you must open the bleeder and pump and pump and pump and pump.
If MarkusN is right then just place your finger over the bleeder and allow the air to escape as you pump.
IMO the "problem" is simply a dry system. It happens to me everytime I have completely emptied brakelines. bike or car.
it takes a lott of pumping to get it to work. The "pressure" will increase as the fluid begins to fill the lines.
BE SURE TO OPEN THE BLEEDER!!!
Quote from: hopelessmechanic on May 04, 2006, 08:39:37 AM
Thank you for helping me through this process. I appreciate it very much. One question if I were to fill the brake line from the top how would I remove the metal tip were the ubolts slide into?
The only suggestion I can think of is to wrap a plastic bag around that and tape it to the brake line, around the brake line, and use that as a funnel.
hopeless said in his first post that he left the bleeder closed and fluid was not going down.
he's looking for "pressure" in brakelines that are full of AIR. not going to happen. the fluid will not go down unless the bleeder is open.
Before you go taking the lines apart and filling them with funnel, try my suggestion.
I don't mind being wrong. Feel free to tell me so.
another thing.
if you go the route of removing the line and funneling fluid. you will leave an air pocket in the line just after you reconnect.
you will have to pump all of that fluid out to get that little bubble out.
or you will not know its there, thinking the brakes are bled, leaving air in your system.
It is not the correct way to do it!! period!!
I don't know what to do. I just used 3imo's method and I pumped for a solid 25 minutes tightening the bleeder holding down the lever opening the bleeder to let the air out, closing the bleeder and pumping some more. The brake fluid did not move from the line inside the brake resevoir. Wow this is a lot of work :flipoff: take that brake system!
do not close the bleeder at all when pumping.
IT MUST STAY OPEN !!!!
#1 - open bleeder
#2 - fluid in reservior
#3 - pump, pump , pump.
DO NOT CLOSE THE BLEEDER.....until fluid comes out.
this is a hydraulic system.. the pump does not build pressure like a bike pump.
brake fluid cannot be compressed as easily as air.
pumping it with the bleeder closed does absolutely nothing!! just squeezes the air and unsqueezes.
What are you using to bleed the brakes with, use a tube with a valve in it then air will not be sucked back in. Just keep pumping with the bleed valve open and brake fluid should come out.
If you keep trying and it does not work your brake master cylinder may be at fault. You can buy a rebuild kit for it and will need a pair of circlip pliers to remove the break master cylinder piston circlip.
**not to knock anyones suggestions**
an easy remedy to air returning into to calipers is to place the tube from the bleeder into a cup or bottle with fluid in it.
the heavy fluid will slightly counteract the (very slight) vacuum created by the back pressure of the brake pump.
this is a minor issue and don't worry about it. it is not your problem just yet.
keep it simple.
#1 - open bleeder
#2 - fluid in reservior
#3 - pump, pump , pump.
DO NOT CLOSE THE BLEEDER.....until fluid comes out.
Quote from: 3imo on May 04, 2006, 09:47:14 AM
do not close the bleeder at all when pumping.
IT MUST STAY OPEN !!!!
#1 - open bleeder
#2 - fluid in reservior
#3 - pump, pump , pump.
DO NOT CLOSE THE BLEEDER.....until fluid comes out.
wait are you sure? Wouldn't he have to open bleeder, squeeze brake, close bleeder, release brake, and repeat a few dozen times? Or is it different because it is totally drained. My memory is so crappy I can't remember if I've ever total drained the brake system when changing brake fluid on my car. Oh well.
Another option would be to get a hand pump brake bleeder that sucks the brake fluid out through the bleeder valve. These are very nice, especially for cars so you don't need to get your smoking hott, yet not too bright, neighbor who wants to 'get dirty working on your car' to help you pump the brake while you open and close the bleeder valve.
edit: I guess you answered my question
Alright just finished pumping for another 20 minutes with the bleeder screw open the whole time and I got nothin. The fluid didn't even go down a little. :dunno_white:
I double checked all the fittings and they're tight. I would like to point to the resevior but why can I give it pressure by putting my thumb over the resevior but not when its on the bike. that would be the only reason I'm antsy to go out and by a rebuild kit.
I put on the bottle and the tube and got a little fluid in the tube(couple drops). The fluid in the tube goes up when I squeeze the brake lever and bake down when I release the brake lever. There are no air bubbles or anything is suggesting that I would be bleeding the air out. No matter how many times I pump that bubble just goes up and down in the same place.
maybe 3imo is off his rocker :laugh: :laugh:
try opening the bleeder, squeezing the brake, closing the bleader, then releasing the brake. do that a whole bunch of times and see if that helps
I am sure. very sure.
when you were watching that bubble, did you notice that it DID NOT move more than an inch one way or the other?
you have to under stand the system. it is a hydraulic system.
in your case a COMPLETELY DRY hydraulic system. it is full of air bubbles. This problem that your having is the reason why no book will ever tell you to drain the system Then put in your fluids.
every book will say to "flush" the old fluid with new fluid on top. AND warn you about not letting the reservior to suck air.
this has happened to me everytime I have drained brakes completely. everytime.
keep pumping it will work and it will take time. you tested your reservior and confirmed the pump works.
If you can't let go of the idea that the air is being sucked in....then just get a long hose, place it over your bleeder fitting and suck on it. keep the pressure and pump.
Quote from: hopelessmechanic on May 04, 2006, 09:37:04 AM
I don't know what to do. I just used 3imo's method and I pumped for a solid 25 minutes tightening the bleeder holding down the lever opening the bleeder to let the air out, closing the bleeder and pumping some more. The brake fluid did not move from the line inside the brake resevoir. Wow this is a lot of work :flipoff: take that brake system!
Sure... go ahead and try it again. but wadda I know :dunno_white:
maybe it will work the 2nd time around. :icon_rolleyes: ( I am being sarcastic)
**how do I get back on my rocker? :icon_confused:
ok, I outta here for the day.
Good luck. :thumb:
and please don't rebuild your brakes. they are fine.
3imo, his problem is that the large amount of air in the system is so elastic that it does not build enough vacuum to open the check valve in the cylinder. Thus the fluid is just pumped back and forth.
HLM, first change your nick, it spells bad luck ;)
Seriously, look here (http://www.gs-500.de/phpBB2/viewtopic.php?t=13153). The text is in German, but the pictures give you an idea how you can fill the system from the bottom by gravity.
Quote from: 3imo on May 04, 2006, 11:05:19 AM
Quote from: hopelessmechanic on May 04, 2006, 09:37:04 AM
I don't know what to do. I just used 3imo's method and I pumped for a solid 25 minutes tightening the bleeder holding down the lever opening the bleeder to let the air out, closing the bleeder and pumping some more. The brake fluid did not move from the line inside the brake resevoir. Wow this is a lot of work :flipoff: take that brake system!
Sure... go ahead and try it again. but wadda I know :dunno_white:
maybe it will work the 2nd time around. :icon_rolleyes: ( I am being sarcastic)
**how do I get back on my rocker? :icon_confused:
oh I didn't see that one... maybe I'm off my rocker :laugh: :laugh:
But wait what he said sounds backwards... is he saying hes closing the bleeder, squeezing, then opening? shouldn't it be the other way around? ie opening, squeezing, closing, releasing?
I do see what you are saying 3imo and you're probably right. The more I think about it, I don't think I've ever totally drained a brake system before because I know you're not supposed to, so I wouldn't know.
and yeah if you can get the fluid to go up and down the hose, your master cylinder is fine.
edit: I would still say try a hand pump brake bleeder if all else fails, they sell them at Sears
Giving up for today I'm going to go buy that thing at sears and hope that takes care of the problem. I still got a lot of bike to fix so trust me you'll be hearing from me again. Everybody that has helped so far, thank you and hopefully I'll be able to pass on the information that I retain from this project like you guys are passing it to me. :cheers:
Quote from: MarkusN on May 04, 2006, 11:16:38 AM
3imo, his problem is that the large amount of air in the system is so elastic that it does not build enough vacuum to open the check valve in the cylinder. Thus the fluid is just pumped back and forth.
cool. then sucking on the line as you pump will work.
I've always just pumped away, it takes a long time but always worked.
ok... now I'm really gone.
[f
OK..... If I had my camera working I'd have pics.
Last night as I was steadily chopping away in my diabloical GS CHOP SHOP, I decided to completely drain the front brakes. and see for sure.
after completely draining the fluid... I poured brand new brake fluid in the reservior.
I sucked on the tube attached to the bleeder screw, as I was pumping the brake, and it worked. I had all new brake fluid in like ten minutes flat.
which IMO means MarkusN is correct. :cheers:
I went out and bought a 60cc sirenge and a tube attatched it to the bleeder screw and within 120cc's of air being sucked out they pumped like champs. Everything is working great but is it normal to have a little rubbing on the pads when they are new? Thank you everybody who helped me on this and their will be more to come. Again THANK YOU :thumb:
rubbing normal, actually always. it sounds rougher with new pads cause they havent worn to match the rotors.
for cars I just do a bit of hard braking for a day or two and the sqealin/rubbing sound goes away.
on my bikes I use brake pad silencer gel from advanced auto. no noise no prob.
glad it worked out for you :cheers:
what you need to do is disconnect the brake pipe from the caliper and put that end into the resivoir. pump the brake till all air outa pipe then reconnect to caliper but try not to lose to much fluid. then run a bit of tube into a coffee jar half filled wit fluid. make sure tube is submersed. open bleed nipple, pump lever till all air outa caliper then close nipple. you should now have a good brake. ive found this is the only method that works. it was the great joey dunlop that told me this method. hope this helps