Has anyone bypassed the 4040 valve and gone directly to the MC? I don't see why this can't be done and why the 40/40 is needed. I'm sure someone has attempted it or thought about it. Maybe it is not feasible with this MC and the volume of fluid it pushes but it's done on motorcycles so i don't see why it would be different on a car.

 

More information on the car? Some prop valves are dummies, but that is on abs setups so you most likely wouldn't be running directly to the master cylinder anyway.

You need some sort of pressure reduction to the rear brakes. I don't screw with motorcycles, but last time I checked they had independent front and rear brakes, so I don't see why there would be a proportioning valve. The rider's brain does the brake proportioning.

 

The car is an integra with abs delete. The weep hole started to sweat finally for no reason as it is a ticking time bomb in my opinion. So i have to get another one from the dealer and frankly i don't want to keep doing this as it is a pain in the ***.

Yes you are right motorcycles have 2 MC's one for front brakes and one for rear. The way i think the pressure reduction can be done going back to the rear calipers would be reducer fittings but judging by the fact only one person responded to this thread it probably means no one has done it or it is just not feasible. I'm just fed up with the brakes on this car and looking for a long term fix. It was bad enough making custom lines with everything in the car now i have to take them all off and redo it b/c of this leaking valve

 

The problem with using an orifice type device is that the stock valve does not have a perfectly linear behavior. There is a knee point where, if graphed, the slope of the line describing the ratio of input to output pressure decreases. In other words, output pressure may be the same up to, say 500 or so psi, and then the prop valve begins to do its thing. Maybe at 700 psi input the output is only 600. At 800psi input it would be about 680, and so on.

Here is a quick example from Google images:



If you went with a simple orifice-type restrictor you would potentially have to pick a part of that line where you wanted to be in the correct proportion. There are also other fluid dynamic effects that would need to be considered by using a simple orifice, but those are most likely beyond the scope of this thread.

 

I have taken the 4040 apart and there is a piston/valve system in there with a spring, so you are right it is not a leaner pressure going to the rear. I'm thinking based on your post and my hastiness and hate for having to redo the brakes again it is probably more trouble than it is worth. I'm sure i can come up with a way to regulate the fluid similar to what the valve does but having to re-engineer it is going to be a trial and error setup which i don't care for. Thanks for your input

 

Not a problem. Glad I could help.

 

To expand on what spAdam is talking about, Stop Tech White Paper Brake Bias and Performance, Why Brake Balance Matters.

 

That paper is a good read. Almost forgot about it, thanks for posting up.