Hit a snag in hydroboost conversion

[Abomb]

So I have the new booster on and the master cylinder bolted to it, and I am trying to bleed the master cylinder on the car. I slowly step on the pedal and it will travel down and I see some fluid come out of the hoses, and then the pedal will not raise back up into original position. It just stays down by the floor and it will travel a little but never come back up. What gives here?

 

[Abomb]

Do I need to have the power steering hoses hooked up for the pedal to return up, I wouldn't think so.........I can't even pull the pedal back up by hand it feels like it's stuck on something on the way back up. The odd thing is I took the master cylinder off and the pedal came back up but I put the master back on and same thing happened it gets stuck down on the first bleed attempt.

 

[696]

Bad Master??? Nothing should keep the pedal from rising. The plunger of the master pushes back on the Hydro unit and the brake pedal SHOULD rise. Make sure the master cyl plunger is returning. Then look at the hydro to see if the rod or spring is bound up.

 

[TurboTnZ06]

Yeah it should come back up without you pulling on it. Also, I bled the master by drilling holes in the blue threaded plastic caps and ran some model airplane fuel line in them to a container to bleed the master by gravity before hooking up the brake lines.

 

[Abomb]

Thank you guys problem solved it was the master cylinder, must have got a bad one. I picked up a cardone unit and it works flawless.

 

[turbonut85]

Sometimes the new master cylinders come with the wrong snap ring in the rear. It has tabs that protrude into the bore and will catch on the piston on the booster, thus not allowing it to return. Happened to me.

The master bleeding procedure is explained here:
http://www.turbobuick.com/forums/how-tos/307690-powermaster-hydroboost-conversion.html

Good luck. ---Keith

 

[Abomb]

Turbonut now that you mention it that makes a lot of sense. The one that was causing me trouble has a snap ring like you described. That link you posted is what I've been following, good info there. Thanks