Making a RH Front Brake Caliper -H1 & H2

Our Denco CR90 project is getting a second front disc. I know there are lots of modern calipers that can dramatically improve brake performance but I want our H2 to look period correct, by modifying a stock caliper. Switching the caliper to the right side is simple. Modifying the bleeder hole to accommodate the brake pipe is the biggest challenge. Here's how I did it:

These are the finished pieces from a caliper I restored/rebuilt a while back. This is to show all of the new parts that go into a caliper rebuild.

This is what was the bleeder screw hole. It must be drilled twice. The first hole is for the small cone shaped seal that fits inside the flanged end of the brake pipe. The second hole is larger and must be threaded to allow the brake pipe to be tightened.

This picture of the newly drilled and tapped (threaded) inlet for the brake pipe shows the smaller hole.

The cone shaped piece can be carefully removed by tapping lightly from behind with a thin rod or punch. I have pressed it into place and used some red loctite for insurance. This side is now ready.

This was the brake inlet hole but now it will become a bleeder hole. I had an insert that is threaded on the inside and on the outside to fit into the hole and allow the bleeder screw to be used. This is a very special part that is not easy to make but there is a simple alternative. Most auto parts stores sell 10mm bleeder screws that will fit right into the original hole, making the whole job a lot simpler. I have never been the type to take the easy road.

The sleeve is no installed in the caliper. I also used red loctite. As you can see there is some of the insert protruding that will have to be filed down.

I am doing 2 calipers so my '72 H2 can also have dual discs. This image simply shows how much smaller the new bleeder hole is.

The insert has been filed flush with the caliper. I might fill the area to make it smooth although it doesn't really show once the bleeder screw is in place and even less after the caliper is painted.

Another picture of the sleeved bleeder hole.

With the bleeder screw installed it is difficult to tell that this is a modified LH caliper.

All done! Now I can apply the black paint to both sides of the calliper. I didn't show the back because it required no modifications. When it is dry, the piston and seals can be installed and the two halves put together.

You can modify a LH caliper bracket but I chose to use a new one from our stock. I'll post more pictures once the caliper is painted and assembled.

Painted the caliper today. Got a nice smooth finish. Not too shiny. Not too dull.

I'll let the paint cure for a few days, then I can put it all back together.

All done! With it's new piston, seals and pads, my newly rebuilt/modified RH caliper should work as well as it looks.

I should also mention the caliper bolts. They are original bolts that were re-zinc plated and not new.

I wanted to see what it would look like if I took the easy road and simply installed a $2 M10x1.25 brake bleeder from the local auto parts store on my second RG caliper. Here is the auto part next to a genuine Kawasaki bleeder. What a size difference!

The 10mm bleeder installed in the caliper. It doesn't look terrible and I can see why people would choose this simple solution. Those who aren't concerned about making their right caliper look like the rare original Kawasaki part can do the entire conversion in an afternoon in with a drill press, 10x1.25 tap and basic tools.

My opinion… It works. It's inexpensive. Time fabricating a sleeve to fit an 8mm bleeder in a 10mm hole. No, it doesn't look as nice but not everyone cares. Both calipers will work the same but one looks better. I'll do the extra work for the sake of aesthetics but it isn't really necessary.