Page 1 of 2
front brake bleeding problem
Posted: Fri Mar 04, 2011 2:21 am
by h zerbes
KLRista's,
I'd like to pick your brains on this one:
Situation:
95 model, 38000km.
Brakes were working fine (within KLR parameters, that is) but it was time to
change the front pads and fluid.
When I applied the lever to get pressure on the brake pistons and then opened
the bleeder valve at the caliper, no fluid was coming out, no matter how hard I
pressed the lever. I then took the valve out completely to check if it was
blocked (it looked good, is there a way to check it?).
By then, the fluid was coming out of the bleeder valve orifice and soon drained
the reservoir. I put the valve back in and refilled the reservoir but now cannot
get any pressure on lever, now matter how many times I pump (200+ so far).
Any ideas what might be wrong or how to proceed? I don't think the master
cylinder has a problem, as it was working fine so far.
What I noticed when the reservoir cap was off and I pumped, some fluid squirted
out of the reservoir (and onto the tank). Is that common?
Now that there is no pressure at all, nothing squirts anymore.
Cheers,
heinz
front brake bleeding problem
Posted: Fri Mar 04, 2011 4:25 am
by spike55_bmw
Almost seems like an O-ring / gasket has slipped in the master cylinder. Go back and open up the bleeder valve at the caliper and pump the brake lever?
If it still squirts out but you can't get any pressure at the brake lever when the bleeder is closed, then I'd say you have an air bubble.
If it doesn't squirt out at the caliper when you pump the brake lever, then I'd look at the reservoir's piston, O-rings, etc for the lack of a good seal.
Don R100, A6F
--- In
DSN_KLR650@yahoogroups.com, h zerbes wrote:
>
> KLRista's,
>
> I'd like to pick your brains on this one:
>
> Situation:
> 95 model, 38000km.
>
> Brakes were working fine (within KLR parameters, that is) but it was time to
> change the front pads and fluid.
>
> When I applied the lever to get pressure on the brake pistons and then opened
> the bleeder valve at the caliper, no fluid was coming out, no matter how hard I
> pressed the lever. I then took the valve out completely to check if it was
> blocked (it looked good, is there a way to check it?).
>
> By then, the fluid was coming out of the bleeder valve orifice and soon drained
> the reservoir. I put the valve back in and refilled the reservoir but now cannot
> get any pressure on lever, now matter how many times I pump (200+ so far).
>
> Any ideas what might be wrong or how to proceed? I don't think the master
> cylinder has a problem, as it was working fine so far.
>
> What I noticed when the reservoir cap was off and I pumped, some fluid squirted
> out of the reservoir (and onto the tank). Is that common?
> Now that there is no pressure at all, nothing squirts anymore.
>
> Cheers,
> heinz
>
front brake bleeding problem
Posted: Fri Mar 04, 2011 7:07 am
by Eric J Foster
Bike bleeding is a PITA! The service manual probably calls for a vacuum
type bleeder to suck the fluid through. You can also look for a "one man
brake bleeder" at most auto stores, it'll help, but is not a quick
answer. A good suck is always better.
If you let it sit there long enough with fluid in the reservoir, it
will at some point work it's way down through.
As you've figured out, once you crack the valve, never leave it unattended!
E
front brake bleeding problem
Posted: Fri Mar 04, 2011 9:18 am
by Michael Martin
Heinz,
It sounds like there is air in the master cylinder bore.
Here's a write-up I once did on the subject. The second half of it, bleeding
the system, should cover your situation.
http://home.insightbb.com/~mmartin36/Bleed.htm
As far as your question about the bleeder valve, this part is a simple part,
like a bolt with a hole drilled down its centerline. Then there is another hole
drilled from the side of it which intersects the first hole. If you poke a wire
down the first hole, you will be able to see the tip of the wire through the
side hole.
If this description doesn't match the part you have, then you may have a
Speedbleeder, which has a spring loaded ball in it to assist bleeding. Other
than forcing air or fluid through the part, I don't have a suggestion for
checking its operation. However, I do not think it's likely that this part is
your problem.
HTH,
Mike Martin,
Louisville, KY
[Non-text portions of this message have been removed]
front brake bleeding problem
Posted: Fri Mar 04, 2011 9:28 am
by Eddie
If fluid began coming out the bleeder hole once the bleeder was removed,
yes. The bleeder is likely clogged.
I've run a fine piece of wire (paper clip, safety wire, what have you)
through them and then flushed it with spray brake cleaner.
Before reinstalling it, take some plumber's teflon pipe tape (about a
dollar a roll at a hardware store) and wrap the threads a couple of turns
being extra careful not to block the hole(s) along the length of the
threaded portion. The tape will help keep air out during the bleeding
process.
That you got a small fountain of fluid out the top of the reservoir at
least once means the system is building and releasing pressure as it should.
See the tiny hole in the bottom of the cleaned master cylinder? That's the
relief hole. Some master cylinders such as Honda, Suzuki, etc... have a
small metal device that hovers over the hole to prevent the fluid from
streaming outside the reservoir. I've used a valve clearance feeler guage
resting over the hole to prevent this on bikes that don't have the device.
Any strip of metal will do. Got a soda or beer can handy? Cut a strip from
it and rest it over the hole. Remove when you're done.
You likely had a bunch of air introduced to the system when the fluid ran
out. Now, you have to remove it.
Air wants to rise in a fluid. Pumping the fluid downward to push the
bubbles out can work - if the bubbles are small enough. But, it sounds like
you have a a BIG bubble in the line. If you have access to a Mity-Vac hand
vacuum pump, you could connect it to the caliper bleeder, build up vaccum
and then crack open the bleeder slowly while adding fluid to the reservoir.
The vaccum pump can and will suck the system dry very quickly. So, a helper
refilling the res. could come in handy.
No pump? Try this. It's cheap and works. Go to an auto parts store and
obtain a mechanic's syringe.
It looks like a large plastic hypodermic without any needle. Connect a
small diameter hose to it - windshield washer or aquarium air line tubing
will work - and then attach the free end to the bleeder. Extract the
syringe plunger and while holding it upright, pour in some brake fluid and
tap out any bubbles trapped in the line.
Now for the tricky part.
Have a helper dry out the master cylinder with a paper towel and stand by
to mop out any potentially overflowing fluid.
Carefully replace the plunger on the syringe and slowly depress it while
opening the bleeder a turn - pushing fluid up through the brake line. The
bubbles will come with it. Keeping the res. from over flowing, push through
a couple of ounces of fluid until it comes up fairly bubble free. Lock down
the bleeder, remove the syringe/hose and see what kind of handle pressure
you have then. It should be in the good to great range. Enough to bleed
things the old fashioned way "pump, hold, bleeder release, tighten bleeder,
repeat."
Good luck and have fun!
=)
eddie
> [Original Message]
> From: h zerbes
> To: DSN_KLR650@yahoogroups.com>
> Date: 3/4/2011 3:21:08 AM
> Subject: [DSN_KLR650] front brake bleeding problem
>
> KLRista's,
>
> I'd like to pick your brains on this one:
>
> Situation:
> 95 model, 38000km.
>
> Brakes were working fine (within KLR parameters, that is) but it was time
to
> change the front pads and fluid.
>
> When I applied the lever to get pressure on the brake pistons and then
opened
> the bleeder valve at the caliper, no fluid was coming out, no matter how
hard I
> pressed the lever. I then took the valve out completely to check if it was
> blocked (it looked good, is there a way to check it?).
>
> By then, the fluid was coming out of the bleeder valve orifice and soon
drained
> the reservoir. I put the valve back in and refilled the reservoir but now
cannot
> get any pressure on lever, now matter how many times I pump (200+ so far).
>
> Any ideas what might be wrong or how to proceed? I don't think the master
> cylinder has a problem, as it was working fine so far.
>
> What I noticed when the reservoir cap was off and I pumped, some fluid
squirted
http://groups.yahoo.com/group/DSN_KLR650/app/peoplemap/view/map
> Group Apps:
http://groups.yahoo.com/group/DSN_KLR650/grouplets/subscriptionsYahoo!
Groups Links
>
>
>
front brake bleeding problem
Posted: Fri Mar 04, 2011 9:55 am
by mark ward
Teflon tape....As Eddies said, jus a couple pf wraps, some people think the more the better, NOT!
Too much and it will just cut and bunch up, pushing it aside. NOT good.
Unless you have a WORN loose fitting, then use as a temp fix.
two wraps should be great. Follow the trun of the threads, so it doesn't back off.
DUHHH??? some things we write like it's to a person of NO KNOWLEDGE, thats becuase we have no idea of each person knowledge, AND that many are reading and LEARNING...
..ALOT, years of wrenching, And I still learn new tricks everyday, some should have been BASICS yrs ago.
ENJOY
--- On Fri, 3/4/11, eddie wrote:
From: eddie
Subject: RE: [DSN_KLR650] front brake bleeding problem
To: "KLR650 list" DSN_KLR650@yahoogroups.com>
Date: Friday, March 4, 2011, 3:28 PM
If fluid began coming out the bleeder hole once the bleeder was removed,
yes. The bleeder is likely clogged.
I've run a fine piece of wire (paper clip, safety wire, what have you)
through them and then flushed it with spray brake cleaner.
Before reinstalling it, take some plumber's teflon pipe tape (about a
dollar a roll at a hardware store) and wrap the threads a couple of turns
being extra careful not to block the hole(s) along the length of the
threaded portion. The tape will help keep air out during the bleeding
process.
That you got a small fountain of fluid out the top of the reservoir at
least once means the system is building and releasing pressure as it should.
See the tiny hole in the bottom of the cleaned master cylinder? That's the
relief hole. Some master cylinders such as Honda, Suzuki, etc... have a
small metal device that hovers over the hole to prevent the fluid from
streaming outside the reservoir. I've used a valve clearance feeler guage
resting over the hole to prevent this on bikes that don't have the device.
Any strip of metal will do. Got a soda or beer can handy? Cut a strip from
it and rest it over the hole. Remove when you're done.
You likely had a bunch of air introduced to the system when the fluid ran
out. Now, you have to remove it.
Air wants to rise in a fluid. Pumping the fluid downward to push the
bubbles out can work - if the bubbles are small enough. But, it sounds like
you have a a BIG bubble in the line. If you have access to a Mity-Vac hand
vacuum pump, you could connect it to the caliper bleeder, build up vaccum
and then crack open the bleeder slowly while adding fluid to the reservoir.
The vaccum pump can and will suck the system dry very quickly. So, a helper
refilling the res. could come in handy.
No pump? Try this. It's cheap and works. Go to an auto parts store and
obtain a mechanic's syringe.
It looks like a large plastic hypodermic without any needle. Connect a
small diameter hose to it - windshield washer or aquarium air line tubing
will work - and then attach the free end to the bleeder. Extract the
syringe plunger and while holding it upright, pour in some brake fluid and
tap out any bubbles trapped in the line.
Now for the tricky part.
Have a helper dry out the master cylinder with a paper towel and stand by
to mop out any potentially overflowing fluid.
Carefully replace the plunger on the syringe and slowly depress it while
opening the bleeder a turn - pushing fluid up through the brake line. The
bubbles will come with it. Keeping the res. from over flowing, push through
a couple of ounces of fluid until it comes up fairly bubble free. Lock down
the bleeder, remove the syringe/hose and see what kind of handle pressure
you have then. It should be in the good to great range. Enough to bleed
things the old fashioned way "pump, hold, bleeder release, tighten bleeder,
repeat."
Good luck and have fun!
=)
eddie
> [Original Message]
> From: h zerbes
> To: DSN_KLR650@yahoogroups.com>
> Date: 3/4/2011 3:21:08 AM
> Subject: [DSN_KLR650] front brake bleeding problem
>
> KLRista's,
>
> I'd like to pick your brains on this one:
>
> Situation:
> 95 model, 38000km.
>
> Brakes were working fine (within KLR parameters, that is) but it was time
to
> change the front pads and fluid.
>
> When I applied the lever to get pressure on the brake pistons and then
opened
> the bleeder valve at the caliper, no fluid was coming out, no matter how
hard I
> pressed the lever. I then took the valve out completely to check if it was
> blocked (it looked good, is there a way to check it?).
>
> By then, the fluid was coming out of the bleeder valve orifice and soon
drained
> the reservoir. I put the valve back in and refilled the reservoir but now
cannot
> get any pressure on lever, now matter how many times I pump (200+ so far).
>
> Any ideas what might be wrong or how to proceed? I don't think the master
> cylinder has a problem, as it was working fine so far.
>
> What I noticed when the reservoir cap was off and I pumped, some fluid
squirted
> out of the reservoir (and onto the tank). Is that common?
> Now that there is no pressure at all, nothing squirts anymore.
>
> Cheers,
> heinz
>
>
>
>
>
> ------------------------------------
>
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>
>
>
[Non-text portions of this message have been removed]
front brake bleeding problem
Posted: Fri Mar 04, 2011 10:18 am
by Eddie
=)
As Mark says, I wrote not knowing Heinz' level of experience.
Brakes can be frustrating even for a seasoned mechanic.
Like I tell my trainees in a credit card processor computer room, any day you learn at least a little something is a good day.
What I don't know is a LOT. And I've been at it for nearly 22 years.
eddie
Snip from Mark's post.>>
Teflon tape....As Eddies said, jus a couple pf wraps, some people think the more the better, NOT!
Too much and it will just cut and bunch up, pushing it aside. NOT good.
Unless you have a WORN loose fitting, then use as a temp fix.
two wraps should be great. Follow the trun of the threads, so it doesn't back off.
DUHHH??? some things we write like it's to a person of NO KNOWLEDGE, thats becuase we have no idea of each person knowledge, AND that many are reading and LEARNING...
..ALOT, years of wrenching, And I still learn new tricks everyday, some should have been BASICS yrs ago.
ENJOY
[Non-text portions of this message have been removed]
front brake bleeding problem
Posted: Fri Mar 04, 2011 10:53 am
by Bill Ahrens
Putting Teflon tape on brake bleeder fittings does not accomplish anything;
the sealing is done between the pointy end of the brake bleeder and a
tapered seat in the brake housing. If the seat or bleeder is damaged, tape
will not help. The threads are not tapered like pipe thread.
Bill Ahrens
Race Chairman Emeritus
Tucson Sailing Club
_____
From:
DSN_KLR650@yahoogroups.com [mailto:
DSN_KLR650@yahoogroups.com] On
Behalf Of eddie
Sent: Friday, March 04, 2011 9:18 AM
To: KLR650 list
Subject: RE: [DSN_KLR650] front brake bleeding problem
=)
As Mark says, I wrote not knowing Heinz' level of experience.
Brakes can be frustrating even for a seasoned mechanic.
Like I tell my trainees in a credit card processor computer room, any day
you learn at least a little something is a good day.
What I don't know is a LOT. And I've been at it for nearly 22 years.
eddie
Snip from Mark's post.>>
Teflon tape....As Eddies said, jus a couple pf wraps, some people think the
more the better, NOT!
Too much and it will just cut and bunch up, pushing it aside. NOT good.
Unless you have a WORN loose fitting, then use as a temp fix.
two wraps should be great. Follow the trun of the threads, so it doesn't
back off.
DUHHH??? some things we write like it's to a person of NO KNOWLEDGE, thats
becuase we have no idea of each person knowledge, AND that many are reading
and LEARNING...
..ALOT, years of wrenching, And I still learn new tricks everyday, some
should have been BASICS yrs ago.
ENJOY
[Non-text portions of this message have been removed]
_____
size=1 width="100%" noshade color="#9d9da1" align=center>
No virus found in this message.
Checked by AVG -
www.avg.com
Version: 10.0.1204 / Virus Database: 1435/3481 - Release Date: 03/04/11
[Non-text portions of this message have been removed]
front brake bleeding problem
Posted: Fri Mar 04, 2011 12:05 pm
by Ian
I'm no expert and can't explain why you couldn't pump fluid out at first, but I have had the same frustrating experience with more than one bike getting the master cylinder pumped up after changing to braided lines or replacing fluid.
As near as I can figure out, it seems the master cylinder won't pump fluid without a little back pressure. In my frustration I disconnected the brake line and put my thumb on the master cylinder and it would begin to pump. I then reinstalled the line, pumped a few dozen times, and repeated until after maybe 400-500 pumps, and filling the reservoir five or six times, the line and caliper were full enough to provide the back pressure needed to actually bleed the system. I always use a small hose on the bleeder into a jar with two or three inches of fluid in it, to avoid sucking air back into the line.
Some guys have some special power bleeders or other tricks to pump fluid into the system, sometimes up from the bottom, to avoid this hassle. A large syringe or something.
--- In
DSN_KLR650@yahoogroups.com, h zerbes wrote:
>
> KLRista's,
>
> I'd like to pick your brains on this one:
>
> Situation:
> 95 model, 38000km.
>
> Brakes were working fine (within KLR parameters, that is) but it was time to
> change the front pads and fluid.
>
> When I applied the lever to get pressure on the brake pistons and then opened
> the bleeder valve at the caliper, no fluid was coming out, no matter how hard I
> pressed the lever. I then took the valve out completely to check if it was
> blocked (it looked good, is there a way to check it?).
>
> By then, the fluid was coming out of the bleeder valve orifice and soon drained
> the reservoir. I put the valve back in and refilled the reservoir but now cannot
> get any pressure on lever, now matter how many times I pump (200+ so far).
>
> Any ideas what might be wrong or how to proceed? I don't think the master
> cylinder has a problem, as it was working fine so far.
>
> What I noticed when the reservoir cap was off and I pumped, some fluid squirted
> out of the reservoir (and onto the tank). Is that common?
> Now that there is no pressure at all, nothing squirts anymore.
>
> Cheers,
> heinz
>
front brake bleeding problem
Posted: Fri Mar 04, 2011 12:48 pm
by Fred Hink
Was the rubber cap on your bleeder valve? It is there to keep dirt and
debris out of this valve. If that cap is missing, more than likely you have
it plugged and will need to be cleaned out before it will bleed out brake
fluid and or air from your caliper. I use a small drill bit by hand to
remove anything inside the bleeder valve. There are also two small holes
near the bottom that will need to be cleaned out too. Once you get the
bleeder valve clean, then your other problem is that you have allowed air
into your brake line. Since air wants to rise in your brake fluid and the
front brake line rises from the master cylinder, the air gets trapped there
and is hard to get bled out. If you are using the old standard,
pump-pump-pump-hold-bleed-pump-pump etc. procedure, it can be done but as
soon as you stop, you have lost all you have gained as the air rises back to
the high spot in the brake line. You need to keep at it without stopping or
go with a Mityvac or other type of vacuum procedure to get the air out of
your system.
Good luck.
Fred
www.arrowheadmotorsports.com
From:
DSN_KLR650@yahoogroups.com [mailto:
DSN_KLR650@yahoogroups.com] On
Behalf Of h zerbes
Sent: Friday, March 04, 2011 1:21 AM
To:
DSN_KLR650@yahoogroups.com
Subject: [DSN_KLR650] front brake bleeding problem
KLRista's,
I'd like to pick your brains on this one:
Situation:
95 model, 38000km.
Brakes were working fine (within KLR parameters, that is) but it was time to
change the front pads and fluid.
When I applied the lever to get pressure on the brake pistons and then
opened
the bleeder valve at the caliper, no fluid was coming out, no matter how
hard I
pressed the lever. I then took the valve out completely to check if it was
blocked (it looked good, is there a way to check it?).
By then, the fluid was coming out of the bleeder valve orifice and soon
drained
the reservoir. I put the valve back in and refilled the reservoir but now
cannot
get any pressure on lever, now matter how many times I pump (200+ so far).
Any ideas what might be wrong or how to proceed? I don't think the master
cylinder has a problem, as it was working fine so far.
What I noticed when the reservoir cap was off and I pumped, some fluid
squirted
out of the reservoir (and onto the tank). Is that common?
Now that there is no pressure at all, nothing squirts anymore.
Cheers,
heinz
[Non-text portions of this message have been removed]