Prop, valve?

whitehorseupnorth

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Sep 9, 2000
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Maine
I was wondering if I can get rid of the stock proportioning vavle. I have rear disc brakes and a line-loc. So there rears have an aftermarket PV and there is only one front line going through the stock one. I figure I can just get rid of it. Anyone do this? Any adverse affects?
 
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Well if you remove the rear line from the stock valve and I would assume you are also talking about removing the line from the master cylinder. The valve needs pressure on both sides of the piston. If you lose pressure on either the rear or front of the master cylinder then the valve diverts pressure from the working side to the non working side so you can still stop the vehicle. This is a safety measure. What you would need to do is install a front valve and then you could remove the entire stock unit.
 
93 LX said:
Well if you remove the rear line from the stock valve and I would assume you are also talking about removing the line from the master cylinder. The valve needs pressure on both sides of the piston. If you lose pressure on either the rear or front of the master cylinder then the valve diverts pressure from the working side to the non working side so you can still stop the vehicle. This is a safety measure. What you would need to do is install a front valve and then you could remove the entire stock unit.

I have a 2 port master, same as the 94-95's. The stock PV is gutted on the rear brake side. I have the wilwood PV for the rears. What I'am talking about is removing the one front line that go's through the stock PV. I think it's the right wheel. I figure if the left isn't going through the PV why should the right? It's setup this way from the factory. Ever notice when you nail the brakes, only one tire locks up.
 
You have already removed the PV from what you said in the last post.

what is the issue?

First off, the block you are talking about is called a combination block. It houses the PV and differential pressure valve -- or shuttle valve.

When you install an aftermarket adjustable unit, you only want one PV in the system. So you remove the stocker and install the FMS M2450A plug

Oh, did you install one of those? If you did not, look at the stock endcap. There is a hole in it with a rubber plug. Thus the solid FMS cap resolves that issue.

Back to the block, you should leave that in there. Why? Safety reasons! If you lose pressure on one system (primary or secondard) the valve will trip and block off fluid to the bleeding system. Thus you will still have some kind of brakes.

If you want to remove it, knock yourself out. But there really is not a good reason to.

Ever notice when you nail the brakes, only one tire locks up.

Not after converting to a 2 port setup correctly. Also be sure all calipers are working properly and bleed the brake correctly.
 
I allready gutted out the stock unit on the rear side and plugged the end cap. As of right now there is only one line going thru the combination valve that is being "proportioned" if you will. The reason I want to get rid of it, is because of looks and it really only serving a purpose on one wheel on the car. Can't I get a aftermarket valve like I have for the rears? I understand the what can happen if removed, but then again how often does someone lose all the thier brakes?
 
YOu took out the wrong parts homes!

You removed the shuttle valve. Since you did everything wrong, that is why you are having issues with one wheel lockups.

You can remove it, but why? Do you not value safety?

The way you have bastardized your brakes now, it only takes 1 leak in the system to drain the fluid from everything. Thus no brakes. Stock it would take a leak in the primary and secondary systems to result in the same failures.
 
Matt90GT said:
YOu took out the wrong parts homes!

You removed the shuttle valve. Since you did everything wrong, that is why you are having issues with one wheel lockups.

You can remove it, but why? Do you not value safety?

The way you have bastardized your brakes now, it only takes 1 leak in the system to drain the fluid from everything. Thus no brakes. Stock it would take a leak in the primary and secondary systems to result in the same failures.
I may have said it wrong. I did it exactly the way your website shows and I don't have problems with the front brakes locking up. I removed the insides of the combination valve on the rear side. Don't need them because of the aftermarket PV. Is this right so far? So now I have the front line from the MC to my line-loc. From there the line go's the LF wheel and the other go's to the combination valve. Does this sound right? I have no problems with my brakes at all. So your telling me that if remove the combination valve from the RF wheel I will have problems if there is a leak?
 
whitehorseupnorth said:
I may have said it wrong. I did it exactly the way your website shows and I don't have problems with the front brakes locking up. I removed the insides of the combination valve on the rear side. Don't need them because of the aftermarket PV. Is this right so far? So now I have the front line from the MC to my line-loc. From there the line go's the LF wheel and the other go's to the combination valve. Does this sound right? I have no problems with my brakes at all. So your telling me that if remove the combination valve from the RF wheel I will have problems if there is a leak?

Again, if you remove the rear facing side, that is the SHUTTLE VALVE!

If so, you removed the wrong parts. You need to do it on the front side -- that is the stock PV.

You still need the shuttle valve for safety. You dont need the stock PV since you are running an adjustable one.

Other than that, seems you have screwed all the lines up. The primary port is the front brake system. That is the port closest to the firewall. Both front brakes have to T off the primary system.

The secondary system is where the PV is running through since that is the rear brakes. So from the front port (secondary system) it goes through the PV, snakes down tunnel and T's at the rear axle.
 
First off, I didn't screw all the lines up :rolleyes:. The only thing I didn't do was tap the rear of the combination valve for RF brake. Other than that I did every thing right. I know what I need to do if I want it done right, if there is such a thing. Thanks.