You might be just like me, one of the KLR owners out there and therefore are probably having issues with your KLR braking system as well.
On the front braking system, I had salt water get in and the pistons corroded so much that they literally locked in. On the rear brake system, from pretty much the start or around 10 000km, when going downhill for a long time, the system would heat up, expand and lock itself. The result, no rear brake going downhill on really steep hills. Your only option left is to either stop and wait for the system to cool off or use the engine brake in 1st along with the front brakes and that can be a bit tricky. These days, my front brake stays engaged if I leave the bike over night sometimes but usually comes back to normal after riding for a bit.
So here is how you can try to solve the problem. I am no mechanic so maybe there are better solutions out there.
Take the system off
Take the 2 pins holding the pads out
Check your pads. Mine are totally worn out. They are a bit worn sideways too, meaning that the rear wheel wasn’t totally straight or that the pistons or the holding bracket wasn´t sliding properly.
Now look at the horror on your pistons. With some pliers and a piece of cloth, pull them out if you don´t have any compressed air handy. If you have compressed air, you can blow the pistons out with that. Use the cloth between the piston and the pliers so that you don’t mess up the piston. Just literally pull the pistons out. Chances are that you might have a hard time, so twist them around a bit. If they are totally stuck, use whatever you have to get them unstuck.
Look at those rusty kawi pistons. Not really made for salty water.
Get the seals out with a sharp tool. Careful so that you don’t damage the seals. Also, before leaving on your trip, buy a set of pistons and seals maybe?
Clean the seals, all the crap and corrosion out of where the seals go. I used a piece of cloth with a screw driver bit to get in there.
Clean the remainder with a tooth brush.
Clean the pistons and try to get the rust off. Good luck with that. I tried gasoline, oil, and anything else I could find. The rust is stuck there pretty well. I used the pliers to grind it off and then a cloth to get the small stuff off. You wont get everything off though cause the rust gets into the piston and eats well into the metal. Just do your best I guess. I think that maybe some really really fine sanding paper might help, but no idea on that. Let me know on the best solution you might find.
Once everything is clean, reassemble the system. You will notice how easy the pistons go in and out now.
You will now need to bleed the system. Push down on the brake pedal a couple of times to build pressure. Keep it in the pushed down position then open and close the bleeder valve. Do not release the brake pedal till the valve isn’t closed. Keep doing this till you see lots of brake fluid spilling out the valve every time you open it up. You will also start feeling more pressure on the brake pedal. Don’t forget to keep topping off your brake fluid. If you forget, you’ll get air in there.
All this helped with the rear brake system, but when it gets REALLY hot, it still locks up and wont work. It’s surely better than before. I will soon change the front pads again and will clean the front system all over once more. Gonna try to find some fine sanding paper first.
Good luck and let me know if you have any other suggestions on the above. I know how to do this because Josh showed me on the front system in Colombia when it locked up right after getting it off the boat. Thanks Josh! I’m no mechanic so do it at your own risk. I know that there’s a couple of good mechanics sometimes reading my posts so maybe comments? Looking your way Csabi… 😉
Calgary to Brazil on a KLR 650... 