Brake problems

[audiviruz]

The never ending brake problems, I have rebuild my front calipers. But now I'm having problems with the brakes, the travel of the brake lever seem too much almost touching the handle bar. Before it just needed a inch before it would start to engage the brakes. I have read all the other threads about it and how to bleed the system and i have tried it all. I have run 3 bottles of brake fluid through the system and no change yet. I don't see any more air coming out. The only thing I can think of is that I need a Master cylinder rebuild kit. I check out the price on ebay and found one for $30.00 plus 15.50 shipping , does that sound right? How about a new master cylinder? or a upgrade? I don't mind paying more for an upgrade if it's better.

Any answer would be great.

[The CyberPoet]

(A) Odds are if you've changed the brake fluid & flushed it recently, based on the symptoms, there's still air in the system, especially if you didn't have the calipers apart and made sure there was zero water in them (water when hot turns to steam, steam back breaks down into air + water). The problem with the bleeder location is that it won't get water out of the bottom of the calipers unless you flip the caliper over while bleeding -- and if the bike sat too long without fresh brake fluid it may contain water (brake fluid will hold a certain percentage of water without settling; once past that point, it condenses out at the bottom of the system; hoses permit water transition over months of exposure which is why we change brake fluid).

(B) If you are using the stock cross-over tube on the fender (i.e. - brake hose goes from the master cylinder to the cross tube, then splits, with one tube running down to the right caliper, the other going from the cross tube to the left caliper), and you know there's no water, try this:
Park the bike on the side-stand, leave a rubber band over the brake lever for an hour or three, then remove the rubber band and leave it on the side-stand for a couple more hours without the rubber band. Because of the angle of the tube when on the center-stand, it doesn't tend to let air move naturally when trapped in the tube.

(C) Using SpeedBleeders? If not, get some (I do sell them). Makes errors in bleeding the brakes a non-issue.

(D) If for some reason, you used DOT 5 brake fluid, get it out. DOT 5 is silicone-based and does not have any provision for retaining any water content -- any water migration through the hoses immediately pools to the bottom.

(E) and finally, if you're getting a new master cylinder piston set-up, do yourself a favor, and order it new from the dealer, or get me to special-order it for you. Don't buy questionable stuff off eBay when it comes to your brakes.


Cheers
=-= The CyberPoet

[GytRDunKat]

Or get a newer braking system. I have a newer zx10rr master cylinder on mine. However, I did get it on ebay

[DumbLuck]

and i remember you tellin me you almost dumped the bike a couple times cuz the brakes were way way more grabby until you got used to the new setup.

Or get a newer braking system. I have a newer zx10rr master cylinder on mine. However, I did get it on ebay

[audiviruz]

Or get a newer braking system. I have a newer zx10rr master cylinder on mine. However, I did get it on ebay

What year did you use?

[scottynoface]

I would reccomend the 07-09 Nissin master from the ZX6R if you're wanting to upgrade the M/C (all the ZX10R guys upgrade to the entire 6R braking system for track and street )

[The CyberPoet]

There is a relational ratio between the master cylinder piston bore & stroke and the caliper piston surface area that needs to be generally maintained to keep your braking lever movements in the same force/travel range. Be sure that if you swap to another bike's system, whatever donor system you use, it has the same basic caliper piston area as the Kat (or only slightly less -- say up to 20% difference). You don't want a master cylinder piston from a bike with twice the piston area (or more in some cases, such as six-piston units)...

Using a system that's designed for twice the caliper piston area [e.g. - from a bike with four pistons per side on the front] will make the brake lever friction zone half as big as what you're used to and require only half the hand pressure at the lever to put the same force to the calipers (far too easy to lock the front wheel by accident).

Conversely, a master cylinder designed for a single-rotor front set-up that shares the same calipers your bike has would take twice the effort [or more] to use on the Kat (and could take twice the distance).

It's a very touchy subject (and prone with potential pitfalls if you don't do your homework in advance), and one that I don't recommend riders try willy-nilly. Master cylinder piston upgrades should also be at the very end of the brake upgrade list (behind better fluids, better lines, better pads, new seals).

Cheers
=-= The CyberPoet

[GytRDunKat]

and i remember you tellin me you almost dumped the bike a couple times cuz the brakes were way way more grabby until you got used to the new setup.

Yeah, I'm quite used to them now. But, if you recall, I was used to the squishy bad stock master cylinder. That and the stainless lines/pads/rebuild. Once I put the new one it went from Pinto braking to F1 braking.

What year did you use?

04 iirc. At the time I was replacing my master cylinder, the repair kits for the stock unit were more expensive than the route I went, and Black_Peter helped me find the one I have. Quite frankly, I got lucky on ebay.

Master cylinder piston upgrades should also be at the very end of the brake upgrade list (behind better fluids, better lines, better pads, new seals).

Cheers
=-= The CyberPoet

That's how I ended up with a new one. I chased everything down, and replaced everything. Then I brought it up to BP because I was just done dealing with it, and he said the mc was shot. I thought it was air in the lines, and went through about 300 gallons (ok, so that's exaggerating a bit) and it still felt mushy. It's all good now.

Oh, and speed bleeders made this whole process a bunch easier, and I only ended up with a few tools lodged in the drywall, vs my whole toolbox Initially BP thought it was the speed bleeders (not being able to back bleed) that were causing the issue, but once I ran through it enough (and reading every thread that says "bleed" on it here), they worked fine.

[The CyberPoet]

That's how I ended up with a new one. I chased everything down, and replaced everything.

Note that I said upgrades. Repair/replacement is a different story -- when it needs it, it needs it

Oh, and speed bleeders made this whole process a bunch easier, and I only ended up with a few tools lodged in the drywall, vs my whole toolbox Initially BP thought it was the speed bleeders (not being able to back bleed) that were causing the issue, but once I ran through it enough (and reading every thread that says "bleed" on it here), they worked fine.

I rarely see any issues with SpeedBleeders, and always it's the same three things when I do see an issue:
(A) The user uses gorilla force on installing them and snaps 'em off in the caliper (it's like 6 ft-lbs, or single-finger-lightly-tight, guys!), or
(B) They fail to read the bit about rotating only 90 degrees to open the one-way valve (and rotate 180+ degrees, letting air in), or
(C) After a certain number of cycles, the gummy stuff on the bleeder screws gets worn away and they don't want to seal as well when rotated that 90 degrees to open (esp. if over-torqued previously). The sealant is available as a separate item (to brush-on), but typically it takes over 5 years of bleeding brakes annually to reach that failure point (racers who bleed before every track run tend to hit it sooner).

Cheers
=-= The CyberPoet

[BrianT]

My post 600 has a very slow brake fluid leak, so I planned to replace the caliper seals and install stainless lines & speed bleeders. I figure doing so should stiffen up the brakes slightly, too. Any other suggestions in the low-dollar fixes?

[The CyberPoet]

My post 600 has a very slow brake fluid leak, so I planned to replace the caliper seals and install stainless lines & speed bleeders. I figure doing so should stiffen up the brakes slightly, too. Any other suggestions in the low-dollar fixes?

Where's the leak coming from? My best guess will be that it's just a crush washer that needs to be replaced (typical).

As for your question: IMHO - EBC "HH" grade pads if you want serious stopping power...

Cheers
=-= The CyberPoet

[BrianT]

Where's the leak coming from? My best guess will be that it's just a crush washer that needs to be replaced (typical).

=-= The CyberPoet

I looked the entire brake system over, but couldn't find a leak. I just noticed the reservoir is low. I take it the crush washers you referred to are used where the lines connect to each other, the reservoir and the calipers?

The bike has 20,800 miles. Is there a recommended interval for replacing the piston seals? Maybe it's an unnecessary repair?

[The CyberPoet]

Factory manual called-for interval for the piston seals is as follows:
(A) Whenever the caliper pistons will be forced backwards in their travel;
(B) Whenever you replace the pads (since at that time, you have to force the pistons backwards).

Fluid flush is called for every 2nd year at *minimum* (every year in high-humidity environments), hoses replaced every 4th.

Cheers
=-= The CyberPoet

[ICEG]

just get new ones from ebay

[BrianT]

just get new ones from ebay

Entirely new calipers?