Author Topic: NO REAR BRAKES AHHHHH!!!!! (Read 5645 times)

Pylar · « **on:** April 24, 2007, 07:25:55 PM »

Hey folks,

I've been a lurker on BA for about a year since I got my bike. Been a real fan, and you guys have helped me out by reading previous posts. Anyway I have an issue with my rear brakes.

The pedal is going all the way down and I feel no resistance. When I leaned down to look at the caliper and pressed the pedal, I did not see any movement from the caliper. The rear rotor is a mess, and I've already ordered a new rotor and rear pads. But I am hoping I don't have to replace/rebuild the caliper. So my question is do you know why the pedal would go to the floor? Also if I have to rebuild the caliper is there a reliable rebuild kit out there or do I have to replace it? I have at 1999 Bandit 1200 with about 28000 miles. The calipers are OE.

Thanks!

ZenMan · « **Reply #1 on:** April 24, 2007, 07:28:06 PM »

Sounds like a blown master cylinder. Unless the linkage came apart.

Do you have any brake fluid leaking anywhere?

Pylar · « **Reply #2 on:** April 24, 2007, 07:32:37 PM »

No fluid anywhere, and the brake fluid is to the full line. The front brakes are very responsive. So I thought that would rule out the master cylinder

ZenMan · « **Reply #3 on:** April 24, 2007, 07:47:29 PM »

Your front brakes have their own seperate master cylinder... it's on the right handlebar, the little square reservoir that your front brake lever is attached to. Should have a sightglass for checking your fluid level.

The rear brake master cylinder is probably located on the frame under the side cover. Your rear brake lever is attached to it with a linkage. Follow the linkage and you'll find the master cylinder.

If the linkage is properly attached, check the fluid in the reservoir. If it's low or empty, that's your problem. But that also means you probably have a leak somewhere.

If it's low, fill it up and pump your brake lever. If it pumps up, then you found part of the problem. You still probably have a leak somewhere though.

If you fill it and it doesn't pump up at all, then your master cylinder is blown and you'll have to rebuild it.

It sounds as if your brakes have been neglected for a long time. If I were you, I'd go ahead and rebuild both master cylinders and maybe even the calipers front and rear. Kits are available at your dealer, they're not very expensive. Labor is though, and you can save a lot doing it yourself.

Pylar · « **Reply #4 on:** April 24, 2007, 07:50:13 PM »

Thanks Zenman, I will take a look at that when I tear down the bike to replace the rotor. Thanks for the info.

ZenMan · « **Reply #5 on:** April 24, 2007, 11:19:22 PM »

Anytime, glad I could help.

Keep us posted on your progress, if I don't know the answer then somebody here sure will.

My experience is limited to motorcycles in general, and all-around mechanical stuff. There's a lot of folks on here that know a helluva lot more than I do when it comes to Bandits specifically. But I try to contribute when I can.

pmackie · « **Reply #6 on:** April 25, 2007, 03:19:31 PM »

Hey Pylar. No resistance at the lever means no (or not enough) fluid flowing through the rear brake line. As ZEN said, maybe a master cylinder, or leak.

Check a few things...
1. Fluid level in rear reservoir. Should be on the right side, above the rear pedal. Follow the pedal linkage to the rear master cylinder. The reservoir connects to the master cylinder with a hose. If it's empty, or low, you need to refill it.

2. Whether the fluids low or not, bleed the rear brakes. They likely have air in the lines. There is a bleeder screw on the rear caliper. You should put a hose over this screw so the brake fluid does not squirt everywhere.

Basic process is to pump the brake pedal (to force fluid into the line) and hold it "ON". (You may find it helpful to have a friend). Then crack open the bleeder screw and let the fluid drain, and close the bleeder. Keep repeating, while refilling the reservoir, until you see clean fluid, and NO air bubbles coming out the bleeder screw. Likely there are 2 bleeder screws, one for each piston on the caliper. Once clean fluid is coming out both bleeders, you are done.

3. NOW check for leaks. Have someone hold down the pedal. It should be firm and not move. While putting pressure on the system, look for leaks. Reservoir to master cylinder, cylinder to hose connections, hose to rear caliper, etc.

4. If you have no leaks, and the pedal still moves, you have a bad master cylinder. (fluid is bypassing the piston in the master cylinder.)

Hope this helps.

CWO4GUNNER · « **Reply #7 on:** April 25, 2007, 03:54:00 PM »

Pylar · « **Reply #8 on:** May 01, 2007, 06:43:09 PM »

Hey guys, just wanted to follow up on what happened. I ended up replacing my rear brake rotor, and pads. The original pads were worn almost to through to the shim (I know that is no way to maintain a bike). Once I replaced the parts I was able to bleed the brakes and the everything worked fine. I ended up riding a couple hours north to attend a big bike show in Leesburg, Florida that weekend and the bike ran like a charm. Thanks for your help!!

ZenMan · « **Reply #9 on:** May 01, 2007, 08:21:04 PM »

Sounds like you had a lot of clearance, and the pistons ran out of travel... plus having air in the system that you were able to bleed out. I hope you bled enough fluid to replace all the old stuff...

Glad it was a simple fix!