Brake Junction Block

[MileHi4w4]

Hi All,

I have a 2005 Liberty Sport and I'm looking for some information about the brake "Junction Block" (this is what the service manual calls it so I'm going to refer to it as so). I'm not getting any brake fluid to the rear brakes and I've already troubleshot it down to the block. The problem I'm having now is that I don't know how to replace/fix it. It's been discontinued and after a ton of searching I can't find any solutions. I'd appreciate any ideas.

 

[LibertyTC]

Welcome to the forums.
Have you tried replacing the Master Cylinder?
Do you have a non ABS brake block with 5 lines or ?

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[MileHi4w4]

Yes it's non ABS with 5 lines. I did just replace the Master, that was probably part of the problem but fluid is still not going through the block.

 

[turblediesel]

Might need to pre-bleed the master cylinder. There's a way to do it with small pieces of brakeline connected to the master cylinder outlets. The brakelines loop around into the master cylinder reservoir below fluid level. Pump the master cylinder until there are no bubbles and then install it.

Sometimes a new master cylinder will just compress an internal bubble of air and there isn't enough force left to do anything hydraulic.

 

[LibertyTC]

If in doubt, let the shop power bleed the air bubbles out. They got the right tools for this kinda job.

 

[MileHi4w4]

Well surprisingly I got it figured out!. I ended up just removing the block and cleaning out the valve. I think it was just really stuck.
Appreciate the replies!

 

[LibertyTC]

Noted. Did not know that the block's valve could be a choke point.
I have seen black fine particulate matter at the bottom of the master cylinder before though.
Every year in fall, I normally suction out all the DOT3 from the master, to keep fresh fluid in the system.

 

[JeepJeepster]

I do believe the proportioning valve within the combination valve can get stuck in one direction or the other if you have a leak. Its the valves way of keeping you from running out of brake fluid.

I have no idea how you rest it.

 

[uss2defiant]

isn't that block on the rear just a Tee?

 

[MileHi4w4]

I do believe the proportioning valve within the combination valve can get stuck in one direction or the other if you have a leak. Its the valves way of keeping you from running out of brake fluid.

I have no idea how you rest it.

I saw a video of a guy blowing air into the right rear bleed valve, that didn't work for me. I'm honestly not completely sure what the problem really was, but cleaning it did he trick haha