Master cylinder rebuild?

[Krooozn]

Can anyone tell me how hard it would be ro rebuild a master cylinder on a 1981 GS450/L? Mine needs to either be rebuilt or replaced....the plunger thing is stuck in the "in" position and I can't get it to move....so therefore when you apply pressure to the handle to engage the front brake, the handle just kind of flops around....with no restriction and the caliper doesn't engage....

Thanx...Anita

[rkubik]

Overall not very hard to do if you want to stay true to vintage, but does take lots of time. Get a newer single-disc one from eBay.

[Steve]

It's not that hard, but it sounds like you may have a difficult time getting the piston out of your cylinder first.

When you get it out, you will have to clean the bore so it won't tear up the new seal that comes in the rebuild kit.

.

[tkent02]

You can hook the master cylinder up where the rear caliper is, use the banjo bolt to connect it. Step on the rear brake to force the piston out of the master cylinder. There is a circlip in there to be removed first.

[Nessism]

Before ordering a master cylinder rebuild kit I suggest you remove the piston from the master and inspect the bore surface of the aluminum for corrosion pitting (use a flashlight or strong light of some sort). If the master is pitted, it's junk and can not be rebuilt.

Good luck

[coolksprt]

It really wasn't all that hard. It was one of the first things I did on my own when I started to go through preventive maintence. If in doubt, post a pic and we'll see what's going on! Brakes aren't something to second guess about.

The bore should look something like this.