Brakes no longer work after tub swap

[Impaqsol]

Hi Everyone,

Hope anyone can help. I change the tub on my Jeep TJ (rusted) and obviously took the old Power Brake Booster and Master Brake cylinder off the old tub (working condition) and installed in the new tub. I change all the back ( Drums and shoes )and front brakes ( disc and pads ). I have bleed the lines and it seem that there is no air in the lines anymore ( all 4 brakes done ), but the pedals still goes all the way down. I can tell it still not working correctly.

What I'm missing ? Could be that the old Booster and Master are not good anymore. I just don't want to go ahead and buy new ones and issues keep persisting.

Any help would be greatly appreciated.

Rad

 

[Mike_H]

Did you bleed the master? I swapped a tub this winter, replaced all my lines. When I pulled the booster and master, I drained the fluid from the master completely. Then I bench bled the master before re-installation. Finally, bleed the air out of the lines and calipers.

 

[defenderu]

Someone in here who gets @ all the time will likely know the answer.

 

[Wtrask]

If you separated the master from the booster check to make sure the booster is fully engaged into the master cylinder. Also if the pedal goes to the floor how do you know any air is coming out? There is no way all the air is out if the pedal goes to the floor.

 

[Impaqsol]

If you separated the master from the booster check to make sure the booster is fully engaged into the master cylinder. Also if the pedal goes to the floor how do you know any air is coming out? There is no way all the air is out if the pedal goes to the floor.

So when I'm bled the brakes and the brake pedal is press and I open the valve for air to come out (behind brake drums and disc), only brake fluid come out. That's why I know that there is no air in the brake lines anymore.

 

[Impaqsol]

If you separated the master from the booster check to make sure the booster is fully engaged into the master cylinder. Also if the pedal goes to the floor how do you know any air is coming out? There is no way all the air is out if the pedal goes to the floor.

Will disassemble the master and booster again to check if they are fully engaged. Will keep you posted.

 

[FarFire70]

Did you bench bleed master?

 

[Impaqsol]

Did you bench bleed master?

So I used to old master cylinder, so I didn't need to bleed. Now I change the master without success, change the power booster no success. Don't know what to do. One thing I have notice is that when I connect the power booster vacuum to the manifold brake pedal goes complete down without pushback, but if I take off and cover it, it does get just a little better, but still no brake.

 

[Impaqsol]

Will disassemble the master and booster again to check if they are fully engaged. Will keep you posted.

If you separated the master from the booster check to make sure the booster is fully engaged into the master cylinder. Also if the pedal goes to the floor how do you know any air is coming out? There is no way all the air is out if the pedal goes to the floor.

I have checked and disassembled the master and booster ( I just changed them both ) and no success. Brake pedal still goes to the floor. I bled the new master and all brake again. When bleeding each brake no air was coming out just brake fluid, meaning there should be no air any more in the system. Don't know what else to do.

 

[mrblaine]

So I used to old master cylinder, so I didn't need to bleed.

Not true at all. If the old master lost fluid to the point where the bore was not full of fluid, you need to bench bleed it.

Now I change the master without success, change the power booster no success. Don't know what to do. One thing I have notice is that when I connect the power booster vacuum to the manifold brake pedal goes complete down without pushback, but if I take off and cover it, it does get just a little better, but still no brake.

Does the pedal go to the floor by itself or just when you push on it with vacuum applied?
Fluid will only come out when bleeding when the bleed ports are on the bottom instead of the top. My money is you have the calipers upside down since that is the new part of the system.

 

[Impaqsol]

Not true at all. If the old master lost fluid to the point where the bore was not full of fluid, you need to bench bleed it.

Does the pedal go to the floor by itself or just when you push on it with vacuum applied?
Fluid will only come out when bleeding when the bleed ports are on the bottom instead of the top. My money is you have the calipers upside down since that is the new part of the system.

You were completely CORRECT !!!!! I have not notice that the calipers were upside down. You have safe me. I have done a restoration on the jeep and that was the last thing that had be back. Finally was able to take out and tried everything out. Thanks for the help. See pic of the final product.