Brake Junction Block

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

MileHi4w4

New Member
Joined
Jul 14, 2021
Messages
4
Reaction score
2
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

Well-Known Member
Staff member
Moderator
Joined
Oct 24, 2008
Messages
9,191
Reaction score
1,836
Location
B.C. Canada
Welcome to the forums.
Have you tried replacing the Master Cylinder?
Do you have a non ABS brake block with 5 lines or ?
You must be registered for see images attach
 

MileHi4w4

New Member
Joined
Jul 14, 2021
Messages
4
Reaction score
2
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

memberable
Joined
May 31, 2015
Messages
3,421
Reaction score
1,159
Location
Alaska
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

Well-Known Member
Staff member
Moderator
Joined
Oct 24, 2008
Messages
9,191
Reaction score
1,836
Location
B.C. Canada
If in doubt, let the shop power bleed the air bubbles out. They got the right tools for this kinda job.
 

MileHi4w4

New Member
Joined
Jul 14, 2021
Messages
4
Reaction score
2
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

Well-Known Member
Staff member
Moderator
Joined
Oct 24, 2008
Messages
9,191
Reaction score
1,836
Location
B.C. Canada
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

Full Access Member
Joined
Dec 15, 2004
Messages
8,933
Reaction score
328
Location
Dem hollers in Ky
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.
 

MileHi4w4

New Member
Joined
Jul 14, 2021
Messages
4
Reaction score
2
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
 

Latest posts

Members online

Top