question ref installing new master cylinder

[taz7nads]

i have finished renewing all of the brake system, and am now to installing the new master cylinder. i bench bled as per the instruction, but noticed that the plunger/piston in the unit does not come back out as far as it did when empty. initially, it was at the outermost position, and I pushed it with the push rod to bleed it. now, it is farther up in the unit, and does not come all the way back out, and the push rod has to go up into the hole to make contact. is this correct?

 

[B RON CO]

Hi, if the piston in the master cylinder does not return to the flange on the back of the master cylinder there is something wrong. The piston is spring loaded and should always fully return. I can't imagine why you would have this problem. Can you contact the seller and exchange it? Good luck

 

[taz7nads]

ok, thanks. i'll swap it out for another, evidently this one isn't right

 

[Apogee]

ok, thanks. i'll swap it out for another, evidently this one isn't right

Good plan. As stated, the piston should always return to the snap ring when released. I'm not sure what method you used to bench bleed the unit, but I would suggest using the plugged port method, as it will not only bleed the unit of air, but also confirm that it will generate pressure and isn't bypassing fluid internally.