Bad master clutch cylinder?

[Mjbell72]

I've been searching this forum but I didn't find the exact situation I am dealing with.

I recently purchased a 1990 Voyager 12 with about 57k on it. When I went to test it I literally had no clutch disengagement, it stalled out the second I put it in gear. We quickly found that the master cylinder was bone dry, added fluid and bled the slave cylinder and then it had a clutch again. I did obviously question how it was empty. The owner had not ridden it for a couple years, so I suspect that had something to do with it. In any case after we bled it out I could find no sign of fluid leaking anywhere along the path of the system. When I initially took off the clutch was grabbing very close to the handlebar and at one point did not want to disengage the clutch. After pumping on it for a bit it seemed to come around and I was able to drive it 30 min home without issue.

The clutch engaging so soon troubled me so I did go through the process of flushing it all out and bleeding it again. After doing that it seems a bit hit or miss. The clutch is engaging a bit later but it seems like the master cylinder does not always pressurize along its full stroke and again at one point it killed the engine. After pumping again, it worked again. Im inclined to believe the problem is my master cylinder and not the slave. If I sit at a stop it seems to hold fine, no loss of pressure allowing the clutch to engage and will take off just fine.

I have ordered a replacement master cylinder. It would see logical to me given the facts that it will disengage, and the clutch does not slip when engaged that I must have some blow by on the master cylinder causing it to not move the slave cylinder consistently and therefore causing early engagement. I have to say that the slave cylinder reservoir is pretty gummed up from going dry. I cleaned it the best I could and the 2 holes, but it only seems to work right when it wants to.

In any case, I think this seems like the logical problem, but I was hoping for some confirmation from someone on this forum. I have ordered an aftermarket clutch cylinder on Amazon and as far as I can tell it should be compatible.

https://www.amazon.com/gp/product/B09Y3 ... THQDI&th=1

Thanks in advance for any advice. Looking forward to riding this summer.

[Van Voyager]

Sounds like you have air in the system. These dual disk systems with a splitter can be a PITA to bleed properly. Bolt bleeding at every junction can help eliminate air from sticking in the corners at the banjo bolt interface.

And, you can probably still get rebuild kits for the OEM master cylinder (if it needs one).

[Mjbell72]

Sounds like you have air in the system. These dual disk systems with a splitter can be a PITA to bleed properly. Bolt bleeding at every junction can help eliminate air from sticking in the corners at the banjo bolt interface.

And, you can probably still get rebuild kits for the OEM master cylinder (if it needs one).

I think you misread my post. The brakes work fine it my hydraulic clutch that is giving me grief. I'm pretty convinced it's the master cylinder. I flushed and bled it using a vacuum bleeder so I'm pretty confident I got the air out. Pretty sure its blowing by in the master. Just tried it again this afternoon and I couldn't even put it into gear with the bike on the center stand. Pumped the heck out of it and got it to work one time. As much sludge as I found in there, I have a pretty good feeling its FUBAR.

Thanks for the reply.

[Van Voyager]

Sounds like you have air in the system. These dual disk systems with a splitter can be a PITA to bleed properly. Bolt bleeding at every junction can help eliminate air from sticking in the corners at the banjo bolt interface.

And, you can probably still get rebuild kits for the OEM master cylinder (if it needs one).

I think you misread my post. The brakes work fine it my hydraulic clutch that is giving me grief. I'm pretty convinced it's the master cylinder. I flushed and bled it using a vacuum bleeder so I'm pretty confident I got the air out. Pretty sure its blowing by in the master. Just tried it again this afternoon and I couldn't even put it into gear with the bike on the center stand. Pumped the heck out of it and got it to work one time. As much sludge as I found in there, I have a pretty good feeling its FUBAR.

Thanks for the reply.

No misread - just a Sr. moment answer. . Air in a hydraulic clutch circuit causes the clutch to be grabby or not release at all. One of the places air gets trapped in at the ends of the banjo bolts, so bolt bleeding will clear that up.

You mention gunk - Make sure the two holes in the MC reservoir are unplugged, If the larger hole is plugged, fluid can't get into the hydraulic circuit and your clutch won't disengage (which seems to be what's happening in your case). If the smaller hole is plugged, your clutch won't engage.

The other thing that can help is to position the bars so that the left bar is up as high as possible (i.e. the lever end of the MC is higher than the banjo bolt end) Pull the lever in as far as it'll go and let it flick back, repeat, repeat, repeat. This helps clear small air bubbles from the MC piston tube (if you pull the cover off while doing this, you'll probably see the air bubbles coming out of the MC reservoir holes).

[cushman eagle]

And,also,please cover the fairing with plastic sheeting Brake fluid does not play nice with the plastic of the fairing
That is true whether clutch or blake service!

[Mjbell72]

Sounds like you have air in the system. These dual disk systems with a splitter can be a PITA to bleed properly. Bolt bleeding at every junction can help eliminate air from sticking in the corners at the banjo bolt interface.

And, you can probably still get rebuild kits for the OEM master cylinder (if it needs one).

I think you misread my post. The brakes work fine it my hydraulic clutch that is giving me grief. I'm pretty convinced it's the master cylinder. I flushed and bled it using a vacuum bleeder so I'm pretty confident I got the air out. Pretty sure its blowing by in the master. Just tried it again this afternoon and I couldn't even put it into gear with the bike on the center stand. Pumped the heck out of it and got it to work one time. As much sludge as I found in there, I have a pretty good feeling its FUBAR.

Thanks for the reply.

No misread - just a Sr. moment answer. . Air in a hydraulic clutch circuit causes the clutch to be grabby or not release at all. One of the places air gets trapped in at the ends of the banjo bolts, so bolt bleeding will clear that up.

You mention gunk - Make sure the two holes in the MC reservoir are unplugged, If the larger hole is plugged, fluid can't get into the hydraulic circuit and your clutch won't disengage (which seems to be what's happening in your case). If the smaller hole is plugged, your clutch won't engage.

The other thing that can help is to position the bars so that the left bar is up as high as possible (i.e. the lever end of the MC is higher than the banjo bolt end) Pull the lever in as far as it'll go and let it flick back, repeat, repeat, repeat. This helps clear small air bubbles from the MC piston tube (if you pull the cover off while doing this, you'll probably see the air bubbles coming out of the MC reservoir holes).

Thanks for that advice, I will try that. certainly cant hurt.

[Mjbell72]

And,also,please cover the fairing with plastic sheeting Brake fluid does not play nice with the plastic of the fairing
That is true whether clutch or blake service!

Yup, definitely heard about that situation.