Cannot Bleed Clutch Slave

[Nicholr]

Hi All,

 

I have just installed the MPH bar/back riser kit on my 2002 Le mans and for reasons I cannot fathom I now cannot bleed the clutch and get any lever presuure. Worked fine at project start this morning prior to my diddling. Two questions as the MPH kit instructions are 'light'. One: does it matter which way you install the supplied clutch line?

 

And two: I removed the bleed valve from the slave to purge the original line before replacing it. In the acitivity I noticed a small ball bearing on the floor below the bike that I guessed was a check ball from the bleeder orifice. As I don't have an exploded diagram of the slave I am wondering if somehting else is supposed to be in there and now isn't.

 

Any suggestions?

 

Nicholr

[badmotogoozer]

The ball in question goes into the slave, under the bleeder. The bleeder should have a flat internal profile, not tapered like the restof the brake bleeders. OR it could be the ball from the clutch microswitch... prolly the only 2 possibilities.

 

Nothing else would have fallen out. I am unfamiliar with the MPH kit... I would think that if there was a leak, you'd see fluid eventually, must be air trapped somewhere...

[Nicholr]

Thanks for the thoughts Ryan,

I put the ball back into the slave as I was pretty sure that was were it came from. I was just concerned that there mught have been a small spring in the slave holding the ball shut like most check valves. Very strange condition. I can remove the bleeder from the slave and when I work the clutch lever I can push brake fluid thru the system. At that point I am thinking I have pretty much purged the air thru the new line. I re-install the bleeder, tighten it and pump the cluthch lever to try and build pressure. It doesn't, so I pull the lever in, and try and bleed thru the bleeder (quarter turn to open with lever held in). I repeat this process like you would for bleeding a caliper and I get no purging and no pressure no matter how many times I repeat the process? Feeling fairly dumb here especially as with this kit you also replace the front brake lines which I did with no hiccups whatsoever. Must be a low pressure system moving in as I am seriously 'dumbed down' by this !

 

 

 

 

The ball in question goes into the slave, under the bleeder. The bleeder should have a flat internal profile, not tapered like the restof the brake bleeders. OR it could be the ball from the clutch microswitch... prolly the only 2 possibilities.

 

Nothing else would have fallen out. I am unfamiliar with the MPH kit... I would think that if there was a leak, you'd see fluid eventually, must be air trapped somewhere...

[guzzipete]

 

Did you try:

 

- Exert a pressure on the internal piston in order to expell

all the fluid (or air) contained in the cap.

 

??

 

Good luck with it.

[Dan M]

Any suggestions?

 

Nicholr

 

It is a difficult bleed as the line is long and the clutch master does not displace much. You end you just moving the air back and forth in the line. I use a Phoenix Injector to push fluid from the slave bleeder back up to the master. It works great. There are other less expensive syringe type pumps to do the same job.

 

http://www.brakebleeder.com/

 

Another option is a vacuum bleeder which draws fluid from the master down.

 

http://www.compacc.com/p.cfm/c/1111014/p/544

[Nicholr]

Hi Dan,

 

Great advice. I went to local jobber and bought a small suction type pump and bleed the system with zero difficulty. I guess you were right about the line length possibly holding a bubble. I appreciate the help to all. By the way the MPH bar backs are quite a clever solution to the low bar woes. Very adjustable and just waht the chiropractor ordered.

 

Many thanks and have a great riding year ......

[Dan M]

Hi Dan,

 

Great advice. I went to local jobber and bought a small suction type pump and bleed the system with zero difficulty. I guess you were right about the line length possibly holding a bubble. I appreciate the help to all. By the way the MPH bar backs are quite a clever solution to the low bar woes. Very adjustable and just waht the chiropractor ordered.

Many thanks and have a great riding year ......

 

 

Very true. I have them on my '02 as well. IMO the Motobits foot controls are the the perfect paring to the MPH risers. They move your feet down and forward about the same amount the MPH risers move your hands up and back. Places old guys (like me) in a better, yet still sporting position.

[orangeokie]

. . . Any suggestions?

 

Nicholr

 

CLICKY PIC . . .

 

These little numbers keep the fluid moving in one direction so you don't end up just pumping it back and forth.

 

Besides the speed bleeder nipples, they have some other nifty stuff to help with the job. Nice folks too.

[twhitaker]

That's what I have on mine. Speedbleeders are great. SB8125L for the calipers and SB1010S for the clutch. I think the ball is still in my clutch bleeder beneath the SB1010S. Their bleeder bag works great too.

[80CX100]

On 5/24/2009 at 6:43 AM, guzzipete said:

 

Did you try:

 

- Exert a pressure on the internal piston in order to expell

all the fluid (or air) contained in the cap.

 

??

 

Good luck with it.

     I have the same issue that the OP did in this thread, but I "think" my problem is more complicated than just air in the new clutch line.

     I just put an MPH riser kit on my "new to me" 2002 Lemans 7K kms (not ridden much in it's life, it's mint, been garaged for last 3-4yrs and was working perfectly).

     The clutch line bled out fine; I noticed if the bleeding nipple was only opened 1/4 turn, it didn't let that much air out, sometimes none, 1/2-3/4 turn of the nipple let out much more air.

      I now have good fluid moving out the bleeder hole with no sign of air bubbles, but I have what feels like zero resistance on the clutch lever.

      I've read through numerous posts and in that information was a comment from Phil that the fuller motion of the m/c piston when bleeding can damage seals or get hung up on debris in the travel path it normally doesn't hit.

      I noticed when bleeding the clutch, that the rubber boot (covering the end of the piston where the lever exerts pressure on the m/c) made a funny squishy empty hollow sound that I never noticed before, like it was just the empty boot collapsing with no resistance from the m/c piston hidden inside it.

      The clutch lever has very little resistance when pulled but seems to spring back normally fwiw. 

      My theory at this point is that the end of the piston has stuck inside m/c, the fluid appeared relatively clean and not skanky, but the bike has sat for a long time and the piston may have got hung up on debris.

       I'll confirm later today, but I think the fluid I'm seeing coming out the bleeder nipple down at the slave cylinder is now moving because of gravity; not pressure from the m/c piston.

       I recently picked up a fair quality 1.5 l fluid syringe for draining the fluid on a sealed hydrostatic transmission on my lawnmower; I'm going to attempt to reverse engineer it down at the nipple on the slave cylinder and force fluid into the slave cylinder- line- m/c- piston; and hopefully push the piston back into proper position.

       For those in the know of how these systems work,,, am I off base or is there a better way of diagnosing and addressing the issue?

       If I do the reverse pressure attempt, how should I best set it up for success;

       Bleed nipple at the slave cylinder 1/4? 1/2? 3/4? turn open?

       Cover on reservoir at m/c on or off?

       Lever left alone or pulled in 1/2 way or to the bar?

       On this post that I replied to, the manual describes removing the slave cylinder and pushing the slave cylinder piston back, with my tranny crossover it sounds like a night mare job, but is that something I should consider doing if all else fails?

       Tia

        Kelly    

[Tinknocker]

A KTM trick is to zip tie the lever to bar overnight. Turn bars so reservoir is highest. It has worked for me, on my KTM anyway. Even after rebuilding  brake M/C and bleeding, it still had spongy lever. Did this trick, and next day had full operation. 

[gstallons]

On 7/4/2020 at 10:41 AM, 80CX100 said:

     I have the same issue that the OP did in this thread, but I "think" my problem is more complicated than just air in the new clutch line.

     I just put an MPH riser kit on my "new to me" 2002 Lemans 7K kms (not ridden much in it's life, it's mint, been garaged for last 3-4yrs and was working perfectly).

     The clutch line bled out fine; I noticed if the bleeding nipple was only opened 1/4 turn, it didn't let that much air out, sometimes none, 1/2-3/4 turn of the nipple let out much more air.

      I now have good fluid moving out the bleeder hole with no sign of air bubbles, but I have what feels like zero resistance on the clutch lever.

      I've read through numerous posts and in that information was a comment from Phil that the fuller motion of the m/c piston when bleeding can damage seals or get hung up on debris in the travel path it normally doesn't hit.

      I noticed when bleeding the clutch, that the rubber boot (covering the end of the piston where the lever exerts pressure on the m/c) made a funny squishy empty hollow sound that I never noticed before, like it was just the empty boot collapsing with no resistance from the m/c piston hidden inside it.

      The clutch lever has very little resistance when pulled but seems to spring back normally fwiw. 

      My theory at this point is that the end of the piston has stuck inside m/c, the fluid appeared relatively clean and not skanky, but the bike has sat for a long time and the piston may have got hung up on debris.

       I'll confirm later today, but I think the fluid I'm seeing coming out the bleeder nipple down at the slave cylinder is now moving because of gravity; not pressure from the m/c piston.

       I recently picked up a fair quality 1.5 l fluid syringe for draining the fluid on a sealed hydrostatic transmission on my lawnmower; I'm going to attempt to reverse engineer it down at the nipple on the slave cylinder and force fluid into the slave cylinder- line- m/c- piston; and hopefully push the piston back into proper position.

       For those in the know of how these systems work,,, am I off base or is there a better way of diagnosing and addressing the issue?

       If I do the reverse pressure attempt, how should I best set it up for success;

       Bleed nipple at the slave cylinder 1/4? 1/2? 3/4? turn open?

       Cover on reservoir at m/c on or off?

       Lever left alone or pulled in 1/2 way or to the bar?

       On this post that I replied to, the manual describes removing the slave cylinder and pushing the slave cylinder piston back, with my tranny crossover it sounds like a night mare job, but is that something I should consider doing if all else fails?

       Tia

        Kelly    

Kelly , whatever you do , you keep this device dedicated to brake fluid ONLY . No mixing brake fluid with any petroleum products . 

 Good luck . When Ford first started using hydraulic clutches on trucks , there was NO procedure that worked 100 % of the time . 

[Lucky Phil]

On 7/5/2020 at 1:41 AM, 80CX100 said:

     I have the same issue that the OP did in this thread, but I "think" my problem is more complicated than just air in the new clutch line.

     I just put an MPH riser kit on my "new to me" 2002 Lemans 7K kms (not ridden much in it's life, it's mint, been garaged for last 3-4yrs and was working perfectly).

     The clutch line bled out fine; I noticed if the bleeding nipple was only opened 1/4 turn, it didn't let that much air out, sometimes none, 1/2-3/4 turn of the nipple let out much more air.

      I now have good fluid moving out the bleeder hole with no sign of air bubbles, but I have what feels like zero resistance on the clutch lever.

      I've read through numerous posts and in that information was a comment from Phil that the fuller motion of the m/c piston when bleeding can damage seals or get hung up on debris in the travel path it normally doesn't hit.

      I noticed when bleeding the clutch, that the rubber boot (covering the end of the piston where the lever exerts pressure on the m/c) made a funny squishy empty hollow sound that I never noticed before, like it was just the empty boot collapsing with no resistance from the m/c piston hidden inside it.

      The clutch lever has very little resistance when pulled but seems to spring back normally fwiw. 

      My theory at this point is that the end of the piston has stuck inside m/c, the fluid appeared relatively clean and not skanky, but the bike has sat for a long time and the piston may have got hung up on debris.

       I'll confirm later today, but I think the fluid I'm seeing coming out the bleeder nipple down at the slave cylinder is now moving because of gravity; not pressure from the m/c piston.

       I recently picked up a fair quality 1.5 l fluid syringe for draining the fluid on a sealed hydrostatic transmission on my lawnmower; I'm going to attempt to reverse engineer it down at the nipple on the slave cylinder and force fluid into the slave cylinder- line- m/c- piston; and hopefully push the piston back into proper position.

       For those in the know of how these systems work,,, am I off base or is there a better way of diagnosing and addressing the issue?

       If I do the reverse pressure attempt, how should I best set it up for success;

       Bleed nipple at the slave cylinder 1/4? 1/2? 3/4? turn open?

       Cover on reservoir at m/c on or off?

       Lever left alone or pulled in 1/2 way or to the bar?

       On this post that I replied to, the manual describes removing the slave cylinder and pushing the slave cylinder piston back, with my tranny crossover it sounds like a night mare job, but is that something I should consider doing if all else fails?

       Tia

        Kelly    

There could well be a lot of air trapped at the top hose connection to the master cylinder. Unbolt the master and carefully with the cap off tilt it so the reservoir is higher than the banjo connection and jiggle the lever. By jiggle the lever I mean just that, dont attempt to actuate the lever just jiggle it in it's play region. You will see air bubbles come into the reservoir. You can also while you have it in this position tap the accessible clutch line with the handle of a screwdriver to break free any air bubbles. They will come into the reservoir once again.

Ciao

[80CX100]

1 hour ago, Tinknocker said:

A KTM trick is to zip tie the lever to bar overnight. Turn bars so reservoir is highest. It has worked for me, on my KTM anyway. Even after rebuilding  brake M/C and bleeding, it still had spongy lever. Did this trick, and next day had full operation. 

I knew of this trick and used it for both of my brake m/c's but I wasn't sure about the openings and flow of fluid inside the clutch m/c, I'll definitely give that a go a few nights before I close things up.

Tks

Kelly

[80CX100]

7 minutes ago, gstallons said:

Kelly , whatever you do , you keep this device dedicated to brake fluid ONLY . No mixing brake fluid with any petroleum products . 

 Good luck . When Ford first started using hydraulic clutches on trucks , there was NO procedure that worked 100 % of the time . 

My mcgyvered reverse engineering prime pump failed miserably, but I did make serious headway today; attacking it a different way. 

I digested a ton of info from this site last night, and I think it was you in other posts had mentioned using gravity to move the bubbles along; that really helped, a lot!

After 1 whole day of just seeing clear fluid with no bubbles, I tried what you had suggested elsewhere and filled up the m/c reservoir and opened up the bleeder nipple and let gravity move the fluid and air along; sure enough once I closed the bleeder nipple, worked the lever and pressurized the line, I started to bleed out air again.

I worked this technique back and forth, once I wasn't seeing air from the bleeder, I'd fill it up again, open up the bleeder, let gravity move things along for a while, then repeat, I've gotten a lot of air out of it, and starting to feel some resistance, but I don't think I'm back up to full pressure yet.

Tks

Kelly