Brakes are sticking on my KZ750e

Depending on application, could try adjusting rear brake pedal to allow some slack before activating the push rod into master cylinder (where the push rod connects to and pushes against the master cylinder piston). The pushrod itself may be adjustable so as to allow some gap (clearance space) between its end and the master cylinder piston.

This is to assure the pads are not dragging against the disc while the brakes are not being applied. If dragging (akin to continuous light application of brakes while riding), excessive heat build-up may cause the brake to progressively bind more and more until it locks up.

Could wait until it completely cools off, then adjust (widen) the gap. If brake again heats up and begins toward locking, check the mentioned gap and may find it no longer exists, which means the gap was set too small, and should be adjusted even wider.

Would also change the fluid. Suck out most -- but not all -- old fluid from m/c reservoir. Fill with new fresh brake fluid. Bleed normally until most -- but not all -- reservoir fluid is pumped through system and out the bleeder hole. Again refill the reservoir.

Good Luck!

I am having a serious problem trying to get the master cylinder cover screws out. I have successfully stripped almost all remnants of the phillips head out, and that was attempting to use a "screw out" tool to try to remove them. Is there some trick that I don't know about because I don't have a repair manual yet? Has anyone else gone through this too? What did you do? What do you suggest???

use a small cold chisel and strike it an angle the head of the screw that is option 2 is to drill thru the head of the bolt with one size bigger drill bit and then remove the left over peices with vise grips.

timebomb33 wrote:

use a small cold chisel and strike it an angle the head of the screw that is option 2 is to drill thru the head of the bolt with one size bigger drill bit and then remove the left over peices with vise grips.

Good advise...Think I will go for option 2 since I have pretty much destroyed the head anyway. Maybe I can get a hex bolt that will fit to replace it...

Ok...was fiddling with the calipers again and came to the conclusion that one IS locked up. The other may be well on it's way to doing what the other is soon. What are my options here? Rebuild? Or is it gone and I need to replace now? Want to get the brakes working soon so I can enjoy my new ride!

Also a quick question:

When the brake lever is pulled, fluid runs through causing the pads to compress on the rotor. When I let go of the lever, the space between the pads should open back up on its own and fluid should return to the mc. Am I correct or will the turning rotors sort of push the pads away? I'm asking because the caliper that is not locked, will move back to the correct position, but only with some help from a screwdriver used as a pry-rod...

Just want to know if that one needs repair/replacement too!

Clutch, when you pull the lever, you push the fluid against the pads. When you release, the slight wobble of the rotor pushes the pads back and restore fluid level at the reservois. This should happen normally with not help. When I mangled the dust seals, after changing pads, I noticed resistance inmediatelly pushing the bike out of the garage. I knew had screwed up and needed new seals. Rinding confirmed my fears.

I have also stripped the screws on the MC cover. I went to the Home Depot, got me a stripped head extraction Kit,(in the bit section) and with a a drill in reverse, extracted the screw with no drama, following the instructions. There is no need to tighten these screws too much. I made that mistake once.

The word 'rebuild' on the calipers is a bit exagerated. Mainly is cleaning (tedious), and replacing seals. By your description, I don't think you have much of a choice. Like I said before, is not difficult, nor expensive, partwise. It is getting rid of the air later that was long a tedious for me. Makes no difference if it is one caliper or two.

So I'm guessing that to do the tear down, clean up and reseal, i need to first bleed the fluid out of the lines right? Or will it stay in the lines as long as the lever isn't pulled?

Drain all the fluid and I usually spray out the lines with brake cleaner and blow them out. When you get the caliper apart make sure to clean out the groove where the seal fits with a wire wheel on a dremmel. Everything will work great after that. I had the same problem on my bike when I went to Canada last year. It took me an extra couple of hours to get home because I had to keep stopping to pry the pads off the rotor.

Clutch, Please, get manuals and research a bit, before you start anything, so you'll know what to expect.

Mechanically, a hydraulic system is simple. The fluid makes it messy. Getting rid of the air; tedious.

However, there are some details that you should think about. For instance, how to get the pistons out of the caliper. You can push them with the fluid (very messy, they pop), or you can do it cleanly with compressed air.

Draining all the fluid is OK, as it should be replaced anyway. Nevertheless, be advised that the brake lever is an extremelly slow pump, like an hydraulic jack. It will take you very long to fill it back, unless you use a brake bleeding Vacuum pump ( ~ $40.00).

You could chose to keep most of the old fluid initially, by hanging the hoses higher than the MC, while working on the calipers. Getting rid of the air will get thru several bottles of fluid later anyway.

Google, brake caliper overhaul....order your seals and banjo bolt washers in advance.

M, some tips. as prev, related, the seals at brake caliper pistons are roughly square in cross secrion. they become "friendly" w/piston.and in typical use deform when brake is applied,allowing piston to travel enough for braking force, and withdraw piston when pressure falls. graft and destruction keeping piston from returning is one cause of brake drag. The master cyl is simply a Plunger which from mechanical means exerts the hydroic force when applied. and when released allows fluid to return to res.via a miniscule return passage. blockage here not only causes drag, but possible lock-up as temps rise. depending on models,caliper pistons can be removed without splitting calipers. and can be accompished more safely by stock hydrolic pressure than air. simply remove suspect frozen caliper from disc and pads and pump lever til piston escapes. examine caliper bore for scarring, piston for pits, remove seal and clean groove. an new seal is optimum and should replaced if any deterioration is discerned. calipers are usually located on carrior pins which allow centering at disc, now's a good time to clean and lube. hope this helps. G

hugo wrote:

Google, brake caliper overhaul....order your seals and banjo bolt washers in advance.

Did the Googling part already...will be ordering the seal repair kit from Z1Enterprises tonight....as far as the banjo bolt washers...are they not part of the kit offered by Z1 (doesn't look like it)???

meNmyKZ wrote:

Clutch, I just picked up mine the other day too. Looks same as yours but black. Did you check out the link on my other post. Someone is selling a service manual on CD for $8.99. I haven't gotten mine in the mail yet, so i can't say if its any good. Seemed pretty cheap though.

I think I'm going to go with the Clymers, but definitely let me know how the disk is. I plan on keeping this bike for a long time so if it's good, I'll get one of those too!