Motorcycle Repair: 84 honda shadow vt700c, clutch master cylinders, clutch master cylinder

Question
hello i have a 1984 honda shadow vt700c  the bike runs great starts right up with no choke has great compression im haveing one problem tho the clutch seems to kinda slip every now and again  iv noticed it leaks some fluid out of top of mastercylinder but clutch handle has same presure as when it works fine but all i have to do is hold clutch handle n and break bleeder valve then close valve then it works for another 50 or so miles depending on how much stop and go i do if can help please email me im quite puzzled on what to do thanks

Answer
Chris, if the master cylinder hasn't been rebuilt/replaced in the last 28 years, it is probably time to go through the whole hydraulic system and replace all the soft parts/seals/o-rings.

The clutch shouldn't be slipping normally, if the hydraulics are good, but if the tiny bleed port in the clutch master cylinder is blocked off/plugged up, then the slave cylinder may hang up on the clutch pushrod, rather than release completely, as designed.

Most all parts for the brake and clutch master cylinders are available from Honda and even from some aftermarket sources. If you still have original hydraulic lines, they should be replaced, as well. Hydraulic fluid will absorb moisture from the air and eventually it gets down into the fluid system. If the water/moisture is near a hot engine part, it can boil and cause a bubble in the fluid system, which gives a soft feel to the lever and lack of travel at the slave cylinder.

I would suggest a system rebuild and then use some DOT 5 or the newer DOT 4 fluid.

Bill Silver