Line Lock problem

[ibsorgn]

Hello,
I have a 72 Satellite that I installed a line lock on the front disc brakes. I installed it before the distribution/proportioning block. After installing I found the instructions and to my surprise it read that the LL should be installed after the d/p block. I don't understand the logic but I've found that the LL does not like to release but yet I hear the solenoid click. Even with the power disconnected the LL will hold the brakes. I'm wondering whether the LL is defective or the proportioning valve is causing something to happen. Only way I can release the brakes is to loosen the brake line from the master cylinder to release the pressure. Any ideas out there as to what is going on.

 

[66Satellite47]

Very interesting. I have mine upstream of the dist block. I may need to re-think that.

 

[Fran Blacker]

Is your the distribution/pressure differential block.
It has a switch on it that lights up a light to tell you that front or back brake aren't working right?
I have my l/l before it didn't have a prombem yet. Haven't used it much, so I'll be watching. Picture of block your using would help.

 

[Fran Blacker]

One thing it would turn the dash brake problem light if you have Distribution/pressure differential block. As long as you understand that don't see it as a problem. Factory p/p valves are another matter, I can't answer.

I'm posting some of the directions, other parts didn't seem to apply.
Edit: When you let up on the brake the switch will move reducing pressure on front brakes, how much? That's if is before d/pd valve.

 

[ibsorgn]

Very interesting. I have mine upstream of the dist block. I may need to re-think that.

I assume you mean between the master cylinder and the distribution block. If it doesn't hang up or stick I would assume you are okay. My problem is the LL somehow sticks whether powered or not, that's why I'm asking if the problem is related to the proportioning valve.

 

[ibsorgn]

Is your the distribution/pressure differential block.
It has a switch on it that lights up a light to tell you that front or back brake aren't working right?
I have my l/l before it didn't have a prombem yet. Haven't used it much, so I'll be watching. Picture of block your using would help.

Is pressure differential block aka proportioning valve? Want to make sure we are talking apples and apples. To answer your question, it does have a switch (probably pressure type). What type of LL do you use?

 

[Mike67]

So lets think about it from how you say its plumbed ( on the line side) of the prop valve.
You apply brakes, activate ll & release the brake correct?
When you deactivate ll, pressure is still being applied to front brakes correct?
Sounds like the slide (piston) in the prop valve is sliding back to its normal position and basically hydrolocking the front brakes since there is no grooved portion of the slide to allow the fluid to return to the mc.. Im no brake expert just trying to think through the mechanics of it.
If the solenoid is in fact opening back up ( spring loaded) on deactivation

 

[ibsorgn]

One thing it would turn the dash brake problem light if you have Distribution/pressure differential block. As long as you understand that don't see it as a problem. Factory p/p valves are another matter, I can't answer.View attachment 434534 I'm posting some of the directions, other parts didn't seem to apply.
Edit: When you let up on the brake the switch will move reducing pressure on front brakes, how much? That's if is before d/pd valve.

I don't get a light however it may not be connected or working. To reiterate, the LL will stick when I apply the brakes even if the LL is not powered. Trying to determine if the LL is faulty or by not having it mounted according to instructions is causing the problem. Both you and 66satellite are saying that your LL is mounted b4 the pressure diff block, which according to instructions is incorrect, but are not having problems.

 

[ibsorgn]

So lets think about it from how you say its plumbed ( on the line side) of the prop valve.
You apply brakes, activate ll & release the brake correct?
When you deactivate ll, pressure is still being applied to front brakes correct?
Sounds like the slide (piston) in the prop valve is sliding back to its normal position and basically hydrolocking the front brakes since there is no grooved portion of the slide to allow the fluid to return to the mc.. Im no brake expert just trying to think through the mechanics of it.
If the solenoid is in fact opening back up ( spring loaded) on deactivation

View attachment 435422

Interesting. So you don't believe it is in my LL it maybe in the d/p block.
1st ? - yes
2nd ? - yes
Remember my front brakes will lock even when the LL is not powered

 

[Mike67]

I miss understood, I thought it was only happening when you released the lock. That line lock is just a simple solenoid valve, a coil, stem, seat and spring...
You could pull it and connect an air line to inlet and a gauge on the outlet; pressurize it then disconnect the air and gauge should go to 0psi. Reconnect the air, power the solenoid and disconnect the air and the gauge should hold..

 

[Fran Blacker]

This is what I call a distribution block. It has a switch to tell front or rear brakes

aren't working.

 

[ibsorgn]

I miss understood, I thought it was only happening when you released the lock. That line lock is just a simple solenoid valve, a coil, stem, seat and spring...
You could pull it and connect an air line to inlet and a gauge on the outlet; pressurize it then disconnect the air and gauge should go to 0psi. Reconnect the air, power the solenoid and disconnect the air and the gauge should hold..

Curious isn't it? Something is causing that plunger or stem closed, but don't know what. I have pulled the LL and all is fine.

 

[ibsorgn]

This is what I call a distribution block. It has a switch to tell front or rear brakesView attachment 435498 aren't working.

See Mike67's post - and my photo as that is the device I'm referring to.

 

[Fran Blacker]

As you can see from Mike67's picture a prop valve is much more complex than dist block.
To put L/L past the prop valve you'd have to run both lines to a tee then L/L then to a tee to split it to each wheel. Must be a better way.
Option: Remove factory prop valve put an adjustable prop valve near master on rear brake line? Put L/L on front brake line out of mc then to a tee for front brakes?

 

[Mike67]

Prop valves are often called Distribution blocks, while they do distribute, they are metered for a specific purpose which makes them proportional. Some can be rebuilt some cant.
Go to the local parts house and get a fitting that will allow you to tie it back in as it was originally.and see if the problem persists....then youll know for sure.

 

[ibsorgn]

As you can see from Mike67's picture a prop valve is much more complex than dist block.
To put L/L past the prop valve you'd have to run both lines to a tee then L/L then to a tee to split it to each wheel. Must be a better way.
Option: Remove factory prop valve put an adjustable prop valve near master on rear brake line? Put L/L on front brake line out of mc then to a tee for front brakes?

That's why I referred to it as d/p block (distribution/proportioning block.) I see that my original question has morphed into a installation answer. My original question is not one of how to install, but what is causing the front brakes to not release when the LL is part of the circuit.

 

[ibsorgn]

Prop valves are often called Distribution blocks, while they do distribute, they are metered for a specific purpose which makes them proportional. Some can be rebuilt some cant.
Go to the local parts house and get a fitting that will allow you to tie it back in as it was originally.and see if the problem persists....then youll know for sure.

In post #12 I did that. My original question still remains unanswered - but maybe there is no answer. Puzzeling that others stated they installed the same way I did without having a lockup problem but maybe their LL was somehow different than mine or the problem has yet to surface.

 

[JEDS67]

I have been having the same problem so I bought a rebuild kit and it solve the problem for a little while but it has slowly coming back. Going to order another kit and if it comes back I will do it again and if doesn't fix it I will buy a new one.

 

[ibsorgn]

I have been having the same problem so I bought a rebuild kit and it solve the problem for a little while but it has slowly coming back. Going to order another kit and if it comes back I will do it again and if doesn't fix it I will buy a new one.

What did you rebuild? What failed or started to fail?

 

[Mike67]

So if you didn't have this problem before installing my GUESS... would be that the prop valve was damaged by the LL being installed incorrectly. There are o rings and springs in the prop vavle, here is the actual cutaway for a 70-76 mopar and a link that might help figure it out.
https://www.musclecarresearch.com/1970-76-mopar-combo-valve-autopsy