No Front Brakes

My front tire got clipped as I was passing someone on an asphalt section at the Elsinore GP today. I was doing fifth gear full throttle and the bike hit on the right side and slid a pretty good way down the pavement. Actually, further that I did. I was able to get up and everything checked out okay except for the front brakes: there weren’t any. There’s absolutely no pressure but there was plenty of fluid.

Any suggestions on where to look first? My initial thought is that a seal blew when the initial force was applied to the lever or as it was sliding with the brakes locked. I looked at the manual but nothing jumped out at me. I also thought air in the lines but it did have fluid.

I was able to finish the race and had a fun day overall. Shane Watts is EXTREMELY fast! I also now swear by my Asterisks since severe knee damage was probably inevitable…but that could be a different post.

If anyone’s right arm is 3/4 of an inch shorter than their left I’ve got a perfect set of ground down Renthal handlebars for you.

Troy

what pro's where out there ??? albe?? lampson? mike k.??

Kiedrowski didn’t make it but his bike did. I got a great picture of it in the pits. Rumor had it that Greg Albertyn was going to ride his bike. I’m not sure if Albertyn really did show up. If he did ride it wasn’t on Kiedrowski’s bike because it never left the Suzuki area. Lamson was there and somebody was tearing it up on a KLX 650. I think it might have been Healy. Although my blood is Blue, to be honest, KLM stole the show this weekend at Lake Elsinore.

I'm going to stick with the original question. Luckily, the hydraulic brakes are very straight forward and simple. You should be able to examine the system from the handlebar to the caliper. From the description, you have no lever pressure. So, start from the lever and examine the components at the handlebar. Check to make sure that the little adjustment screw/plunger isn't broken. Make sure that the fluid reservoir isn't cracked and leaking. Next, make your way down from the top of the hose starting at the banjo bolt at the reservoir. Look for a kinking caused by the crash. Often times, during a crash, there is an obvious abrasion where the worst damage is. Pay close attention to the brake line all the way down to the caliper. At the caliper, inspect closely the bottom banjo bolt connection. If you can't visually pinpoint the problem, you might ask a friend to pump the lever for you while you watch and LISTEN for leakage.

Take the lever off, take rubber boot off (the one behind the lever, covering the piston in the master cylinder). With small snapring pliers, take circlip holding the master cylinder out, and slide the piston assembly out. You will probably find that one of the rubber cups are damaged.

I'm wondering if it's possible that during the crash any air that may have been in the resovior didn't some how end up in the master cylinder. If there are no leaks then you may want to try bleeding it pretty good to see if you can get any air out. May not be the problem, but it should only take a few minutes so it may be worth a shot. Let us know what you find.

I think I'd also check the rotor. It could have gotten bent.

Merf

I followed Boit’s advice and started from the lever and worked my way down. Disassembling the Master Cylinder was easy. Once I got to the master cylinder piston (page 5-15 in my 01 manual) I noticed a small hole in the rubber cup closest to the spring. The rubber is pretty thin and probably blew from the force (pressure) applied to the system. I had to order the whole piston since Yamaha won’t let me buy the 50-cent rubber cup by itself. Nineteen dollars and an hour and it will be fixed. Thanks for all the help!

Troy

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