Master cylinder question????

[vl1500]

I converted over to vaccum brakes,new master cylinder,used booster from Advance Auto.When I am pumping my brakes to bleed the master cylinder(with the two hoses that comes with the master cylinder) I notice fluid shooting up inside the rear of the resivior only and the petal will not get hard...

 

[suicide six]

Getting the air out of these cars is mean unless a vac system is used.An extra set of hands,feet helps.

 

[zeus87gn]

If you still need the advice...

The pedal won't get hard until you hook up the lines to the wheel cylinders and then bleed them for air.

What you are doing is bench bleeding...getting the air out of the master cylinder before you go to the wheels. Makes for easier job at the wheels and will save a lot of time. Go slow with this and the air will be removed faster.

HTH

 

[dyermullet]

Is the fluid returning to the reservoir normal? or does that indicate a problem?

 

[zeus87gn]

Is the fluid returning to the reservoir normal? or does that indicate a problem?

Are you talking about a PM or a standard master cylinder on a vaccum system?

Sometimes a standard cylinder may have a small shoot into the bowl when the brake lines are connected. During bench bleeding this should not happen. If it does just move the pedal a little slower to minimize it and you shouldn't have a problem.

If you are talking about the Powermaster, fluid returning to the bowl should not happen when the motor is running. It is normal for fluid to return a little when you release the pedal from braking.

 

[dyermullet]

well the original post was about vacuum, and that is also what my fallowup question was about.

Since I made this post I read through this article posted elsewhere on the board.
Follow a Diagnostic Process When Curing a Low Brake Pedal, Bill Williams, Brake & Front End, June 2001
The article explains how the system works with the quick-take-up valve. Now I finally understand it. My factory service manuals for a couple of different vehicles just have one sentace describing the quick take up valve. No description on how it works or how to diagnoise it.

I think my quick-take-up valve has failed. I am going to try working on the car some tonight.