Corvair Center Forum : Corvair Center Phorum
Re: Hydraulic Clutch
Posted by: JohnVan ()
Date: November 08, 2018 03:00PM
I've had 3 Honda motorcycles now that came with Hydraulic clutches. Its been my experience that these were very difficult to bleed, but once you did that, they did not give much if any problems in the long run. Bleeding them though was an experience that was filled with lots of cussing and frustration.
Overall the easiest thing I've found to bleed hydraulics is pressure. I've used mity-vac bleeders for years, and have one now but they have problems sealing around the bleeders, and pull air in around the bleeder threads. The end result being that one has to bleed, not until there are no more bubbles, but until you've run enough through the system to think its purged.
I did try the bleeder valves with the check-ball. These worked well enough, but that was on a system that was not entirely dry.
I've got a 1981 International Harvester S-1724 dump truck. These are all hydraulic brakes with a "hydro-vac" booster. Single cylinder master and very long lines. I was able to fashion a pressure bleeder using a simple garden sprayer and an intermediate bottle of brake fluid. This worked incredibly well. The key is sealing the system at the master cylinder. I was able to find a large rubber stopper that fit snugly.
I tried using my pressure bleeder on my Chevy 1500 pickup and ended up with brake fluid squirting all over the place. I just could not get a good enough pressure seal on top of the master cylinder.
I think if I ever do try to convert the viar to a hydraulic clutch, I'll use an external slave cylinder I can get to. I'll have to make a bracket, but that should not be difficult. I'd probably use a master that has a remote reservoir like the one on my S-10. That reservoir has a screw top and should be easy to make a pressure bleeder top for. Once in place I've found these systems to go for years without any difficulties. I do have to top off the fluid once in awhile, but not more than once every 2-3 oil changes.
In the mean time, I've got bigger problems to solve. My Clark's order should be in Friday and this weekend I'll be installing new lifters, and getting the engine back in shape for daily driving. Got all new heater hoses too, just in time for cold weather. Got a "ultimate" shifter rebuild kit, but I think that will have to wait until I see how road worthy everything is. I did manage to COMPLETELY rebuild the brakes with new everything including a new Master cylinder, wheel cylinders, drums shoes springs etc. New bearings and races in the front hubs too.
John Van Valkenburgh
'65 Corsa 140
Re: Hydraulic Clutch
Posted by: thewolfe ()
Date: November 08, 2018 03:38PM
The wilwood slave cylinders are very easy to bleed and you don't need any special equipment. Bench bleed the master then bleed the slave like you're bleeding a wheel cylinder. I know some hydraulic throwout bearings and slaves are a pain to bleed but that's not the case here. I did replace the bleeder valve with a speed bleeder so I can bleed the thing in a matter of minutes.
65 Corsa 180