Member Contributer tomk1960 Posted January 9, 2014 Member Contributer Share Posted January 9, 2014 I'm in the process of refinishing and rebuilding the entire brake system on my VF1000F and I'm also rebuilding the clutch master cylinder and slave as well. New braided lines will be installed and then I plan to use DOT5 fluid going forward. This is the first time that I'll be bleeding a clutch system and wanted to know if there are any pitfalls involved since there'a a master and slave cylinder. I always prime the master cylinder before I start bleeding and I'll push the slave's piston all the way to limit the amount of air trapped in there. Should I expect any issues? The service manual just says to fill the reservoir and bleed the system, so that tells me nothing... Thanks. Link to comment Share on other sites More sharing options...
Member Contributer YoshiHNS Posted January 9, 2014 Member Contributer Share Posted January 9, 2014 What more do you want? It's pretty much the same as brakes. Put fluid in the reservoir. Bleed at the slave. Why are you going to run DOT5? Link to comment Share on other sites More sharing options...
Member Contributer tomk1960 Posted January 9, 2014 Author Member Contributer Share Posted January 9, 2014 What more do you want? It's pretty much the same as brakes. Put fluid in the reservoir. Bleed at the slave. Why are you going to run DOT5? A thread in the naked Gold Wing forum talked about how the hydraulic clutch systems were a major hassle to bleed, so of course I wondered if the VF's have issues. Thanks. Just checking. I've been using DOT5 for years in all my bikes as I restore them. It doesn't attract moisture and doesn't attack paint if spilled. There are pros and cons to DOT3 and DOT5, but since I've had excellent results running DOT5, I'll continue down that path. Link to comment Share on other sites More sharing options...
Member Contributer YoshiHNS Posted January 9, 2014 Member Contributer Share Posted January 9, 2014 I used a mityvac to help with bleeding the lines. Makes it easier to get the fluid flowing. I had to use teflon tape on the bleeders for the car because the mityvac was sucking air around the threads instead of pulling from the reservoir, but that was the only hassle I've had bleeding dry systems. Link to comment Share on other sites More sharing options...
Member Contributer tomk1960 Posted January 9, 2014 Author Member Contributer Share Posted January 9, 2014 I think the biggest issue that most people have when bleeding a freshly rebuilt system is having an airbound master cylinder. If it's primed before you connect it, bleeding goes very quickly without the need for any special tools. In a future video, I plan to show the technique I use to prime the MC using no tools whatsoever that gets me from start to finish in about 20 minutes. Thanks for pointing out to me that the clutch system is just like the brake system. (I.E. the slave is basically the same as a caliper.) For some reason, my brain wasn't seeing it that way. Link to comment Share on other sites More sharing options...
Member Contributer CBVFRbikeboy Posted January 9, 2014 Member Contributer Share Posted January 9, 2014 Hi Tom. I seem to remember the manual mentioning a spacer to prevent the lever being pulled back too far, but haven't got it with me. There's a similar procedure for the vf750: Not sure what the consequences of 'piston overtravel' are, but I haven't come across this with any brake system? cheers ian Link to comment Share on other sites More sharing options...
Member Contributer tomk1960 Posted January 9, 2014 Author Member Contributer Share Posted January 9, 2014 Hi Tom. I seem to remember the manual mentioning a spacer to prevent the lever being pulled back too far, but haven't got it with me. There's a similar procedure for the vf750: Not sure what the consequences of 'piston overtravel' are, but I haven't come across this with any brake system? cheers ian Hi Ian, I just looked through the FSM for my VF and there's no mention of the spacer you show. Perhaps that was an update to later editions? I'm not sure why a spacer would be needed, but maybe someone here on the forum knows. It would be no problem to use one if necessary. Thanks! Tom Link to comment Share on other sites More sharing options...
Member Contributer CasualSwede Posted January 10, 2014 Member Contributer Share Posted January 10, 2014 Generally speaking, you don't want to use the full lever travel because you run the risk of pushing the master cylinder piston out of its smooth bore. I've seen guys ruin brand new clutch master cylinders in their cars by pumping the clutch pedal full stroke, for the first few strokes. Guess it pops the piston out far enough to ruin the o-ring/sealing face. Hope that explanation makes a bit of sense... Link to comment Share on other sites More sharing options...
Lobotomy Posted January 10, 2014 Share Posted January 10, 2014 You could easily ruin the seals in the master by not using a spacer on your handle bar so that the lever does not bottom out against the handlebar. I have used a mighty vac on mine and it will make the job easier. If you already have the slave off the bike, use a clamp to push the piston in and hold it while bleeding, I found that the bleeding went faster this way. When I did it with the slave mounted it took me forever to get all the air out. Just use the spacer for bleeding, then remove. Also be careful when you reattach the slave as it is very easy to strip these bolts. Link to comment Share on other sites More sharing options...
Member Contributer mello dude Posted January 10, 2014 Member Contributer Share Posted January 10, 2014 Generally speaking, you don't want to use the full lever travel because you run the risk of pushing the master cylinder piston out of its smooth bore. I've seen guys ruin brand new clutch master cylinders in their cars by pumping the clutch pedal full stroke, for the first few strokes. Guess it pops the piston out far enough to ruin the o-ring/sealing face. Hope that explanation makes a bit of sense... Another 2 cents on that is if the piston is over stroked, you get fluid on the back side of the piston and your hosed. The only way out after that, is to take it apart clean out, reassemble. The seals may be effe'd too and its rebuild time. I typically tape a small block of wood to the handle bars when I do a bleed job, so I dont get a brain fart and screw it up. Link to comment Share on other sites More sharing options...
MeyekulBayrd Posted January 10, 2014 Share Posted January 10, 2014 Bleed at the slave until you get some resistance then crack the banjo bolt at the master with pressure on the lever. Squeeze the level most of the way and tighten the banjo. Repeat until no air comes out. Link to comment Share on other sites More sharing options...
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