rear brake pedal locked up

[MyChopAintSlop]

i got an 1980 GS750L, i just got it as some of you already know. i went to go press the brake pedal for the rear brakes and it didn't budge. I took the pedal itself off, so now it's just the stubby sprocket looking thing that goes through the frame. is this supposed to move? it seems like it would have to, correct? what do i do about getting this to free up and move again?

[chef1366]

The spindle looking thing acts as a lever that pushes up the piston in your rear master cylinder.Yes, it should move. I have the same bike(just bigger motor) and mine is quite loose when I remove the foot lever. Either it sat outside for a LONG time or someone laid it down and bent the piece. Remove the foot lever and see if you can tap it out. I see these all the time on Fleabay.

[brveagle]

Your pump is locked up.. It's bolted to the frame and is controlled by the foot lever.. Take it apart and see if it's salvageable.. If not, get one off ebay

[Road_Clam]

i got an 1980 GS750L, i just got it as some of you already know. i went to go press the brake pedal for the rear brakes and it didn't budge. I took the pedal itself off, so now it's just the stubby sprocket looking thing that goes through the frame. is this supposed to move? it seems like it would have to, correct? what do i do about getting this to free up and move again?

It's either the brake pedal pivot thats siezed, or the actuall internal m/c piston thats siezed. If I was to guess, I would say the piston. 22+ year old GS's inherantly will have the internal brake fluid mix with moisture, which causes corrosion, and all kinds of braking headaches (mainly sticking brakes)

[chef1366]

Looking back(hindsight is 20/20) I'd have to agree that it is the piston in the master cylinder.

[zeroaffinity]

I have an '80 850G and I had the same problem when I first got the bike. It had been sitting outside for god only knows how long and the rear brake didn't work. My experience was a little different because I could press the pedal - the rear brake still didn't work though. It was the master cylinder. The rod was actually pushing through the piston, if you can believe that. So I overhauled my master and all was right with the world. Sounds like seized or broken rear masters aren't terribly uncommon on these bikes.