New Master Cylinder Leaking Again!!!!

[2fine69s]

Hey guys,
I have a really bad problem again!. I have bought 2 NEW (not remanufactured) master cylinders from Car Quest and both are leaking from the rear reservoir. So I need your help to let me know if Im doing something wrong. Her goes... I bench blead both. After, I let them set while I was getting my stuff ready to put it on the car. When I go back to get it, half the fluid has leaked from the rear reservoir brake line fitting hole. My thing is, if its leaking now I don't think its going to stop itself later, and when I apply the brakes the pressure will bypass the plunger seal cup. Am I correct, I need your input...
Thanks
Martin

 

[67Dart273]

You're telling me it's leaking from a DISCONNECTED and OPEN fitting?

Of course it will

 

[2fine69s]

That correct, but if its leaking now, whats to stop it from leaking past the cup when you apply the brakes?

 

[2fine69s]

OK guys,
After talking to several of you about this, it appears that it is normal. I just didn't want to hit the brakes and the pedal go to the floor. Thanks for all your help,
Martin

 

[BillGrissom]

Normal for fluid to flow freely out of an open port. Indeed, many people "gravity bleed" their brakes by connecting tubes, opening a wheel cylinder and letting it run out slowly as they add fluid to the reservoir. You still need to "bench bleed" the MC alone by pumping the rod, then quickly connect the tubes. And quickly clean any spills off paint, unless using silicone, in which case you won't want to waste a single drop anyway.