Trouble with KZ front brakes

that sometimes helps,but after sitting for a couple years im guessing that fluid change to be a good starting point to get the old syrup out of there

kawboy13 wrote: When I redid my fr. brakes, kz1000 ltd 78, I found that popping the br. lever caused air bubbles to rise into the resv. They were tiny bubbles and I kept doing it until the brakes got the way they should be.

Hey 762Shooter,

I've experienced what kawboy13's talking about. Not sure about "popping" the lever but it seemed that as long as I was willing to slowly pull and release the lever I could continue to get these tiny bubbles coming back into the reservoir.

Part of the problem, I think, is that it's hard to get enough flow down the brake hoses to push the air bubbles down to the calipers. Have you tried removing the calipers and, with shims between the pads, bleeding the brakes while holding them up as high as the hoses will allow?

Good Luck

Bill

Throw the pads away. Rebuild the M/C and calipers. It's not worth crashing over a $100 worth of parts.


You are riding a 500+lb, 35 year old bike that had marginal brakes to begin with. Do it right and be safe.

Yeah, I'm going to go on the look for a set of pads now that I have a better idea what year stuff I'm working with. When I did the fork seals and cleaned up everything last summer finding pads was like finding hen's teeth and everyone was giving me prices from 150-250 bucks for a set of pads. That is why I opted to clean these ones.
If I don't have any luck getting better brake pressure I will get rebuilt parts and start over.

Z1 Enterprises has pads for those calipers, I bought some last year for my bike. They had a couple different grades of them from $25 and up. They probably have the rebuild kits too.

I will get new pads eventually but for now I give kawboy13 and KZCSI's ideas a try. After a short time I was able to get pretty good pressure at the lever, I slowly pulled in the lever and held it for a couple of seconds the released it real quick. I will probably try it again later to see if anymore bubbles come out.
Thanks guys.

Start bleeding your brakes at the master cylinder.

Pump it a few times and hold while you crack the line coming out of the master cylinder.

Pimp again and hold while you crack the line going into the splitter under the light.

Pump and bleed at every junction all the way to the calipers.

Replace parts as necessary.

The problem is, when you removed the calipers and re installed them, you pulled on the lever most likely all the way back to the grip. After many years of the seal inside only being moved a certain amount, you pushed it past that point and blew the seal out. The same thing happens in cars with aluminum master cylinders. That why whenever you do brake pads you just lightly pump the brake until pedal returns to normal, and not right down to the floor.

You need to rebuild your master cylinder and possibly hone out the cylinder bore. IDK, you have to inspect it.

The easiest way to bleed brakes is to first gravity bleed. With all the brake components installed, fill the reservoir and remove the bleeders. Keep the reservoir full as the fluid travels through the lines and out the bleeders on the calipers. When it's a steady drip, close the bleeders and refill the reservoir. At any point if the reservoir becomes empty you need to start from the beginning, so keep an eye on it. Now you can start to final bleed the system.

Open one bleeder, apply brake, close bleeder, let off brake, repeat. Using this method you will be contantly pushing fluid through the system, no need to pump, or remove the calipers or do the hokey pokey or whatever.

Those wheels could be '76 900 LTD. My '76 non-ltd has spokes and a drum rear. '77 900's had a disc rear I believe. Forks could be the same, hard to see in the picture though.

Go with Roy-b-boy-b's suggestion. I've gone this many times on bikes where guys have failed by trying to bleed only at the bleeders.

My solution was to simplify the whole setup with braided lines and a modern MC with a lever swith for the light. Works much better than the 1400 piece stock front brake setup.

Screw spending money on stuff you may not need. Try all your options with the parts you have before you go replacing them only to have the same result because you didn't go about it the right way in the first place.

76 900 ltd had rear disc brake on a mag wheel,i believe they were lestors

i gotta chim in on this because i just went through this on my bike you need to get a syphon tip for your compressor it bassially looks like a blow gun with a barb put a piece of line from your fully opened bleader to the tip and set your compressor to 90 psi hold the brake handle in and hold down the blowgun, make sure your masters full because its gonna suck out all the air and old fluid do this to both side and youll have you pedal back. I found this method out of desperation when i thought my master went bad because i couldnt get any firmness at all. If you need pics of the attachment let me know.