Vulcan Master Cylinder Rebuild

The hydraulic clutch master cylinder on my 2003 1500 Classic quit pushing fluid to the slave cylinder. That's not good. Rebuilding a master cylinder is not unusual in general, but I haven't run across any accounts of a Vulcan M/C quitting or how to do a rebuild on one, so here goes.

I bought the parts from the local Kawasaki dealer. This kit fits a bunch of brake master cylinders, too, so they actually had it in stock. Looking at the Clymer manual already has me concerned. The parts look a bit different from the picture so we will see how this goes.


I already had the MC off the bike on the bench. Here's the next difference of note between the book and what's in my hand. This MC is marked 14, I assume for a 14mm bore.


The book picture shows marked as 1/2. I assume that's a 1/2 inch bore. The books says remove the clutch switch, but I'm going to see if I can perform the rebuild with the switch still on the housing.


Remove this nut on the lever pivot bolt.


After the nut is off you'll still need to unscrew the lever pivot bolt.


Bolt and lever come off. Kind of a mess from the DOT 4 leaking everywhere.


Dust boot and rod pulled out.


Remove this snap ring.


Washer, piston with seal, cup, and spring come out. Luckily these parts look exactly like the parts I bought.


The piston seal is kind of a u-ring with the u part toward the spiral part of the piston.


Lube the new parts with DOT 4.


Spring and cup go back first.


Work the seal on to the piston.


Yeah, that's a tight fit and a lot work for something so simple.


Piston and seal go back in.


Washer next. Then the snap-ring. It's hard to get a picture of the snap ring going in. You have to push it all down and use snap ring pliers. I don't have a third hand to hold the camera.


Dust boot and rod next. This picture is backwards, the rounded end of the rod goes toward the piston and the flatter end goes to the lever side.


This piece goes into the lever and rod goes into in it.


My picture taking didn't keep up at this point. Install the lever, lever pivot, and jam nut. Put the MC back on the bike and connect the banjo bolt with new sealing o-ring. Then you need to fill and bleed the clutch line. I tried to pump the lever enough to bleed it, but that would have taken days, so just pull the left floorboard and engine cover and bleed it properly.