Clutch master bad??

akadaryl33 · June 17, 2013, 02:58:16 PM

So i just rebuilt my carbs over the winter and put everything back together. I went to take her out for a test run and found out i have no clutch. I pull the lever and nothing is happening, so after cruising this AWESOME repository of knowledge, i decided that it was probably my clutch slave cylinder. I ordered a rebuild kit from RPM ( thanks for the 1 1/2 day turnaround!!!) and popped it off and swapped out the seals and spring. I bled the system, and bled the system, and bled the system... Nothing. The clutch never seems to develop any pressure in the system, the lever is still limp. So now i am wondering if anyone has any input on whether i should rebuild my clutch master cylinder? Its worth noting that when i went to drain the system before i pulled the slave off, i could not get the master drained by pumping the clutch lever. I had to soak it out with some paper towels. I was just wondering if that proved that my master cylinder is not pumping as it should? I appreciate any input you guys might have.

Josh

fintip · June 17, 2013, 03:12:05 PM

I'm no pro at this, but, assuming you rebuilt and CLEANED the slave properly, [edit: and BLED it properly as pointed out below...]

1. Not being able to develop pressure at the master would mean the master needs work, so yeah, that symptom lines up.
2. There's not much else in the system, so it's probably the master just by process of elimination.

No chance you tried to start the bike while the clutch slave was off, is there? Just checking, I don't know what symptoms develop when that part is absent, but you probably would have mentioned if a spear shot out of your bike.

jscgdunn · June 17, 2013, 03:21:14 PM

A questions on you bleeding procedure: did you have the outlet tube rising from the bleeder and did it have any fluid in the tube? If not it will suck air back in on the return stroke. Also you may want to try injecting fluid in through the bleeder hole to push the air to the master; a large syringe works. I also used a small pump that is used for putting gear oil into the lower unit of an outboard motor.

Be sure the cover is on loosely or you will have fluid everywhere. In my experience so far...if the master is bad it will leak a bit.

fintip · June 17, 2013, 03:26:01 PM

I always just tighten the bleeder before I release the lever, so the return stroke can't pull anything back in... Or am I misinterpreting what you said? I thought that was just how it was done, I can't imagine how it could suck anything back in this way except for the piston.

jscgdunn · June 17, 2013, 03:44:18 PM

If you elevate the tube above the master and it has a bit of fluid in it, it cannot suck air...you would not need to tighten/loosen each pump. Usually enough fluid will enter the tube on the first stroke; I always try to have some in the tube to start.

akadaryl33 · June 17, 2013, 03:52:26 PM

Thanks for the quick replies!!! I believe i did reassemble the slave correctly ( with a little help from Mr. Clymer), and i was also sure not to start the bike with the slave off. LOL i have seen the comical posts about this on here in the past. I had my Dad help me with the bleeding process, we were sure to close the bleeder screw each time before i released the lever to avoid sucking anything back in. I was never able to get enough fluid to come out of the bleeder to fill the tube, just small amounts. Looks like i need to hit Randy up at RPM again and order the master rebuild kit. Thanks again!!! One more thing, have any of you rebuilt the slave with one of RPM's kits? It had one more plastic oring in it than what came off the bike. It was smaller than the others and made of a harder compound (not rubber), im just not sure what this is. Does this kit do multiple bikes?

Josh

jscgdunn · June 17, 2013, 04:02:44 PM

Hi Because you noted it was so difficult to bleed, you may want to try the two techniques I mentioned...I have found that these systems are much more difficult to bleed than a car. Even a very small amount of air will give you "no-clutch".

akadaryl33 · June 17, 2013, 04:13:54 PM

I will give the bleed another try. I did notice some moisture under the master before i started all this. It was such a small amount that i just shrugged it off though, seems more important now... It never dripped it was just a little wet by the piston, im leaning towards the master being bad. Thanks everyone for the advice.

racerrad8 · June 17, 2013, 04:34:19 PM

Quote from: akadaryl33 on June 17, 2013, 03:52:26 PM
One more thing, have any of you rebuilt the slave with one of RPM's kits? It had one more plastic oring in it than what came off the bike. It was smaller than the others and made of a harder compound (not rubber), im just not sure what this is. Does this kit do multiple bikes?

Josh

Josh,

The kit is Yamaha specific. There should have been five (5) parts in the kit. The slave seal, dust boot & spring. The bleeder screw cover and the clutch pushrod seal for the block.

Take a look at the photo on my website and let me know which part you are inquiring about.

Randy - RPM

fj11.5 · June 17, 2013, 05:32:46 PM

The small seal is for the clutch push rod

Travis398 · June 17, 2013, 05:55:38 PM

Josh,
I would guess the master is fine. I had a similar problem I used a vacuum pump to suck the fluid into the system.
I tried pumping the lever for a while before I gave up. Like you I thought the master was bad, but once I got fluid in the system it worked fine.

I also did the zip tie trick on the lever over night that helped some too, despite my skepticism.

akadaryl33 · June 17, 2013, 07:10:53 PM

Thanks for the info on the pushrod seal Randy. Is it possible that the old one completely disintegrated? I did not remove one from it when disassembling.... Now I feel really stupid lol i would assume that my problems begin and end with the extra part sitting on the work bench.

racerrad8 · June 17, 2013, 07:42:52 PM

Quote from: akadaryl33 on June 17, 2013, 07:10:53 PM
Thanks for the info on the pushrod seal Randy. Is it possible that the old one completely disintegrated? I did not remove one from it when disassembling.... Now I feel really stupid lol i would assume that my problems begin and end with the extra part sitting on the work bench.

No, that seal is separate from the slave cylinder, it is the seal in the block at the pushrod.

Randy - RPM

rktmanfj · June 17, 2013, 07:49:52 PM

I've known more than a couple of people who have installed the slave piston seal backwards, then wondered why it wouldn't bleed.

I did it myself once, but caught it before putting things together.

akadaryl33 · June 17, 2013, 10:21:13 PM

Well i am feeling more than a little foolish about the pushrod seal. I will pull it all apart tomorrow and try again with the proper parts installed, and give it a go again. I found the pushrod seal in my Clymer under the clutch section. There was no mention of it in the slave cylinder section. Randy if you happen to see this, would the lack of a new pushrod seal possibly cause the problems i am experiencing. FWIW i procured a vacuum bleeder to use tomorrow too.

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Clutch master bad??