I Can't Get Pressure On Master Cylinder Rebuild

[86er]

OK, I've got a problem with the clutch on my 86! I rebuilt the master cylinder and when I got it disassembled, I found that the kit that I got was the wrong one. I took that back to the shop I got it from (independent guy that I use) along with the old parts. He found what appeared to be right (Yami # 2KW-W0099-00) and swapped with me.

 

I came home and put it back together. Now it won't build any pressure. I have tried:

 

1) Putting fluid in from bleeder with a syringe. At first I got a few little bubbles in the master, now it won't take it at all thru' the bleeder even with lots of pressure.

 

2) Cleaned and cleared the bleeder, then Teflon taped it. It didn't drip much with the bleeder out either.

 

3) Bleeding the old fashioned way, with LOTS of pumping. It will push a little thru but not much, and I have gone thru at least 5 reservoirs full.

 

4) Using a mighty vac to suck it thru the bleeder.

 

5) Disassembled and reassembled master to make sure all parts are in the right order.

 

6) Tied the clutch lever back overnight to allow air to come up.

 

7) Left clutch lever alone overnight to allow air to come up.

 

8) Pulled out some of what little hair I have left!

 

:confused07:

 

I've thought of getting all the fluid out that I can and then blowing air through it from both ends. That does sound messy though! Any ideas out there? (Relating to my clutch issue that is!) Does anyone recognize that part number? I'm wondering if the size is off just a fraction. It was snug going into the cylinder.

 

Tuesday I'm gonna call my dealer and check their number.

 

This problem is so bad that I had to borrow and ride a V-Rod to Hootor's Bike Night on Thursday night!

 

 

[utadventure]

Todd-

 

I looked at the parts list on mrcycles.com and the cylinder kit listed there for the clutch is the same as the part your mechanic sold you. There may be a defective part in the kit or (unlikely) that they were installed in the wrong order.

 

No great answers here but I wish you the best of luck.

 

Dave

[86er]

You're right Dave. I guess I should have looked at that before I posted! I thought they had their own numbers!

 

When I did the slave cyl. It took a long time to get bled but not this long!

 

 

[Marcarl]

http://parts.yamaha-motor.com/partimage.gifx?d=41342,2,0

kit # from yamaha 2KW-W0099-00-00

Hope this helps. maybe not.

Seems you either have some air blocking the process, a blockage in the line, maybe a kink, or the parts are not in the right order or facing the right way. You sure did give it an honest effort though with all that you've done. If you did not clean the slave, then I would suggest doing that as well. A lot of crud can collect in the slave and cause a host of difficulties.

[Guest KitCarson]

OK, I've got a problem with the clutch on my 86! I rebuilt the master cylinder and when I got it disassembled, I found that the kit that I got was the wrong one. I took that back to the shop I got it from (independent guy that I use) along with the old parts. He found what appeared to be right (Yami # 2KW-W0099-00) and swapped with me.

 

I came home and put it back together. Now it won't build any pressure. I have tried:

 

1) Putting fluid in from bleeder with a syringe. At first I got a few little bubbles in the master, now it won't take it at all thru' the bleeder even with lots of pressure.

 

2) Cleaned and cleared the bleeder, then Teflon taped it. It didn't drip much with the bleeder out either.

 

3) Bleeding the old fashioned way, with LOTS of pumping. It will push a little thru but not much, and I have gone thru at least 5 reservoirs full.

 

4) Using a mighty vac to suck it thru the bleeder.

 

5) Disassembled and reassembled master to make sure all parts are in the right order.

 

6) Tied the clutch lever back overnight to allow air to come up.

 

7) Left clutch lever alone overnight to allow air to come up.

 

8) Pulled out some of what little hair I have left!

 

:confused07:

 

I've thought of getting all the fluid out that I can and then blowing air through it from both ends. That does sound messy though! Any ideas out there? (Relating to my clutch issue that is!) Does anyone recognize that part number? I'm wondering if the size is off just a fraction. It was snug going into the cylinder.

 

Tuesday I'm gonna call my dealer and check their number.

 

This problem is so bad that I had to borrow and ride a V-Rod to Hootor's Bike Night on Thursday night!

 

 

I think that is what the problem is, you have went to Hooters too much, you have went blind...cannot see. :rotfl::stirthepot:

[Venturous Randy]

I had a problem a few years ago on my 83 with the clutch lever getting stiff. I went thru everything and finally found that the metal part of the clutch line that goes under the engine was glogged. I cleaned it out and everything works fine. If yours is clogged, it would keep it from getting the flow to allow bleeding.

I would also try taking the hose loose at the master and putting your finger over the connection and seeing if you can get to work as a check valve. Just make sure you got everything covered up good if it sprays.

RandyA

[hmoc75]

had a simular problem on a ford pu....changed the master cylinder and still wouldn't pump up. finally found the problem it was a pin hole in the line. changed that outand it worked great. could be something stupid like that.

[GeorgeS]

Double check in bottom of Resovoiur, there are two small holes. Double check that these are free. Also you might remove the Line at top and and at the Slave cylinder, blow out with air to make sure its not plugged.

 

I made the mistake of installing one of the rubber seals in the master " backwords " had to take apart and start over. But its was still a battle to get it working.

[86er]

The holes are clear, George, I checked them by blowing air through them when I disassembled it the second time.

 

What about removing the line at the master and blowing air through the bleeder hole in the slave? I've thought about doing that but, man, it's gonna be messy! Besides, if the line is blocked, it seems like it would build pressure and not bleed!?! Instead, it has a loose lever.

 

[GeorgeS]

well I meant removeing the hose at master, and Slave, and just blowing out the hose. As the other fellow said, he found his line plugged. I would not blow high pressure into the " Slave Cylinder "

 

I watched " Condor " bleed a clutch at Ft.Collins last year. He used a Syringe with a piece of Hose, to " Slowly pump fluid " into the system from the Bottom at the slave up into the master, Do this Very slowly. Watch the Resovoiur fill up, keep slowly pumping fluid in from the bottom untill no more air bubble come out.

 

Then, revert back to pumping the handle. and rebleed at the Slave position.

 

I always use Valvoline synthetic brake fluid.

[86er]

I did the syringe thing and got a few small bubbles in the master but then it wouldn't take any more fluid even with as much pressure as I could put on it. That's what makes me think that there could be a blockage!? But again: Why won't the lever have any pressure if it's blocked???

 

I didn't mess with it today, decided to give it a day to see if it would heal itself!

 

And yeah, I like the Valvoline. I've been using it ever since my clutch fluid boiled on me and I had no clutch. Changed all the brake and clutch fluids on both bikes to it.

 

[derwood]

bench bleed the master first,...bench bleed the master first,... to determine if that is the problem, having the slave and the line in the circuit just gives you 2 more variables, do one step at a time. If the steel line is pinched or coroded and blocked the lever may not build pressure because you canna get the air out.

[GeorgeS]

If we assume, the Master is All OK.

 

And the Line is clear, then there might be a blockage Inside of the

" Slave Cylinder itself "

 

Have you ever worked on the Slave cylinder?

 

OK, two approach's to this. You can get a rebuild kit, for about $15 bucks, OR a complete new Slave Cylinder for About $30 bucks.

 

I reccomend buying a new one, as its worth the $15 to not rebuild the old one. And it will probably work better.

 

On an 86, if its never been redone, it needs a new one !!!!!

 

I did mine two years ago, it was full of #$%*@

[86er]

Did the slave last fall. I also replaced the lower hose that goes into the slave cylinder. But like I said, I can't push fluid from the bleeder up the system so there could be a restriction.

 

I like derwood's (weren't you on Bewitched?) idea of bench bleeding. Someone else also mentioned essentially the same thing, saying to bleed it at the banjo bolt.

 

[Squeeze]

I'd dismount the Bleeder Valve, open the Master and putt some Rags inside and around the Master, let a Helper hold them in Place and carefully blow Air into the Bleeder Hole to assured the Line is not clogged.

 

Then, i would fill the Master half way with Fluid and wait until it's seeping out at the Bleeder Hole. Then mount the Bleeder Valve, fill the Master and try to bleed it another Time. If it's going to Work, fine. If not, I'd elevate the Master to the next level of Existance.

 

forget to mention it at first ...

 

make sure, that the Line has absolutly no Bend upwards. The Reservoir has to be the highest Point in the System.

 

If you mounted the MC somehow in an upwards Angle, losen it at the Bar and turn it in a Way that the Line is always turned downwards. Once you got a upwarded Bow in the Line, you will go crazy and not get it proper bleeded for Years.

[GeorgeS]

Did the slave last fall. I also replaced the lower hose that goes into the slave cylinder. But like I said, I can't push fluid from the bleeder up the system so there could be a restriction.

 

I like derwood's (weren't you on Bewitched?) idea of bench bleeding. Someone else also mentioned essentially the same thing, saying to bleed it at the banjo bolt.

 

 

Possible some blockage has migrated down into the line, or Slave dureing the rebuild and rebleed process ??

[86er]

I tried bleeding at the banjo bolt to no avail (and no air there). I tried the air technique from the bottom. The flair nut didn't want to break loose so I took out the bleeder and used a syringe to blow air up, with the banjo bolt in a gallon baggie. Good looking fluid came up. When I started getting just air, I used compressed air easy. It all seemed clear. I blew into the master to check the small hole and it was clear. (That's where I screwed up and blew a mist of brake fluid out on the bike! I spent the next ten minutes and a lot of brake clean and plexus cleaning that up!)

 

I put the banjo and bleeder back on and put fluid in with the syringe through the bleeder until it came out in the master. I found that the bleeder had to be many turns out for the fluid to go in easily. And yes, I did check the bleeder to make sure it was clear too. Still no pressure.

 

Now, the kit that I got from my local independent guy had the right numbers and looked right, but had been opened and stapled shut so today I called Buckeye and Rick is sending me the right kit tomorrow! I'm hoping that the kit is bad. Guess I'll be riding the Intruder for a few days!

 

[86er]

I got the new master cylinder kit from Buckeye Performance in the mail today, I pulled the master off and took it apart (I'm getting really good at that now!) and put the new guts in it. I put it back on the bike and put fresh fluid in it from the bottom bleeder until it filled the reservoir. A lot of air came out the little hole in the master. I held my breath and pulled the lever back and guess what?!? NO PRESSURE! Geez louise! I bled it at the banjo bolt, but got no air there. I started bleeding it the old fashioned way and noticed that it did push out more fluid than before. I went through 4 or 5 reservoirs full and still nothing. I went off and did some other stuff and fumed a while.

 

I thought about leaving it until tomorrow. Decided to try bleeding a little longer. It felt like it was getting a little firmer; or was my wrist getting a little weaker? Then two big air bubbles popped out! Kept going and got more and more air! Finally got it real firm but the lever still is not out as far as it should be. I can put it in gear, on the center stand, hold the clutch in and I can't spin the rear wheel with my foot. I put it back on the ground put it in gear, held the clutch in and started it. It jumped just a little but was easy to hold. It feels about the same as when I rebuilt the slave and had to bleed it. I figure I'll ride it for a few days and bleed it some more. But heck, I've already been through 1/2 jug (the BIG jug) of Valvoline synthetic fluid!!!

 

I'm still not sure exactly what was wrong, maybe it was air all along, maybe it still has air in it, but at least it's ridable again! Thanks to all for the advice, emails and things to look for.

 

[GeorgeS]

Maby its " Bad Air "

 

Caused by Global Warming, and all that stuff

 

However, I went thru just about the same process, but just did not take quite as long.

 

I ended up with it working, but not really perfect.

 

As time went on, it seemed to get better. A rebleed it every couple weeks, and eventually was OK.

[86er]

Did you continue to rebleed it every few weeks, George? How long did it take to get it right? And about how much fluid did you bleed each time?

 

[GeorgeS]

Not much fluid, each re bleed.

 

Also, I got the impression that the New Rubber Seals, might have needed some time to Seal, or Seat in.

 

However thats a subjective observation.

 

Just so you know, many folks have had about the same problem, getting the system bleed out.

 

Check thru the maintenance section, you will find many postings on the subject.

 

One other thing, did you replace the Slave Cylinder??? Everybody that takes them out seems to find a lot of Crud in them. I know I did.

Did mine about 2 years ago. same time I did the master.

[Cutty]

Remove clutch handle and check brass bushing that pushes push rod into m/cyl for wear. This is bushing should be a perfect fit in the handle, if not replace. Honda, Kaw and Yam all use the same bushing. With m/cyl mounted on handle bar, put finger over line hole and bleed. Once you feel pressure there install bolt and with a helper gently clamp off brake hose approx 1 inch from hose banjo. Start bleeding by loosing banjo bolt and before clutch handle reaches handle bar tighten bolt and repeat this until you have full pressure with line still clamped. Once you have pressure release and reclamp line, do this until complete system is under pressure with clamp removed. While under pressure bleed slave cyl. Any brake fluid, gasoline and acid on painted areas should be flooded with water as a neutralizer.

[Gone14S]

bench bleed the master first,...bench bleed the master first,... to determine if that is the problem, having the slave and the line in the circuit just gives you 2 more variables, do one step at a time. If the steel line is pinched or coroded and blocked the lever may not build pressure because you canna get the air out.

 

I agree with the above.

Every bike I have reworked the brakes on will not pump up until you bleed the master cyn. off first.

If you have the right parts and it is assemble right you should have pressure after you bleed the master first.

You can do this right on the bike.

Fill the master up. pump the handle a couple of time and crack the bango nut loose right at the master. You should get air bubbles. do this a couple of times. You should start to feel back pressure at the handle. You should be able to bleed the brakes now.

If you do this while on the bike just keep a shop rag. wraped around the master cyn.

 

Kurt

[86er]

I rebuilt the slave cylinder in Aug of last year, So it is good. After riding about 450 miles this weekend, it seems a lot better. Assuming that over time any air will rise to the top of the system, it should disperse itself thru the return hole in the master, correct? I think I will try bleeding the master at the banjo bolt periodically. I like the idea of clamping the hose.

 

I'll also try replacing the brass bushing and maybe the pushrod, as that whole set up seems loose. Loose enough that it's hard to keep the cruise set and I was wondering how to fix that as well. I was going to add a longer spring to push the lever back out.

 

[Squeeze]

Just keep the Lever pulled over Night for the next few Days with Zip-Tie or a Wire. The last Bubbles will come out every Time you release ait in the Morning.