Front Master Cylinder woe's

[Lbrown311]

So I took apart and cleaned my front master cylinder and there was a hole in the seal that goes in after the spring. I put it all back together and thought if it was a problem it would leak. Well now my plunger/piston wont return when I press the brake slowly. If I do it quick it will bounce back. Any ideas on the problem. Also... I pressed the brakes while the pads were off and the cylinder was stuck out. I used a c-clamp to push it back, but as soon as I tried to bleed the brakes (before I read about the plunger on the MC piston coming undone) the pads were stuck in. So now I have the pads stuck to the rotors, and the MC piston won't return to its open position after I press the brake. Fluid is going thru the lines as when I open the bleeder it comes out when I squeez the brake. Is the MC piston assembly just not lubed enough hence the sticking or is it a weak spring? Or something I haven't thought of *sighs* This is becoming quite the carb rebuild, new tires and brake pads quick fix LOL!!! HELP ME!!!!!
I know you will, but MAN DO I WANNA RIDE....safely tho

[3Phase]

Breathe ...

So I took apart and cleaned my front master cylinder and there was a hole in the seal that goes in after the spring.

The cup with the hole in the middle of it goes on the middle of the piston with the lip of the cup facing toward the spring.

The cup with no hole in the middle goes with its flat back against the end of the piston and the lip of the cup facing toward the spring. It should not have any holes in it.

I put it all back together and thought if it was a problem it would leak. Well now my plunger/piston wont return when I press the brake slowly. If I do it quick it will bounce back. Any ideas on the problem.

It's possible the master cylinder is not assembled correctly or you may have caught the lip of a cup on the cylinder wall, most likely the front cup under the spring folded back or twisted out of place when you assembled the master cylinder.

Also... I pressed the brakes while the pads were off and the cylinder was stuck out. I used a c-clamp to push it back, but as soon as I tried to bleed the brakes (before I read about the plunger on the MC piston coming undone) the pads were stuck in.

Using a c-clamp to push the caliper pistons back in the bore is fine but I have no idea what you're talking about when you say the the master cylinder piston can come undone.

The only way that can happen is if you forgot to put the retaining clip back in the end of the master cylinder after rebuilding it and you would probably notice that before you tried to add brake fluid to the system.

So now I have the pads stuck to the rotors, and the MC piston won't return to its open position after I press the brake.

Fluid is going thru the lines as when I open the bleeder it comes out when I squeez the brake.

I think you left something out there. You pushed the caliper pistons back into the bore with a c-clamp and now the pads are stuck to the rotors?

If the master cylinder piston is sticking then, yes, of course brake fluid will come out of the bleeder screw when you apply the brake and no, the brakes won't release while the piston is stuck.

None of it has anything to do with using a c-clamp to push the caliper pistons back into the cylinder or the master cylinder piston coming undone because if the master cylinder piston comes out the bore then the brakes won't work at all.

Is the MC piston assembly just not lubed enough hence the sticking or is it a weak spring? Or something I haven't thought of *sighs* This is becoming quite the carb rebuild, new tires and brake pads quick fix LOL!!! HELP ME!!!!!
I know you will, but MAN DO I WANNA RIDE....safely tho

Relax, take a break, go pick the lint off your dog or something then go back and pull the master cylinder apart to make sure the front cup isn't crooked or one of the cups folded.

Make sure everything is assembled correctly and try again but before you connect the brake line and fill it with fluid make sure the master cylinder piston does not stick.