Brake Bleeding Issue - KZ650

[fury413rb]

I put a modern Nissin master clyinder and new braided lines on my bike. After nearly 6 hours of attempting to bleed them I am giving up. I feel like an idiot - Ive never had this much trouble.

The bike is still in the standard configuration with the single line to the splitter and a line to each caliper.

Started out bleeding the master by hand with a line cut and looped into the reservoir. After I got consistent flow and lever resistance if I pinched the line - I bolted the line to the splitter on.

I opened each bleeder and left them open and after about 20 minutes I had fluid coming out of both bleeders. After about an hour of conventional bleeding I started to go insane. Absolutely no lever resistance. I had probably put more than a quart through the system with not much air coming out of the bleeders into the bleeder reservoir thing.

The splitter looks like the perfect place to trap air so I removed the entire system intact - clamped the master to a high shelf, the splitter to the shelf below it and stuck the calipers below that. Put pieces of wood in the calipers to keep the pistons from coming out. Same thing - about a quart through it (at this point I am recycling the fluid because I have no optimism) and absolutely no improvement. I crack the banjo at the master - getting tons off fluid there - crack the banjos on each end of the splitter and the calipers - all fluid ( man Im glad I painted all this shit....)


I put it all back on the bike and then tried reverse bleeding - injecting fluid into the bleeder screw using a syringe I found in the kitchen - probably from the girlfriend on thanksgiving for injecting turkey - not any more!

After I filled the master reservoir by injecting fluid at each caliper - I got nothing. Tried bleeding the normal way - tons of fluid - no resistance at the lever.


I left it sit over night with the cap off and the bars turned to the left so the master is at the highest point. I have read people clamp the lever back to the bar over night but that would close off the ports in the master so I am not sure why you would clamp the lever? Am I missing something?

I feel like an idiot. All I managed to do is get brake fluid all over some fresh paint, spill some beer and kill a perfect day.

 

[HerrDeacon]

Sounds like you may be going about it the wrong way. Even on a completely dry system it shouldn't take that long. If you're going and going and seeing no difference its time to step back and take a look.

How are you actually bleeding them, do you squeeze the brake lever, keep it squeezed, open up one bleed screw, close screw, release brake lever? Also, I usually have a tube on the brake bleed screw that goes into a catch can with the end submerged in brake fluid, helps to keep air from being sucked back in the system. If this is what you're doing there is probably a tiny bit of air hidden in there somewhere. I know some of the KZ guys remove both calipers from the bike and suspend them higher than the master. I've never had to do this but it worked for them.

Also, not a good idea to leave the cap off all night since brake fluid absorbs moisture.

 

[fury413rb]

I know the fluid absorbs moisture - I figured once I could actually get some improvement I would flush all of it with a new unopened bottle. Should be easy once its functional and I am tired of wasting good fluid so I have been recycling it. Once there is some actual brake function off the of fluid will be replaced again.


I agree - thats why I posted this since I am pretty frustrated. At first I was just "gravity bleeding" with the bleeders open till I got fluid at the bleeders. I have each bleeder screw hooked into a hose and a little bottle - just like you mentioned. Bought two of them from Harbor Freight.

I was doing - open bleeder, depress lever, close bleeder, release lever. I usually start that way till I get some resistance and then I - depress lever, open bleeder, closer bleeder, release lever.

I didnt think about having the calipers higher - I was always putting them lower than the master. I can take them off the bike again and try that.

 

[fury413rb]

I hate the damn V-Splitter too. Just looking at it and you can tell it would trap air like it was its job.

 

[fury413rb]

I hate the setup. It seems perfect to trap air everywhere.

 

[irk miller]

I had the same issue with my CB. For me it was the o-ring in the cap. My cap has a vinyl ring with a lip that was upside down, so when I tightened on the cap is flexed the ring producing an air leak. If you're drawing air, it should make a squishy sound and cause the fluid to foam a bit.

 

[2_DONE_THE_TON]

i had the same problem with my ducati monster and my kawa.

checked the system for leaks and/or clogging,nothing.

then i bought me a vacuum tool to suck the fluid trough the system.
it works perfectly,but only if you pump steadily with the lever while you are using the vacuum pump.

paid 60 euros for that thing and it paid off.

 

[fury413rb]

put the rubber lines on - pinched them with vice grips. Got a rock hard lever after bleeding at the banjo on the splitter. replaced one caliper at a time and bleed at the the splitter to master banjo and at the calipers.

I got a good lever with one caliper and once I added the second I got a spongy lever. I don't seem to be getting any air out of the splitter now, absolutely no air out of the calipers. I then tried vacuum bleeding out of the calipers for about another pint of fluid and didnt get any air.

Called it a night and gave up. I have it now with the lever cable tied back to the lever as nearly everything I have read or had people tell me "this works"

Let it sit overnight and today while at work.