No brakes after WJ booster/master cylinder.

[cal]

It sounds like a bad master cylinder to me. :/

 

[xjbubba]

So I'm still having problems with this. ---- What would cause this? Also, when I bleed it, the back two usually go pretty well but when I get to the front passenger side the first or second time I open the bleed valve generally results with the pedal going to the floor for the person inside even though it was hard before. I keep bleeding and the pedal usually doesn't get better during the bleeding process (with the bleed valve(s) open) but after I close them it gets hard again.
I know that my booster is leaking pretty badly as it hisses almost all the time, and it's LOUD. But from my understanding this should make the pedal harder, not softer.

The way you describe your issue, and the action you've taken, considering the advice given you, I have to believe your understanding of hydraulic brake systems is "wanting". With that in mine, I would strongly recommend you either take the Jeep to a professional, or obtain a book explaining the basics of hydraulic brake systems. An example would be Haynes Automotive Brake Manual.
I don't write this to be cruel, but you need some basic understanding of both theory and real-world application in order to make use of the advice given you here.
In all likelihood, your brakes have not been properly bleed.

 

[jeeperjohn]

When you bleed the brakes, have the helper pump up the brakes then hold pressure on the pedal. Open the bleed valve and let the fluid come out. Make sure your helper keeps pressure on the pedal until you close the valve. Now close the valve and have the helper pump up the pedal again. If the helper lets up on the pedal while the bleed valve is open it will suck air back into the system and you will get nowhere. You have to open and close the bleed valve every time your helper pumps up the brakes.

 

[northwestxj]

The way you describe your issue, and the action you've taken, considering the advice given you, I have to believe your understanding of hydraulic brake systems is "wanting". With that in mine, I would strongly recommend you either take the Jeep to a professional, or obtain a book explaining the basics of hydraulic brake systems. An example would be Haynes Automotive Brake Manual.
I don't write this to be cruel, but you need some basic understanding of both theory and real-world application in order to make use of the advice given you here.
In all likelihood, your brakes have not been properly bleed.

I find this to be very very humorous. I know EXACTLY how to bleed the brakes, it's not that hard. My brakes have been bleed numerous times, and I assure you they were bled the correct way. Let me go over it, step by step:

First, start at passenger rear. Person inside Jeep pushes pedal as I open the valve and then holds pressure. Then I close valve, and person inside Jeep releases pedal. Process is repeated until no more air is coming out.

Drivers rear is done next the same way. Keep in mind the brakes were bleed before this, so there should be a good pedal feel (i.e. should not go all the way to the floor).

Now once I get to the front passenger, the first time I open the valve and the person inside the Jeep applies the brake pedal, it goes all the way to the floor. As I continue bleeding this wheel cylinder, along with the front drivers this does not get better and the pedal continues to go to the floor.

I fully understand that the first time (or two) I bleed the brakes the pedal will go to the floor as there is a lot of air in the system. My point here was the brakes have been bled many times so there should be a hard pedal. And with the back two there is, but once I get to the front it starts to go to the floor.

 

[northwestxj]

It sounds like a bad master cylinder to me. :/

Thanks for a good suggestion, that's what I'm leaning towards to.

 

[88 Wagonman]

You said that you are replacing this master and booster because the old one went bad. What were the symptoms of the old one going bad? Is it possible that the old one is still ok and there is in fact another problem that has the same symptoms as a bad master cylinder?

 

[northwestxj]

You said that you are replacing this master and booster because the old one went bad. What were the symptoms of the old one going bad? Is it possible that the old one is still ok and there is in fact another problem that has the same symptoms as a bad master cylinder?

I had no issues with the previous setup. The reason why I had to replace the MC and booster is because the old MC leaked fluid into the brake booster. It would leak almost a whole reservoir of fluid overnight, due to a bad seal(s).