Brake bleeding?

Hey all,

I just went to finally fire up my bike for the season been a little busy. Hoping to go for a ride / camping this upcoming weekend.

God news- Bike fired right up like a champ pushing 20,000 miles.

Bad news-Front brake is like a sponge. Tried adding some brake fluid and followed manual for brake bleeding from my drz400. Thing is the brake line doesn't seem to want to tighten up at all. Also when i open the bleeder valve and pull on the brake lever the fluid just kinda dribbles out. The only other time I have bleed lines on a car it was flowing. Wondering if anyone has any pointers. Hoping its something basic im getting wrong.

position the brake resivor so its top opening is level fill to almost to top full loosen bleeber a couple of turns, wait and watch if gravity drains the fluid, if so let it flow until the resivor gets low refill before its get to low and gets air in, tighten bleeder, leave lid off gently pump the lever, then bleed and bleed and bleed, if this doesnt work your gettind air in the system somewhere, if that desnt work calaps the piston in all the way than start bleeding again it will push the air out . it just takes a while longer than a car, or if you have a vacumn pump that would be faster. ive always gravity bleed all my machines and it works greet. good luck. oh almost forgot dont forget to put the resivor lid back on....

ok helpful i will give that a go after work tomorrow.

Along with the above good suggestions make sure your brake line is below the level of the line where it comes into the reservoir. If not the air will be trpped at the high spot in the line... everything from the caliper up has to be below the master cylinder reservoir for the air to escape.

Try filling the reservoir about 1/2 way then set the cover back on the reservoir. Pump up the brakes and hold the lever tight. Tap on the brake line from the bottom to the top with a screwdriver handle or piece of wood while holding pressure on the line. Push down on the line to make sure it is below the reservoir as you get to the top. Tapping the line while it is under pressure helps knock any small bubbles loose that can adhere to the inside of the brake line. Release the lever. Now remove the cover and watch the small ports at the bottom of the reservoir. Pull the brake lever inward a tiny bit slowly and look for bubbles coming up out of the ports. If you see bubbles make sure you hold the line below the level of the reservoir and move the lever a slight amount. Squeeze and release it just a small amount of travel each time. This opens and closes the return port and allows air to escape. Once the bubbles stop drifting up pump up the brakes hard again and do the whole process over until no air bubbles are present. It's a bit tedious but you will notice a big improvement in your brake feel if the problem you are having is actually air in your system. :smirk:

This can be very frustrating unless u make sure, as MxRob says, make sure the res is higher than anything else in the system. I had this problem with a set of Brembos on my KTM. The air was getting trapped in the arch of the brake line. I then filled the res to almost overflow and capped it, unbolted the brake assembly from the handle bar, raised it high and worked the lever. It tightened right up. Air bubbles rose up and up through the res:

Is this Brembo system? I thought maybe this link could be helpful then.

This is from Aprilia forum, and I just went though brakes bleeding nightmare with my Aprilia RSVR Factory street bike. I don't know if DRZ uses Brembo (my KTMs do, and parts are interchangeable), but the bleeding procedure and some tricks might be identical.

DR Z and DRs probably use a Nissin system but they work the same way.

Back in action! Thanks all. I think the culprit was the brake line running up higher than the master cylinder. Pushed a lot of air bubbles out during the bleed.

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