I tried swapping my prop valve to 4 wheel disc once i finished the axle. different size fittings. decided instead to swap the guts and put my old one back on. along with a new master cylinder. can anyone tell me why the lower rear line erupts fluid everytime you hit the brakes? it isn't stripped, crossthreaded, and is tightened down all the way... It is a 91 camaro and if I dont get this solved then the whole thing goes to a scrap yard and I have no cash for a car right now

 

What is exactly the problem? Is the brake system leaking from the master or the prop valve?

If you have an original drum brake vehicle, and you swap to disk, without a new prop valve you are pushing too much pressure to the rear, as disc brakes take far less pressure (which directly equates to far less fluid) than drums. This may cause a rear end lockup while braking and I suppose fluid loss if you have stock rear brake lines. Most of the time, the hydrolic system is up to the pressure of disc breaks, and rear lockup will occur before your system starts leaking, but this is assuming that the overall system is in good working order. Hope this helps,

 

that does clear up the confusion about pressure. everyone seems to conflict w/ eachother on that. the rear system is slightly modified with better lines because the ones on the axle were shot. So no leaks there. The lines right under the prop valve were causing a problem when you press the brakes, fluid gushes out of one of the ports.

 

if fluid is coming out of it, its simply not sealing. The flare it wrong or not made right.

are the brake lines stock? they are metric bubble flare right? not 18-27 inverted flare? the inverted flare 1/8-27 threads are very similar to the metric ones anbd will thread together, but the flare will not seal.

If the lines are correct, the flare is damaged or made wrong, possible the prop valve is damaged.

take the line off that leaking and see what the bubble flare looks like, see if its cracked or distorted in any way, has a lip on it ect.

 

well its the same shell of a prop valve i swapped the internal springs. so this is the equipment that came off the car. idk exactly the dimensions or whatever. so they should fit perfect considering they've been there for 20 years. the flare is fine. got another disc/drum prop valve to swap to see if it is the internals or if i cross threaded and didn't realize it. we'll see what happens

 

if this doesn't work, the next step is to totally gut the prop valve and install an aftermarket adjustable inline with it

 

thats what i did.

are you sure the fittings are leaking and not the plug at the end of the prop valve?