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K-Bike Brakes

V

vlad

Guest
Hello Friends, I have a 1988 K75s which has been totally complain free until now. The other day, after a nice ride, I drove it into my drive way and stopped, after letting the bike cool off I started to push it into the storage unit and to my amazement, the bike would not move. Looking in the calipers I notice the pads for the front two disks are jammed up against my disks. My idea is that the master cylinder has gone kaputz, any ideas. Ty for your thoughts.
 
vlad said:
Hello Friends, I have a 1988 K75s which has been totally complain free until now. The other day, after a nice ride, I drove it into my drive way and stopped, after letting the bike cool off I started to push it into the storage unit and to my amazement, the bike would not move. Looking in the calipers I notice the pads for the front two disks are jammed up against my disks. My idea is that the master cylinder has gone kaputz, any ideas. Ty for your thoughts.

There's a passage that allows fluid to return to the master cylinder. When bikes get older, that passage can get clogged, which keeps the brakes on. I'd try changing the fluid, but ultimately, you're probably going to need to rebuild your master cylinder.
 
Ty peeps,and thank you for your response. To be honest, it was not ridden hard at all, maybe two or 5 miles on a normal day(weather wise). I just parked it, and came out later to found that the brakes were locked up and I could not move it. The bike has been professionally maintained and I have had no problems with it. Well, time to suck it up and pay for that big towing bill. Once again, ty for your responses.
 
Brakes Locked

A temporary fix to get underway is to briefly back out the bleed nipple a tad with a rag handy to catch the seepage. That will release the pressure.
 
brake lines

If the temp fix Frank mentioned works for ya it's possible the brake lines have collapsed. I've seen this happen on cages but not on bikes so far.

An old volvo I worked on would lock the front discs after running in city traffic, when it cooled it could move again.

My old VW westfalia had it happen too, easy to tell 'cause it pulled to the side like crazy - age related I guess:dunno
 
Thanks for your suggestions. The bike has been sitting for about a month now, and he brakes are still locked up so I doubt temperature was a factor. I think I will use the bleeder nipple so that I can move the bike into a truck,and haul it off. Right now, it willnot move an inch. ty to all!
 
If they haven't released in a month it is possible that the caliper pistons are corroded and stuck. If the bleeder trick doesn't work you may have to push the pads back manually with a flat bladed screw driver being careful not to push too hard on the rotors.
 
Try new dust seals

I've had this happen.

I would start with new dust seals and clean out the calipers...this is a fairly easy job and I can usually do it within an hour....BUT getting the pistons to release the disk can be a 2 hour job.

If you're not that mechanical, it's probably worth taking it in for service.
 
k-brakes

I have had my 88 k75s for 4 years. I flushed the brakes 3 times, using a vacuum bleeder. This past winter when I tore the bike apart for winter maintenance I rebuilt the front calipers. I was surprised to find that even after bleeding the brakes yearly, I still had some water in the calipers that corroded them. The bleeder will remove air but not the moistuire that accumulated in the caliper volume. I ended up rebuilding the calipers as the corrosion caused the pistons to stick, luckily while it was stored for the winter. It's worthwhile maintenance and a good investment. :thumb

see ya out here
 
Re: k-brakes

abmwrider said:
I have had my 88 k75s for 4 years. I flushed the brakes 3 times, using a vacuum bleeder. This past winter when I tore the bike apart for winter maintenance I rebuilt the front calipers. I was surprised to find that even after bleeding the brakes yearly, I still had some water in the calipers that corroded them. The bleeder will remove air but not the moistuire that accumulated in the caliper volume. I ended up rebuilding the calipers as the corrosion caused the pistons to stick, luckily while it was stored for the winter. It's worthwhile maintenance and a good investment. :thumb

see ya out here
=========================

Ummm.... Water disolves in brake fluid. So flushing carries it out. That is why to use DOT fluids and not silicone brake fluid.

The bleeder will remove ALL FLUIDS whether gas or liquid.

This is not to say that if you let it go long enough corrosion will occur. Enough water in there and some oxygen, and it will corrode.

Corrosion is bad.

The real question here is why the system appears to have gone solid. Find that and the problem will go away.

The system has to be able to vent and volume change. It sounds like it can't.
 
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