Hubster, I have a bit of a problem with the front brake lever on my ZX-14. I have the lever reach adjustment set to 1 (maximum span) and the lever comes almost back to the grip before I get any brake action, see photo below.

I recently changed the brake pads, brake fluid and bled the brake system. The lever is not spongy like there is air trapped in the system, it just comes way back before it suddenly gets firm, like there is nothing, nothing and then suddenly a firm lever.

What sayest thou, Sir Hubster?

* Last updated by: Kruz on 8/10/2023 @ 8:51 PM *

I'm not Hub, obviously. I say bad bleed. Depending on if you let your reservoir empty you may need to bleed your master cylinder, then at your calipers.

If you have ridden the bike, vs say rolling it, how strong is the braking once you've hit the point of resistance? If you have extremely strong braking, like the wheel locks up, it might be the pads needing seated or something else than bad bleed.

If you just installed pads and did all this work, the first thing should be to pump down to seat the pads. If you've done that then it's definitely air in the system.

My suggestion is use a vacuum bleeder, IME they are simpler and result in a more reliable bleed vs pump n purge. And if you used one, it's possible you didn't use it correctly. Sometimes this happens, I have had to re-bleed before especially the first few times .

You probably have a LOT of air, which is why you're not getting the spongy feel which is when you might have a few bubbles in your system.

Kruz, Like Vic said, it's got air in the line and/or master.

The video should show it's not some sort of open and close at every stroke, but the constant pumping of the pedal/lever with an open nipple. When I installed the hose to the caliper, bled it once, I had a hard pedal. Being it was a ground up chopper with that style master, I didn't know what it felt like. The second op/cl made no difference. Where I went to the master and broke the banjo open, that was more and exercise to bleed both ends just to make sure if not hard; one could get a pedal at the master.

So bottom line, I had a pedal with one op/cl and should have stopped there. I get a chuckle of the might-vac's and the titty pumps to break out and attempt what is just too easy, being the secret is to just keep pumping till you have arm pump in the arm.

For your situation, Kruz, I'd try a break at the master's banjo, or if it has a nipple at the master (radial style), that guy. Open, pull lever and close before the lever hits the grip. Pump it up so the air out is liquid in and there is your harder lever.

Say no joy. Then it's clear hose, run it so there is a high loop off the nipple at the caliper. High loop is for when you stop pumping, the clear line has so much fluid above, it sucks in fluid, not air. Short loop would suck more fluid out of the line as it drains, thus air going in the caliper. Start with the farthest caliper from the master.

The whole point of the higher loop is to walkaway, refill the master not needing to close the nipple. Hell, go have lunch and come back. That's the difference between pit crash work, or a few more laps lost hooking up the titty tools. No offence.

Wow, vacuum bleeder is multiples easier than that. Especially when it comes to autos.

One of the most significant advantages to using a vacuum pump is removing all the old fluid in the reservoir. Just suck it out, for a complete full flush instead of having to pump through old shrek piss.

Mine did the same thing. You have to bleed the master cylinder it has a bleeder on the reservoir

I'm not Hub either but here's how I have bled and it worked every time even after completely draining the fluid from the MC and installing brand new lines.

http://zx14ninjaforum.com/messages.cfm?threadid=EF69194F-1372-66AE-3B981C05AA26103E

I can see how the stock three line system could trap air in the line that arches over the fender. I have never heard that to be a problem though.

Bleed until you see no air gaps in the drain tube. You're always going to see tiny bubbles from the air that gets sucked in past the bleeder valve threads but that's just going straight out down the drain tube.

As for the tity vac, I bought the top of the line and it didn't produce enough vacuum to bleed. The cap on the cup that catches the fluid has holes in it to lock the cap on but the holes also reduce the vacuum I believe. Maybe I got a bad one. I'd pick one up at O'Reilly's so you can bring it back if it doesn't work. If you do this the old fashioned way, no need to crank on the bleeder when you close it, just barely snug so you don't stretch the threads. That will close the valve enough to prevent air from getting sucked in while you pump the lever. Torque the valve when you're done and expect some minor seepage for a while, wipe and flush with water every day.

Rook you got a bad one or had other issues. Mine is at least 10 years old if not older.

Using a vacuum bleeder
- vacuum the reservoir
- add new fluid to the reservoir
- attach vacuum line to bleeder valve
- add a little vacuum (-3 yo -5)
- break bleeder open until fluid starts being pulled through
- monitor
-- reservoir to ensure it doesn't empty
-- keep a small vacuum
-- drain line to see when fluid is clear
- tighten bleeder once new fluid is visible

As I've used the tool more and more the simpler and more straightforward the process has become. I also have build my own drain reservoir which is especially helpful when flushing and bleeding autos. About any old throw away bottle will do, like an 64 oz Pace salsa bottle. Drill a couple holes, and you can flush any line without having to stop and empty the reservoir like with included 8 oz drain reservoir.

To me this could've be any simpler.

Get a "pneumatic air bleeder" for like $35.00

Uses a air line and no pumping. Completely flush brake fluid every 12-18 months
Only takes a few minutes.

Can't even imagine doing it the old way.

Mityvac is ok if you don't have air. Went through a few of the mityvacs
before switching to the pneumatic air type.

Rook you got a bad one or had other issues. Mine is at least 10 years old if not older.

The key might be NOT using the reservoir included with the tool. You said you're using a home made bottle and that might be why yours works?? IDK. Never heard a lot of complaints on this tool but it sucks if you have to make your own catch bottle to replace the one they designed which can't hold enough vacuum to bleed brakes. The thing cost $80 and that was also 10 years ago.

Completely flush brake fluid every 12-18 months
Only takes a few minutes.

Didn't we go through this last year? Your bellows in the reservoir were expanded from low fluid. Take the cap off and check that out.

This is very common on bike sites. The big boy's book, 'Chapter-15-Brakes,' shows on the special tool page; no tit-tea drinking fountain hose me suck tool, or the might-tea-vac to bleed the system. Says to use a clear hose and container. Lever/pedal action is the pump.

Signed,
Have DOT-4-Bubbles Will Travel

Well Hub now that you mention that, bleeding the old fashioned way ensures the MC is working properly.

Rook, it's more a qualifying test for pit work. There is no art to it. It's just too simple bleeding brakes. Bubbles could just roll while the fluid passes. That's when you have to remove the component, hold the slave or master up so the bubble rise and leave the master/slave.

That one's for you Kruz, where the ape site had a soft rear pedal after bleeding. The foot master had to be removed to free the bubble. Trying to remember if I had to remove mine for that same reason?

Hubster, as usual your analysis is spot on...

Thank you to the other folks who took time to contribute to the discussion. I learned/remebered some things.

It's funny Hub is quoting the service manual to me. I'm pretty sure a few years ago he flamed me for telling people to follow the service manual.

Can't take a thing away from Hub but his diagnosis referred to you as well. You nailed it, bleed the mofo. If that doesn't work, there's something wrong with the MC. I might add, follow my procedure to the letter. If that doesn't work, I would suspect the rubber parts of the system need to be replaced. For that money, I'd go aftermarket. I planned a set of ISRs front and rear, calipers and MCs.

Another vid using nothing but inducing 'arm pump in the first moto.'

https://www.youtube.com/v/AiCGcsv-aL0

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