This post is one part, How To Replace The Master Cylinder, and one part How To Earn A Customer For Life.
Let’s start with the last part first.
HOW TO EARN A CUSTOMER FOR LIFE
I’ve been having issues with the rear brake for a while. While riding to Oregon I lost it completely a few times. Pedal all the way to the floor would have no effect at all. After a little bit it would come back. Visually we could see nothing so we thought I might have been dragging my foot on the pedal and boiled the fluid.
Riding on the freeway a few weeks later I lost it again. This time, fluid was dripping off the bottom of the pivot. A quick check of the ADV boards and it’s common to need a rebuild of the master cylinder. I looked online, sourced the part number (#60013061000) and found an online store that had it. That store was Ronnie’s Mail Order. I had never heard of them but they had the part in stock so I ordered it.
The kit arrived and I started to do the simple rebuild. That’s when I saw it. The ‘sight glass’ in the side of the unit was missing. Completely missing! Doh! No rebuild is going fix that.
Missing Sight Glass
Now at this point I can’t say that I wasn’t riding the brakes on the way to Oregon or that the cylinder needed new seals. What I could say for sure is that I needed a complete new master cylinder. Maybe.
Someone on ADV thought I might be able to find replacement sight glass on eBay. It turns out the KTM glass is slightly smaller than the generic Japanese bike glass. Bummer, eh?
Japanese sight glass is 18mm wide
So I went back to Ronnie’s – found the complete unit and was just about ready to order it online. Instead, I thought I’d call and ask them about the return. I’m not sure who I talked to there but she was very nice. She said I could return the rebuild kit and they would get the complete unit out to me right away. She put me on hold and checked to see if the unit was in stock. She came back with bad news. It was on indefinite back order. I told her I didn’t want to wait and would try to find one that was in stock. She did even better – she tapped into the dealer inventory system for all across the country and found the only two dealers that had one in stock! One was in Utah and the other was in Florida. Oh, and she said I could still return the rebuild kit.
I called the dealer in Utah first. While they showed it in stock, they couldn’t find the part on the shelf. Next I called the dealer in Florida and went through the same thing. Once again, they could not find the part on the shelf. Still on the phone with Florida, they said they would look in one more place. They came back to say that the unit was in the parts bin of one of their racers and since they didn’t think he needed the part immediately, they were happy to ship to me! Two days later it arrived in my mailbox!
HOW TO REPLACE A MASTER CYLINDER
With a can a carb cleaner, a can of brake cleaner, a new bottle of Dot 4 brake fluid and of course the new master cylinder I was ready to start.
Removal is simple. Mine has a protective cover so I removed the two bolts for that first. Next I removed the fluid line. Be careful that you don’t over twist the brake light sending unit that is at the top of the bolt. You can undo the connection if you need to. I didn’t and guess what? I need a new sender. 🙁
With the brake line loosened or removed I next removed the spring clip holding the rod to the brake lever. With that off, pull the pivot off.
Next remove the remaining brake cylinder bolts and that’s it.
Side by side of my old master cylinder and the new one
Installing the new unit.
I simply reversed the process. Because one of my bolts is also used to hold the shield in place, I installed the unit with both bolts temporarily. The shield will block the cover plate so you won’t be able to refill the fluid reservoir.
Installed, it looked like this.
The temporarily installed master cylinder so I can get to the reservoir
Next, fill the unit and then start bleeding the brake. Although I have a vacuum bleeder I use the old fashioned pump and bleed method.
A few minutes later I had a firm pedal. Next I removed the mounting bolts, added the protective shield, blue locktite on those and tightened everything back up.
MORAL OF THE STORY:
While Ronnie’s initially made a sale on me for the rebuild kit, when I needed a complete unit that they didn’t have… 1. They allowed the return to happen and more importantly 2. They went out of their way to find the part I needed with another vendor. That means a lot to me and I imagine it means a lot to you too. For service like that when I need a KTM Part I know who I’m calling first from now on. Thank you Ronnie’s!
Mileage: 24,751
Part Numbers
Rebuild Kit: 60013061000
Master Cylinder: 60013060200
He's an avid hockey fan, rides a mountain bike, sometimes rides a road bike, has a few motorcycles (he had a really fast one, had a big cool orange one, rode a really slow one, and is currently building a perfect "BDR Weapon"). If that isn't enough, he makes cheese and sourdough bread, loves strong beer and good red wine, and poorly plays the Mandolin.
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