I installed front disc brake conversion this week on 71 charger. Did go until today, cant get end of rod to fasten into back of mc plunger. I bought a kit from Right Stuff. The orignal rod would not come out of old mc with force. Is this safe to keep this way. It seems it cant fall out after hooked to pedal. THANKS!

neoprene retainer on the end of the pushrod locks it into the piston securely & takes alof of force to remove it. A new retainer goes on the end of the pushrod rounded nub then installed into the piston till it locks into the wide groove around the ID circumference of the piston recess about halfway in. Check that the piston has the machined groove & if it is smooth tapered with no recess like a thimble then it is a power brake piston/mc & will not work with a manual brake pushrod as there ain't nothing to keep it locked in like it is with the old one you are trying to remove. If your floor jack has a center hole stick the mc/pushrod down in there then a horizontle rod under the jack thru the eyelet then pump it up to force it out

It really is essential that the brake rod be securely locked into the master cylinder. As Robert said, make sure that the master cylinder has a receiving groove in the hole where the pushrod goes. FWIW I've used master cylinders from both trucks/vans and from 5th.Ave's [ "M" bodies ] and most of them had power brakes and also had the necessary receiving groove. I use grease inside the master cylinder hole and a little on the rubber lockring. Put the lockring on the pushrod and shove it into the master cylinder. For an alternative removal method, remove the brake light switch from under the dash and pull up on the brake pedal. Watch your hands when it breaks loose as it will usually let go all at once. The factory lockring is best since it has a groove that allows the ring to compress and also lets air escape when the pushrod is installed, but an "O" ring or a short piece of vacuum hose can also be used.

Ok, thanks to both responces. I would say that I was not pushing hard enough for it to snap in place. I messed up by putting fluid in and bench bleeding mc before snapping rod in place. Thanks Dave

Got it fixed! As it turned out, the neoprene ring on end of new pedal rod was not thick enough to catch in recess grove. So I cut a piece of rubber hose that a tad thicker to put in groove. It worked fine. THANKS Dave