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Newb brake question

Started by hopelessmechanic, May 04, 2006, 06:19:39 AM

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hopelessmechanic

May 04, 2006, 06:19:39 AM
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
im a hopeless trying to be mechanic on the weekends

3imo

#1
May 04, 2006, 06:30:37 AM Last Edit: May 04, 2006, 06:32:33 AM by 3imo
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:
Not the brightest crayon in the box, but I can still be seen from a distance.  ;P
QuoteOpinions abound. Where opinions abound, mouths, like tachometers, often hit redline. - STARWALT

Jarrett you ignorant my mama...

MarkusN

#2
May 04, 2006, 06:42:58 AM
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

scratch

#3
May 04, 2006, 07:30:40 AM
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
The motorcycle is no longer the hobby, the skill has become the hobby.

Power does not compare to skill.  What good is power without the skill to use it?

QuoteOriginally posted by Wintermute on BayAreaRidersForum.com
good judgement trumps good skills every time.

hopelessmechanic

#4
May 04, 2006, 08:28:25 AM
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?
im a hopeless trying to be mechanic on the weekends

MarkusN

#5
May 04, 2006, 08:34:03 AM
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.

hopelessmechanic

#6
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?
im a hopeless trying to be mechanic on the weekends

3imo

#8
May 04, 2006, 08:50:30 AM
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!!!




Not the brightest crayon in the box, but I can still be seen from a distance.  ;P
QuoteOpinions abound. Where opinions abound, mouths, like tachometers, often hit redline. - STARWALT

Jarrett you ignorant my mama...

scratch

#9
May 04, 2006, 08:54:46 AM
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.
The motorcycle is no longer the hobby, the skill has become the hobby.

Power does not compare to skill.  What good is power without the skill to use it?

QuoteOriginally posted by Wintermute on BayAreaRidersForum.com
good judgement trumps good skills every time.

3imo

#10
May 04, 2006, 09:01:41 AM
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.




Not the brightest crayon in the box, but I can still be seen from a distance.  ;P
QuoteOpinions abound. Where opinions abound, mouths, like tachometers, often hit redline. - STARWALT

Jarrett you ignorant my mama...

3imo

#11
May 04, 2006, 09:05:32 AM
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!!

Not the brightest crayon in the box, but I can still be seen from a distance.  ;P
QuoteOpinions abound. Where opinions abound, mouths, like tachometers, often hit redline. - STARWALT

Jarrett you ignorant my mama...

hopelessmechanic

#12
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!
im a hopeless trying to be mechanic on the weekends

3imo

#13
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.
Not the brightest crayon in the box, but I can still be seen from a distance.  ;P
QuoteOpinions abound. Where opinions abound, mouths, like tachometers, often hit redline. - STARWALT

Jarrett you ignorant my mama...

3imo

#14
May 04, 2006, 09:50:54 AM Last Edit: May 04, 2006, 09:51:57 AM by 3imo
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.
Not the brightest crayon in the box, but I can still be seen from a distance.  ;P
QuoteOpinions abound. Where opinions abound, mouths, like tachometers, often hit redline. - STARWALT

Jarrett you ignorant my mama...

ukchickenlover

#15
May 04, 2006, 10:05:45 AM
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.

3imo

#16
May 04, 2006, 10:17:06 AM Last Edit: May 04, 2006, 10:18:11 AM by 3imo
**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.
Not the brightest crayon in the box, but I can still be seen from a distance.  ;P
QuoteOpinions abound. Where opinions abound, mouths, like tachometers, often hit redline. - STARWALT

Jarrett you ignorant my mama...

LimaXray

#17
May 04, 2006, 10:23:26 AM Last Edit: May 04, 2006, 10:24:27 AM by LimaXray
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
'05 GS500 : RU-2970 Lunchbox : V&H Exhaust : 20/65/145 : 15T : LED Dash : Sonic Springs : Braided Front Brake Line : E conversion with Buell Dual Headlight : SW-Motech Engine Gaurds ...

hopelessmechanic

#18
May 04, 2006, 10:40:33 AM
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:
im a hopeless trying to be mechanic on the weekends

hopelessmechanic

#19
May 04, 2006, 10:45:24 AM
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.
im a hopeless trying to be mechanic on the weekends
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