line lock orientation

-
diymirage

diymirage

HP@idle > hondaHP@redline
Joined
Oct 12, 2012
Messages
34,218
Reaction score
43,359
Location
michigan
hey friends, while this snowball is rolling along, i figured i now is as good a time as any to install a line lock

my plan is to install it on the rear brakes, locking brake fluid OUT of the system, rather then in, so i can control roll out after the burn out (and maintain proper brake lights)

now, if i do it like that, will i need to install it backwards?
(the instructions say one side should point towards the master cylinder, the other towards the brakes)

i guess my main concern is, is this valve CLOSED when closed, or does it act as a one way valve, when it is closed?

does that make sense?


and would anyone know off hand what size thread is on the rear distribution block on a 8 3/4 with 10 inch brakes?
 
diymirage said:
hey friends, while this snowball is rolling along, i figured i now is as good a time as any to install a line lock

my plan is to install it on the rear brakes, locking brake fluid OUT of the system, rather then in, so i can control roll out after the burn out (and maintain proper brake lights)

now, if i do it like that, will i need to install it backwards?
(the instructions say one side should point towards the master cylinder, the other towards the brakes)

i guess my main concern is, is this valve CLOSED when closed, or does it act as a one way valve, when it is closed?

does that make sense?


and would anyone know off hand what size thread is on the rear distribution block on a 8 3/4 with 10 inch brakes?
Click to expand...

I don't know about all of them but the one I have is metered one way and full stop the other way.
Meaning if I have the lock activated I can press the brakes and they will apply normally, but will not let go until I release the button.
If I want to add more braking I can press the pedal with the lock still on and add pressure, but it only lets braking off when I let off the lock button.


That make sense?

For what you want you need one that stops the fluid completely both ways.
 
diymirage said:
my plan is to install it on the rear brakes, locking brake fluid OUT of the system, rather then in, so i can control roll out after the burn out
Click to expand...

So you want to activate the roll control so the rear brakes don't engage, correct? If that's the case the outlet for the rear (out of distribution block) go into the "in" on the unit, then "out" to rear brakes.

You would need to activate the unit before stepping on the brake pedal keeping fluid out of the rear (I think, lol), then press on the brake pedal to activate the front brakes.

I have mine installed on the front, I press the pedal, apply the button and release the pedal. My back brakes are now free. The front remain locked until I release the button.
 
Bad Sport said:
So you want to activate the roll control so the rear brakes don't engage, correct? If that's the case the outlet for the rear (out of distribution block) go into the "in" on the unit, then "out" to rear brakes.

You would need to activate the unit before stepping on the brake pedal keeping fluid out of the rear (I think, lol), then press on the brake pedal to activate the front brakes.

I have mine installed on the front, I press the pedal, apply the button and release the pedal. My back brakes are now free. The front remain locked until I release the button.
Click to expand...

You are right it would work even with the one I have since it would only be for stopping the fluid.
When not activated it would be open anyway and work normally.
So what would normally be the fluid in direction would be facing the rear brakes for locking fluid out of them.
(you would put it in the line backwards)
 
10 x 2s will not resist power very well, through the proportioning valve. The rear pressure is limited to about 15/20 percent of the front, 25% tops. At 400psi on the front, the rear will get about 80 psi, and thru 7/8 wheel cylinders, you would get 48 pounds of force delivered to the shoes. That is not much at all.
I weigh 220, and each sneaker gets 110 pounds of force,when I'm standing still; about 2.3 times as much. And a pair of my sneakers has about 30% more frictional area than all four rear shoes.And that is if the rear shoes fully conform to the drum, which is highly unlikely.
Jus saying
Oh chit. you want to keep fluid out.
In that case, might I suggest a ball valve?
Oh jeepers that won't work either.
See if you are able to prevent the fluid from moving out of the M/C, and into the rear line, then the Brake pedal will only move far enough to close the compensating port, and then you have a hydraulic lock situation. The piston cannot continue to move as the inter-piston area is full of fluid and cannot move, nor can the forwardmost piston due to the closed valve. Therefore nothing moves, no brakes at all. And no brakelites probably either.
 
Last edited:
dirt racers run them on right front hooked up backwards to help turn the car on corner entry works slicker than snot on a tin roof...dont see no resin it wont work for you way your planning!
 
Wilwood makes what you need. It shuts off your rear brakes. I have one on my car.
 
Last edited:
this is the unit i ordered

JEGS Performance Products 63000: Stage Control Solenoid Valve 2-Port Brass Valve | JEGS

so, the general consensus is, it should work, if plumbed in backwards, because it is a one way valve when closed, and i want to keep the brake fluid before the line lock, and not after it, correct?


i there any merit to @AJ/FormS argument that this would render the master cylinder inop?

(FWIW, i was intending to install it on the rear axle, where the flexline goes into the distributor black)
 
diymirage said:
i there any merit to @AJ/FormS argument that this would render the master cylinder inop?
Click to expand...

I was thinking about that when I posted yesterday, and I think it will work fine.
(If you have a two peice master cylinder plunger with the spring in the middle) because the fluid being stopped to the rear would stop the front part of the piston from moving, but the rear part of the piston for the front brakes would still travel by compressing the spring in the center.

If the master has one solid piston the fluid being stopped would stop the fronts from applying.

Pretty sure anyway.

pistona.jpg
 
That chamber is also full of brake fluid,which is....... in-compressible.
But the compensating port is at the rearmost part of that chamber. As soon as the rearmost piston covers the port, the fluid moves out to the front calipers. If the caliper pistons are in close proximity to the discs, requiring a minimum amount of fluid to do their thing, then it should work.
But if seal retraction or knock-back is excessive, or you have huge calipers or with multiple pistons, and or you are using a tiny m/c;then that rearmost piston may travel forward and hit the stop on the frontmost piston, and then everything will lock up solid. This may occur before there is sufficient fluid pressure in the front brake system, to hold the car on the line;
IDK.
I tried something like this on my car once, and it didn't work on the KH 4 pistons with a 7/8 M/C.
Perhaps it would have, with a bigger M/C, or if I had shortened the mechanical stop. Or tightened up the bearings. That was a long time ago.

TB
I assume your arrow at "because of this" is pointing to the mechanical stop, and not to the piston return spring.
 
TrailBeast said:
Note that all I had to do was cut the line and feed it to the lock (one end of it in, and the other end to the out)
The lines are installed in the line lock with 3/16 steel compression unions, and one end of each union has the nut removed and is threaded directly into the lock body.
Click to expand...

TrailBeast said:
The line lock I have came with all kinds of adapters and crap that I just wasn't willing to stack up to make something work.

The threaded line holes in the lock are 1/8 NPT and the threads on the 1/8 steel compression fittings (mandatory for brake lines) are the same thread pitch but not NPT.
Click to expand...

so IF i got this right, you used something like this
Pack of 5. 1/8" Male NPT x 1/8" OD Tube Compression Fitting. | eBay

but of an unknown size?

does anyone know the OD of the stock brake lines on a 71 slant 6 duster with 9 inch drums all around?

(no, i dont have calipers, i know, i really should buy some)
 
diymirage said:
so IF i got this right, you used something like this
Pack of 5. 1/8" Male NPT x 1/8" OD Tube Compression Fitting. | eBay

but of an unknown size?

does anyone know the OD of the stock brake lines on a 71 slant 6 duster with 9 inch drums all around?

(no, i dont have calipers, i know, i really should buy some)
Click to expand...

More like this (actually exactly these)
3/16" High Pressure 5,000 Psi Black Steel Compression Union | eBay

Brass isn't recommended for brake lines, so these are 5,000 lb steel and one end without the nut on it threads right into the line lock body.
You will have to use thread sealer as the union isn't pipe thread but screws right into the pipe thread of the lock.

And 3/16 is correct on the stock line size.

I fit the bottom line first, then filled the lock with fluid and connected the top line so I didn't even have to bleed the brakes after the install.
I guess some people have to go through a lot of work before they feel they accomplished something.:D
This was super simple and works perfect without any extra fittings flares or line sections.
I simply cut the line and fed the two ends into the compression unions.
I also have brake lights when the lock is active, but didn't install any extra tubing, flare any lines, and no pressure switch.

Figure that one out. :D

lock.jpg
 
Last edited:
I liked the ones I listed because they were 1/8th NPT and would eliminate the need for sealant but I'll look for steel ones, kinda like a mix between the two

As for the brake lights, you need power to operate the line lock to begin with...shouldn't be to hard to incorporate the tail lights into that circuit, no?
 
diymirage said:
I liked the ones I listed because they were 1/8th NPT and would eliminate the need for sealant but I'll look for steel ones, kinda like a mix between the two

As for the brake lights, you need power to operate the line lock to begin with...shouldn't be to hard to incorporate the tail lights into that circuit, no?
Click to expand...

Sure but what happens when you apply the brakes?
I have a single wire I made with a diode in it so the power from the lock goes to the brake lights but when the brakes are applied power can't come back up the wire and activate the lock.
Of course you won't need to do anything because you want to use the pedal to hold the car.
You were pretty darn close. :D

baseimage.jpg
 
lol, i hadnt considered the issues that could result from the line lock coming on when you step on the brakes
now, if we could find a way to disengage it when we get on the gas (perhaps by running it off of engine vacuum) we could build an autonomous parking system, much like the hill assist you see on certain cars


in the mean time, im still not sure where i want to install the linelock, front or rear brakes
 
You must log in or register to reply here.
-

Back
Top